Introduction to

workstudy

Ihtud (rcvised) edition

International Labour Officc Geneva

Third edition copyright @ International Labour Organisation 1978
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ISBN 92-2-101939-X

First published 1957

Second edition 1969
Third edition 1979

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 Preface
to the third (revised) edition

Writing a bpok on work study which can be psed all over the world by
persons trained in different countries with different systems and different ter-
minologies is no easy task. To make this book as widely acceptable as possible,
therefore, it has been felt advisable to present the subject-matter in a reasonably
simplified manner and to enrich the text with numerous examples of work study prac-
tice, a large number of which are based on the experience of ILO management
development advisers engaged in work study in many countries.
The original version of this book, published in 1957, was intended mainly
for use by persons attending courses in work study at management development and
productivity centres in the numerous developing countries to which ILO technical co-
operation missions were attached, and to provide basic teaching material for members
of the staff of these centres. Since 1957 the book has met with considerable success,
easily topping the list of best-selling books published by the ILo. To date, over
200,000 copies have been sold in English, French and Spanish, three of the working
languages of the ILO, and the book has been translated into a number of other
languages, including Arabic, Japanese and Korean. Although originally intended for
use in developing countries, it has become a standard introductory textbook in many
institutions in developed countries as well.
Some ten years after the original edition was published, an enlarged and
revised edition was produced; this aimed at strengthening certain aspects of the book,
particularly the part on work measurement. However, the original intention that the
book should be an introductory text for use mainly for educational purposes was
adhered to.
Some 20 years after the publication of the first edition, the present com-
pletely overhauled and revised edition has been prepared. The basic aims of this
revised edition are to bring the contents up to date, to modify the book's purely intro-
ductory character, and to make it equally useful for the work study practitioner and
for the teacher and student, whilst retaining the simplified approach to the explana-
tion of complex problems. To this end, the chapter dealing with working conditions
has been completely rewritten to take account of current advances in knowledge in
this field. Similarly, the part dealing with work measurement has been radically
modified to accommodate new ideas, and new chapters have been added to deal with
work sampling, with predetermined time standards and with standard data. Finally, as
a corollary of this new approach, work study has been examined in the light of
modern developments in work organisation which aim at reconciling productivity with V
 PREFACE TO THE THIRD {REVISED) EDITION

job satisfaction, thus scotching the notion that the only use of work study is to in-
crease productivity. A chapter on new forms of work organisation has therefore been
added. This is the first time that any book in this field has shown that work study has
a contribution to make towards making work more human as well as towards raising
productivity.
The original edition of the book was prepared by C. R. Wynne-Roberts, at
the time Chief of the Management Development Branch of the ILO, in collaboration
with E. J. Riches, former Treasurer and Comptroller to the ILO. Several members of
ILO management development teams helped to prepare very detailed and valuable
comments, among them Hans Fahlstr6m, L. P. FerneY, HY Fish, C. L. M. Kerk-
hoven, J. B. Shearer and Seymour Tilles. Several others contributed valuable
criticisms and commentaries, particularly F. de P. Hanika and Winston Rogers, and
the late T. U. Matthew.
The second (revised) edition was prepared by R. L. Mitchell, then an offrcial
of the ILO Management Development Branch, who, as chief of ILO missions to India
and Turkey, had used the original version extensively in teaching work study and was
therefore able to perceive the extent of the revisions needed. The revision also
benefited from the advice and collaboration of J. B. Shearer, who also at that time was
an official of the ILO Management Development Branch.
The third (revised) edition has been conceived and edited by George Kana-
waty, the present Chief of the ILO Management Development Branch, who has also
written several parts of the new material. Acknowledgement is also due to John Bur-
bidge, Fred Evans, Rolf Lindholm, Luigi Parmeggiani and Peter Steele for their
valuable contributions, all of which have helped to ensure that this book, in its ex-
panded and updated form, retains its function as a basic text on the principles and
techniques of work study.

VI
 Contents

Preface to the third (revised) edition v

PART ONE. PRODUCTIVITY AND WORK STUDY

l. Productivity and the standard ofliving 3

l.The standard of living 3
2. Requirements for a minimum satisfactory standard of living 3
3. What is productivity? 4
4. Relationship between increased productivity and higher standards of living 6
5. Productivity in industry 6
6. Thebackgroundofproductivity 7
7. The attitude of the workers 7

2. Productivity in the individual enterprise 9

l. Resources at the disposal ofan enterprise 9
2. The task of the management l0
3. The productivity of materials l0
4. The productivity of land, buildings, machines and manpower 12
5. How the total time of a job is made up
13
6. Factors tending to reduce productivity 16

3. Reducing work content and ineffective time 2l

l.Reducing work content due to the product 2l
2. Reducing work content due to the process or method 22
3. Reducing ineffective time due to the management 22
4. Reducing ineffective time within the control of the worker 25
5. Inter-relationship of the various methods to reduce ineffective time 27
4. Work study 29
l. What is work study? 29
2. Work study: a direct means of raising productivity 29
3. Why is work study valuable? 30
4. Techniques of work study and their relationship 33
5. Basicprocedureofwork study 35

5. The human factor in the application of work study 37

l. Good relations must be established before work study is applied 37
2. Work study and the management 37
3. Work study and the supervisor 39
. 4. Work study and the worker 4l
5. The work study man 43 vil
 CONTENTS

6. Working conditions and the working environment 47

l. General considerations 47
2. Occupational safety and health organisation 48
3. Safety criteria 48
4. Fire prevention and protection 5 I
5. Working premises 52
6. Cleanliness and good housekeeping 52
7. Lighting 55
8. Noise and vibration 57
9. Climatic conditions 62
10. Exposure tests 68
I l. Personal protective equipment 68
12. Ergonomics 69
13. Arrangement of working time 73

PART TWO. METHOD STUDY

7. Introduction to method study and the selection ofjobs 79

l. Dehnition and objects of method study 79
2. Basic procedure 80
3. Selecting the work to be studied 82

E. Recor4 examine, develop 87

l. Recording the facts 87
2. Examine critically: the questioning technique 99
3. Develop the improved method 106
9. The flow and handling of materials 107
l. Plant layout 107
2. Some notes on plant layout 101
3. Developing a layout 109
4. The handling of materials l2O
10. Movement of workers in the working area 125
l. Fa'ctory layout and the movements of workers and material 125
2. The string diagram 125
3. The man type flow process chart 132
4. The multiple activity chart 136
5. The travel chart 146
I l. Methods and movements at the workplace 153
l.General considerations 153
2. The principles of motion economy 154
3. Classification of movements 157
4. Furthernotesonworkplacelayout 157
5. Notes on the design ofjigs, tools and fixtures 159
6. Machine controls and displays of dials 160
7. Thetwo-handedprocess chart 16l
8. Reorganisation of a workplace by .means of a rwo-handed process chart 165
9. Micromotion study l7l
10. The simo chart 172
I l. The use of lilms in methods analysis 174
12. Otherrecordingtechniques 174
13. The development of improved methods 175
vilt 14. The methods laboratory 176
 CONTENTS

12. Define, install, maintain 177

l. Obtaining approval for the improved method 177
2. Defining the improved method 171
3. Installing the improved method 178
4. Training and retraining operatives l8l
5. Maintaining the new method 182
6. Conclusion 183

PART THREE. WORK MEASUREMENT

13. General remarks on work measurement 187
l. Definition 187
2. The purpose of work measurement 187
3. The uses of work measurement 190
4. Thebasicprocedure 19l
5. The techniques of work measurement 192
14. Work sampling 193
l.The need for work sampling 193
2. A few words about sampling 193
3. Establishing confidence levels 194
4. Determination of sample size L96
5. Making random observations 198
6. Conducting the study 2Ol
7. Using work sampling 2U
t5. Time study: the equipment 205
l. What is time study? 205
2. Basic time study equipment 205
3. Time study forms 2O7
4. Other equipment 215
16. Time study: selecting and timing the job 219
1. Selectingthejob 219
2. The approach to the worker 22O
3. Steps in making a time study 224
4. Obtaining -and recording information 224
5. Checking the method 226
6. Breaking the job into elements 227
7. Deciding on the elements 229
8. Sample size 230
9. Timing each element: stop-watch procedure 232
17. Time study: rating 235
l. The qualified worker 235
2, The'oaverage" worker 237
3. Standard rating and standard performance 239
4. Comparing the observed rate of working with the standard 243
5. What is rated? 244
6. Factors affecting t}re rate of working 245
7. Scales ofrating 247
8. How the rating factor is used 248
9. Recording the rating 250

18. Time study: from study to standard time 251

l. Summarising the study 251
2. Preparing the study summary sheet 252 tx
 CONTENTS

3. Extension: the calculation of basic time 253

4. The selected time 255
5. Completing the study summary sheet 260
6. How many studies? 261
7. The analysis ofstudies sheet 261
8. Work content 263
9. Allowances 264
10. Calculation of allowances 265
I l. Relaxation allowances 266
12. Other allowances 268
13. The standard time 271

19. Setting time standards for work with machines 273

l. Plant and machine control 213
2. Restricted work 276
3. One man and one machine 278
4. Calculation of relaxation allowances 280
5. Unoccupied time allowance 283
6. Multiple machine work 286

20. Example of a time studY 291

21. Predetermined time standards 313

l. Definition 313
2. Origins 314
3. Advantages of PTS systems 315
4. Criticisms of PTS systems 315
5. Different forms of PTS systems 316
6. Use of PTS systems 3 19
7. Application of PTS sYstems 321

22. Standard data 339

l. Major considerations 339
2. Developing the standard data 340
3. Use of PTS systems to develop standard data 347
4. Use of computing equipment to calculate time standards 355

23. The use of time standards 365

l. Dehne the work covered by the time standards 365
2. The work specification 366
3. The standard unit ofwork 368
4. Production planning and the utilisation ofplant and labour 368
5. Estimating production costs 370
6. Standard costing and budgetary control 370
7. Incentive schemes 371
8. Organisation of the recording system associated with work measurement and
labour control 372

PART FOUR. FROM ANALYSIS TO SYNTHESIS:

NEW FORMS OF WORK ORGANISATION
24, Combined methods and tasks: new fonirs of work organisation 377
l. Method study and work measurement: basic tools for job design 317
2. Design of individual work roles 379
3. Design of group work in production 384
4. Designofproduct-orientedorganisations 396
x 5. Criteria of good work organisation: some concluding remarks 398
 CONTENTS

PART FIVE. APPENDICES

l. Glossary of terms used 405
2. Check-list of questions which may be of use in applying the questioning sequence
in method study 417
3. Example of tables used to calculate relaxation allowances 425
4, Conversion factors 435
5. Selected bibliography 439

FIGURES

l. Role of the management in co-ordinating the resources of an enterprise 1 I

2. How manufacturing time is made up 14
3. Work content due to the product and processes 15
4. Ineffective time due to shortcomings on the part of management and workers 19
5. How management techniques can reduce excess work content 23
6. How management techniques can reduce ineffective time 26
7. Work study 34
8. The four basic methods of controlling occupational hazards classified by decreasing
orderofeffectiveness 49
9. Mounting of general lighting units 57
10. Need for general lighting 56
I l. Maximum recommended spacing for industrial type units 56
12. Factors influencing the degree of glare produced by a given diffusing fitting (or a bare
fluorescent lamp unit) 58
13. Relative cost ofincandescent and fluorescent lighting 58
14. Recommended ranges of reflection factor for main interior surfaces 59
15. Distance at which the normal voice can be heard against background noise 60
16. Temporary hearing threshold shift in dB as a function of duration of exposure to wide-
band noise 6l
17. Limits of heat exposure 64
18. Ergonomic display design 70
19. Ergonomic design of controls 7l
20. Optimal use of physical effort 72
21. Method study 8l
22. Switch rotor assembly 9l
23. Outline process chart: switch rotor assembly 93
24. Some charting conventions 94
25. Flow process chart: engine stripping, cleaning and degreasing 97
26. Flow process chart-material type: engine stripping, cleaning and degreasing (original
method) 98
27. Flow diagram: engine stripping, cleaning and degreasing 103
28. Flow process chart-material type: engine stripping, cleaning and degreasing (improved
method) 105
29. Types oflayout 108
30. Example of various types of flow between work stations, including flow in a multi-storey
building I I I
31. Flow diagram: inspecting and marking incomirg parts (original method) I 13
32. Flow process chart: inspecting and marking incoming parts (original method) ll4
33. Flow diagram: inspecting and marking incoming parts (improved method) I 16
34. Flow process chart: inspecting and marking incoming parts (improved method) ll7
35. Developing the flow for a number ofproducts, using the cross chart I l9
36. Different types of material-handling equipment 122 XI
 37. Different possibilities of handling the same object 123
38. A string diagram 126
39. Simple movement study sheet 127
40. String diagram: storing tiles (original method) 130
41. String diagram: storing tiles (improved method) 13l
42. Flow diagram: serving dinners in a hospital ward 134
43. Flow process chart-man type: serving dinners in a hospital ward 135
44. Multiple activity chart: inspection of catalyst in a converter (original method) 137
45. activity chart: inspection of catalyst in a converter (improved method) 138
Multiple
46. activity chart-man and machine: finish mill casting (original.method) 140
Multiple
47. activity chart-man and machine: finish mill casting (improved method) l4l
Multiple
48. Combined team work and machine multiple activity chart: crushing bones (original
method 143
49. Crushing bones: layout ofworking area 144
50. Combined team work and machine multiple activity chart: crushing bones (improved
method) 147
51. Travel chart: movements of messenger in office 149
52. Simple study sheet 150
53. Travel chart: materials 152
54. Normal and maximum working areas 156
55. Assembling an electric meter 159
56. Two-handed process chart: cutting glass tubes (original method) 164
57. Two-handed process chart: cutting glass tubes (improved method) 166
58. Example of workplace layout (original method) 168
59. Example of workplace layout (improved method) 169
60. Right- and left-handed activity charts: assembly of power motor starting winding to
core l?0
61. Two-handed process charts: assembly of power motor starting winding to core
6L A simo chart 173
63. Standard practice sheet 179
64. A typical learning curve 182
65. Work measurement 192
66. Proportional distribution of"heads" ando'tails" 195
67. Distribution curve showing probabilities of combinations when large samples are
used 195
68. Curve of normal distribution 196
69. Nomogram for determining number of observations 200
?0. Example of a simple work sampling record sheet 203
71. Work sampling record sheet showing machine utilisation and distribution of idle
. time 203
72, Work sampling record sheet showing distribution of time on ten elements of work
performed by a group offour workers 203
73. Decimal-minute stop-watch 206
74, Time study boards 208
75. General-purpose time study top sheet 210
76. Continuation sheet for general-purpose time study (front) 2ll
77. Simple type of short cycle study form 212
78. Short cycle study form (front) 213
79. Short cycle study form (back) 214
80. Study summary sheet 216
81. Analysis of studies sheet 217
82. Distribution of times taken by workers to perform a given job 238
83. Effect of ineffective time on performance 242
84. Effect of a payment-by-results incentive on the time taken to perform an operation 243
85. Effect of extension on the time of an element 254
86. A graphical method of selecting basic time 258
Xf l 87. Cumulative average basic times for a constant element 262
 CONTENTS

88. Allowances 266

89. How the standard time for a simple manual job is made up 271
90. Explanatory diagram of machine time 275
91. Result of method study on milling operation 277
92. Milling operation: improved method 279
93. Four operations with machine elements 282
94. Machine interference 288
95. Card giving details of elements and break points 292
96. Sketch ofpart and ofworkplace layout 293
97. Time study top sheet 294
98. Time study continuation sheet 296
99. Second continuation sheet 298
100. Working sheet 300
l0l. Study summary sheet 302
102. Extract from the analysis ofstudies sheet 304
103. Calculation of relaxation allowance 306
104. Final calculation of relaxation allowance 308
105. Calculation and issue of the standard time 3 l0
106. Over-all cycle time 310
107. PTS data levels: basic motions 317
108. Base assembly 330
109. Base assembly workplace layout 33 I
10. MTM-2 analysis sheet, base assembly 332
11. Restricted walking 343
12. Base times for cross-cutting wood of varying width and thickness 345
13. Base curve for cross-cutting wood of2 cm thickness and ofvarying width 346
14. Factor curve for cross-cutting wood of varying width and thickness 347
15. Sequence ofelements 350
16. Basic elements of power press work 351
l7 . Power press work: example of TRANSPORI elements and distances 35 I
l18. Power press work: example of standard data determined by MTM-2 (tabular presenta-
tion) 352
I 19. Power press work: example of standard data determined by MTM-2 (algorithmic presen-
tation) 353
120. Power press work: standdrd data application form 354
l2l. A small hand-held programmable calculator showing the programme cards 356
122. A small programmable calculator providing a printed output 357
123. A small computing system which can be used for standard data calculations 358
124. Time study analysis programme 359
125. Time study analysis programme for element I 360
126. trime study analysis programme for element 2 361
127. Time study analysis programme for element 3 362
128. Time study analysis programme calculating various time factors and percentage
errors 363
129. Machine-paced line 385
130. Man-paced line 386
l3l. Automated process 387
132. Concentrated operation 388
133. Servicegroup 389
134. Construction group 389
135. Assembly of motor car engines 391
136. Line grouping and parallel grouping 392
137. Schematic diagram ofaflow-oriented group 394
138. Flow group for the manufacture ofpump axles 395
139. Layoutforaheatexchangerunit 398
140. Some examples of the building of buffer stock in manufacturing operations 399
l4l. Manufacture of electric motors 400 xlil
 CONTENTS

TABLES

l. Direct means of raising productivity 3 I

2. Properties ofvarious industrial floor surfaces 53
3. Recommended minimum values of illumination for various classes of visual task 55
4. Recommended maximum lighting intensity ratios 57
5. Calculation of noise level obtained by adding a new background noise source to a pre-
existing noise 63
6. Calculation of noise level obtained by removing a source of noise from the background
noise 63
7. Duration of continuous noise exposure which should not be exceeded to ensure the
prevention of occupational deafness amongst the majority of workers 63
8. Typical industrial problems and appropriate method study techniques 84
9. The most commonly used method study charts and diagrams 88
10. Classification of movements 157
11. Therbligs l7l
12. Proportional distribution of"heads" and "tails" 194
13. Table ofrandom numbers 199
14. Determining the sequence of time for random observations 201
15. Number of recommended cycles for time study 232
16. Specimen performance distribution 239
17 . Examples of various rates of working on the principal rating scales 248
18. Components of a basic PTS 314
19. Scope ofapplication ofdata 317
20. MTM-2 data card 32O
21. Fitting a nut and washer on a stud 328
22. Methods-Time Measurement application data in tmu 333
23. Restricted walking 342
24. Base times for cross-cutting wood of varying width and thickness 344
25. Standard data elements in light engineering and assembly work 348
26. Definition of terms, time study analysis programme 363
27. Minimum data required for work measurement and labour control records 373

XIV
 Part one
Productivity
andworkstudy
 Productivity
and the standard of living

1. The standard of living

By standard of living is meant the degree of material well-being available to
a person or class or community which is necessary for sustaining and enjoying life.
The standard of living of the representative person or family in the different
countries of the world varies greatly from country to country and even, within each
country, from community to community. Today, in spite of the immense efforts that
have been made, both at the national and at the international levels, a significant
proportion of mankind continues to eke out an existence in conditions of acute
poverty. In too many parts of the world the ordinary man is still hardly able to satisfy
his basic needs.

2. Requirements for a minimum satisfactory

standard of living
What are the basic needs that must be met in order to attain a minimum de-
cent standard of living?
Principally, they are-
u FooD
enough food every day to replace the energy used in living and working;
E CLOTHING
enough clothes to permit bodily cleanliness and afford protection from the
weather;
t] SHELTER
shelter which is of a standard high enough to give protection under healthy
conditions and which is equipped with certain household equipment and
furniture;
t] SECURITY
security against robbery or violence, against loss of the opportunity to
work, against poverty due to illness or old age; and
N ESSENTIAL SERVICES
such as safe drinking-water, sanitation, medical care, public transport, and
educational and cultural facilities that would enable every man, woman and
child to develop to the full his or her talent and abilities.
 Food, clothing and shelter are generally things which a man has to obtain
for himself. In order to have them he must pay for them, either in money or work.
Security and essential services are generally matters for governments and other
public authorities. The services of public authorities have to be paid for, generally by
individual citizens, so each man must earn enough to pay his contribution to the com-
mon services as well as to support himself and his family.
Each nation or community must, in the long run, be self-supporting. The
standard of living achieved will be that which the representative citizen is able to
achieve through his own efforts and those of all his fellow citizens.
The greater the amount of goods and services produced in any community,
the higher its average standard of living will be.
There are two main ways of increasing the amount of goods and services
produced. One is to increase employment; the other is to increase productivity.
If in any community there are men and women who are able to work and
who want work but who are unable to find work, or who are able to find only part-
time work, the output of goods and services can be increased if full-time productive
work can be provided for them, i.e. if employment can be increased. Whenever there is
unemployment or underemploymen! efforts to increase employment are very impor-
tant and should go hand in hand with efforts to increase the productivity of those who
are already employed. But it is with the latter task that we are here concerned.
We can have-
tr more and cheaper food by increasing the productivity of agriculture;
tr more and cheaper clothing and shelter by increasing the productivity of in-
dustry;
tr more security and essential services by increasing all productivity and earn-
ing power, leaving more from which to pay for them.

3. What is productivityT
Productivity may be defined as follows:

This definition applies in an enterpriseo an industry or an economy as a

whole.
Put in simpler terms, productivity, in the sense in which the word is used
here, is nothing more than the arithmetical ratio between the amount produced and
the amount of any resources used in the course of production. These resources may
be-
t] LAND
D MATERIALS
tr PLANT, MACHINES AND TOOLS
tr THE SERVICES OF MEN
or, as is generally the case, a combination of all four.

We may find that the productivity of labour, land, materials or machines in

any establishment, industry or country has increased, but the bare fact does not in
itself tell us anything about the reasons why it has increased. An increase in the
productivity of labour, for example, may be due to better planning of the work on the
part of the management or to the installation of new machinery. An increase in the
productivity of materials may be due to greater skill on the part of workers, to
improved designs, and so on.

Examples of each type of productivity may make its meaning clearer.

tr PRODUCTIVITY OF LAND
If, by using better seed, better methods of cultivation and more fertiliser, the
yield of corn from a particular hectare ofland can be increased from 2 quin-
tals to 3 quintals, the productivity of that land, in the agricultural sense, has
been increased by 50 per cent. The productivity of land used for industrial
purposes may be said to have been increased if the output of goods or ser-
vices within that area of land is increased by whatever means.
tr PRODUCTIVITY OF MATERIALS
If a skilful tailor is able to cut 11 suits from a bale of cloth from which an
unskilful tailor can only cut ten, in the hands of the skilful tailor the bale
was used with l0 per cent greater productivity.
tr PRODUCTIVITY OF MACHINES
If a machine tool has been producing 100 pieces per working day and
through'the use of improved cutting tools its output in the same time is in-
creased to 120 pieces, the productivity of that machine has been increased
by 20 per cent.
I] PRODUCTIVITY OF MEN
Ifa potter has been producing 30 plates an hour and improved methods of
work enable him to produce 40 plates an hour, the productivity of that man
has increasedby 33r/t per cent.

In each of these deliberately simple examples output-or production-has

also increased, and in each case by exactly the same percentage as the productivity.
But an increase in production does not by itself indicate an increase in productivity. If
the input of resources goes up in direct proportion to the increase in output, the
productivity will stay the same. And if input increases by a greater percentage than
output, higher production will be being achieved at the expense of a reduction in
productivity.
In short, higher productivity means that more is produced with the same
expenditure of resources, i.e. at the same cost in terms of land, materials, machine
time or labour; or alternatively that the same amount is produced at less cost in terms
of land, materials, machine time or labour used up, thus releasing some of these
resources for the production of other things.

4. Relationship between increased productivity and higher

standards of living
We can now see more clearly how higher productivity can contribute to a
higher standard of living. If more is produced at the same cost, or the same amount is
produced at less cost, there is a gain to the community as a whole, which can be used
by members of the community to acquire more and better goods and services and to
improve their standard of living.

5. Productivity in industry
The problems of raising the productivity of the land and of livestock are
matters for the agricultural expert. This book is not concerned with them. It is mainly
concerned with raising productivity in industry, especially manufacturing industry.
The techniques of work study described in it can, however, be used with success
wherever work is done-in factories or offrces, in shops or public services, and even
on farms.
Cloth for clothes, many parts of houses, sanitary ware, drainage and
waterworks equipmen! drugs and medical supplies, equipment for hospitals and for
defence are all the products of industry. So are many things necessary for living above
the level of bare existence. Household utensils, furniture, lamps and stoves generally
have to be made in workshops, large and small. Many of the goods necessary for run-
ning a modern community are too complex and too heavy to be made by cottage or
small-scale industry. Railway engines and carriages, motor trucks, electric generators,
telephones, computer equipmen! all require expensive machines to make them, special
equipment to handle them and an army of workers of many different skills. The
greater the productivity of the establishments making these things, the greater are the
opportunities of producing them abundantly and cheaply in quantities and at prices
which will meet the requirements of every family in the community.
The factors affecting the productivity of each organisation are many, and
no one factor is independent of others. The importance to be given to the productivity
of each of the resources-land, materials, machines or men-depends on the
enterprise, the industry and possibly the country. In industries where labour costs are
low compared with material costs, or compared with the capital invested in plant and
equipment (as in heavy chemical plants, power stations or paper mills), better use of
materials or plant may give the greatest scope for cost reduction. In countries where
capital and skill are short, while unskilled labour is plentiful and poorly paid, it is es-
pecially important that higher productivity should be looked for by increasing the out-
put per machine or piece of plant or per skilled worker. It often pays to increase the
number of unskilled workers if by doing so an expensive machine or a group of skilled
craftsmen are enabled to increase output. Most practical managers know this, but
 PRODUCTIVITY AND THE STANDARD OF LIVING

many people have been misled into thinking of productivity exclusively as the produc-
tivity of labour, mainly because labour productivity usually forms the basis for
published statistics on the subject. In this book the problem of raising productivity will
be treated as one of making the best possible use of all the available resources, and at-
tention will constantly be drawn to cases where the productivity of materials or plant
is increased.

6. The background of productivity

To achieve the greatest increases in productivi$, action must be taken by
all sections of the community: governments, employers and workers.
Governments can create conditions favourable to the efforts of employers
and workers to raise productivity. For these it is necessary, among other things-

to have balanced programmes of economic development;

to take the steps necessary to maintain employment;
to try to make opportunities for employment for those who are unemployed
or underemployed, and for any who may become redundant as a result of
productivity improvement in individual plants.
This is especially important in developing countries where unemployment is a big
problem.
Employers and workers also have vital parts to play. The main respon-
sibility for raising productivity in an individual enterprise rests with the management.
Only the management can introduce and create a favourable climate for a produc-
tivity programme and obtain the co-operation of the workers which is essential for
real success, though this requires the goodwill of the workers too. Trade unions can
actively encourage their members to give such co-operation when they are satisfied
that the programme is in the interests of the workers, as well as of the country as a
whole.

7. The attitude of the workers

One of the greatest difliculties in obtaining the active co-operation of the
workers is the fear that raising productivity will lead to unemployment. Workers fear
that they will work themselves out of their jobs. This fear is greatest when unemploy-
ment already exists and a worker who loses his job will find it hard to get another.
Even in the economically developed countries where employment has for years been
at a very high level, this fear is very real to those who have already experienced un-
employment.
Since this is so, unless workers are assured of adequate assistance in
meeting their problems, they may resist any steps which they fear, rightly or wrongly,
will make them redundant, even though their period of unemployment may only be a
short one, while they are changing jobs.
Even with written guarantees, steps taken to raise productivity will probably
meet with resistance. This resistance can generally be reduced to a minimum if
everybody concerned understands the nature of and reason for each step taken and
 DABD OF LIVING

has some say in its implementation. Workers' representatives should be trained in the
.techniques of increasing productivity so that they will be able both to explain them to
their fellow workers and to use their knowledge to ensure that no steps are taken
which are directly harmful to them. Many of the safeguards mentioned above can best
be implemented through joint productivity committees and works councils.
 in the individual enterprise

It was said in Chapter 1 that there were a number of factors affecting the
productivity of an enterprise. Some of these, such as the general level of demand for
goods, taxation policy, interest rates and the availability of raw materials, suitable
equipment or skilled labour, are outside and beyond the control of any one employer.
Certain other factors can be controlled from inside the enterprise, and it is these that
we are now going to discuss.

1. Resources at the disposal of an enterprise.

Productivity was defined as oothe ratio of output to input" in an enterprise,
an industry or an economy as a whole.
The productivity of a certain set of resources (input) is therefore the amount
of goods or services (output) which is produced from them. What are the resources at
the disposal of a manufacturing company? I They are-

tr LAND AND BUILDINGS

Land in a convenient location on which to erect the buildings and other
facilities necessary for the operations of the enterprise, and the buildings
erected on it.
! MATERIALS
Materials that can be converted into products to be sold. They include fuel,
chemicals for use in the processes of manufacture, and packing materials.
tr MACHINES
Plant, equipment and tools necessary to carry out operations of manufac-
ture and the handling and transport of materials; heating, ventilating and
power plant; office equipment and furniture.
tr MANPOWER
Men and women to perform the manufacturing operations; to plan and con-
trol; to do clerical work; to design and to research; to buy and sell.

rThis discussion of productivity applies equally to non-manufacturing helds. The proper use of
manpower, equipment and other resources is just as important in running a railway, an airline or municipal
services as in running a factory.
 PRODUCTIVITY IN THE INDIVIDUAL ENTERPRISE

The use which is made of all these resources combined determines the
productivity of the enterprise.

The resources consist of "real" things and services. When they are used up
in the process of production, "real" costs are therefore incurred. Their cost may also
be measured in terms of money. Since higher productivity means more output from
the same resources, it also means lower money costs and higher net money returns per
unit of output.

2. The task of the management

Who is responsible for making sure that the best use is made of all these
resources? Who is responsible for seeing that they are combined in such as way as to
achieve the greatest productivity? The management of the enterprise.
In any concern larger than a one-man business (and to some extent even in
a one-man business) the work of balancing the use of one resource against another
and of co-ordinating the efforts of everyone in the organisation to achieve the best
results is the job of the management. If the management fails to do what is necessary,
the enterprise will fail in the end. In such a case the four resources become uncoordi-
nated-like the efforts of four horses without a driver. The enterprise, like a driverless
coach, moves forward jerkily, now held up for lack of material, now for lack of equip-
ment because machines are badly chosen and even more badly maintained, or
because employees are unable or unwilling to do their best. The key position of the
management may be shown by a diagram (figure 1).
This is not the place to discuss the activities (listed in the figure) by which
the management achieves the transformation of the resources at its disposal into
finished products. (The titles of some textbooks on management will be found in the
book list at the end of this volume (Appendix 5)). It may not be out of place, however,
to say something about the term "motivate".
To oomotivate" means to provide a motive or reason for doing something.
Used in the context of management it means, in effect, to make people want to do
something. It is of little use the management carrying out the other activities of getting
facts, planning, and so on, if the people who are supposed to carry out the plans do
not want to do so, although they may have to. Coercion is no substitute for voluntary
action. It is one of the tasks of the management, and perhaps its most dfficult task, to
make people want to co-operate; the management can only succeed fully by enlisting
the willing and active participation of workers at all levels.

3. The productivity of materials

The relative importance of each of the resources mentioned above and
shown in figure I varies according to the nature of the enterprise, the country in which
it is operating, the availability and cost of each type of resource and the type of
product and process. There are many industries in which the cost of raw material
10 represents 60 per cent or more of the cost of the finished product, the balance of 40
 PRODUCTIVITY IN THE INDIVIDUAL ENTERPRISE

Figure I . Role of the management in co-ordinating the resources of an enterprise

PLANT
MACHINES
EQUIPMENT

THE
MANAGEMENT

AINSTHE FACTS
PLANS
DIRECTS
CO.ORDINATES
CONTROLS
MOT!VATES
in order to
produce

GOODS AND SERVICES

o DUC
11
 PRODUCTIVITY IN THE INDIVIDUAL ENTERPRISE

per cent being divided between labour and overhead costs. Many countries have to
import a very large proportion of their basic raw materials and pay for them in scarce
foreign currencies. Under either of these conditions the productivity of materials
becomes a key factor in economic production or operation; it is likely to be far more
important than the productivity of land or labour or even plant and machinery.
Although the technique of work study, with which this book is concerned, deals
primarily with improving the utilisation of plant and of the services of labour, it can
frequently contribute to savings in materials, either directly or indirectly, as in saving
the erection of buildings through the better utilisation of existing space. In general,
however, savings in materials, direct or indirect" are effected in the following ways:

tr at the design stage or time of specification-

by ensuring that the design is such that the product can be manufactured
with the least possible use of materials, especially when they are scarce or
dear;
by ensuring that plant and equipment specified for purchase is the most
economical possible in terms of materials consumed in its operation (e.g.
fuel) for a given level of performance.

tr at the process or operation stage-

by ensuring that the process used is the right one;
by ensuring that it is being operated correctly;
by ensuring that operatives are properly trained and motivated so that they
will not turn out faulty work which has to be rejected, leading to loss of
material;
by ensuring proper handling and storage at all stages from raw materials to
finished products, first eliminating all unnecessary handling and movement;
and
by proper packaging to avoid damage in transit to the customer.

The question of material saving is so important to many countries that a

separate volume would be needed to discuss it.

4. The productivity of land, buildings, machines

and manpower
The effective utilisation or maximum productivity of land and buildings is
an important source of cost reduction, especially when an enterprise is expanding and
needs increased working space. Any reduction in the original specification which can
be effected before land is purchased or buildings erected represents a saving in capital
outlay (or rental) of land and buildings, a saving in materials (particularly fittings,
which may have to be imported) and a probable saving in taxes as well as a saving in
future maintenance costs. Examples of space saving and the techniques of work study
12 employed to achieve them will be found in Chapters 9 and 10.
 IN THE INDIVIDUAL ENTEHPRISE

We now come to consider the productivity of plant, machinery and equip-

ment and of the services of men and women. Let us take another look at the nature of
productivity, which in simple terms was described as the "arithmetical ratio between
the amount produced and the amount of any resources used in the course ofproduc-
tion". To do this we have to start thinking in terms of time, since it is the output of
good production from a machine or from a worker in a given time which is used in
calculating productivity. Productivity is frequently measured as the output of goods or
services in a given number of "man-hours" or "machine-hours".

5. How the totaltime of a job is made up

tr A man-hour is the labour of one man for one hour.
tr A machine-hour is the running of a machine or piece of plant for one hour.
The time taken by a man or a machine to carry out an operation or to
produce a given quantity of product may be considered as made up in the following
manner, which is illustrated in figure 2.
There is first-
the basic work content of the product or operationl
Work content means, of course, the amount of work oocontained in" a given
product or process measured in man-hours or machine-hours.2 The basic work con-
tent is the time the product would take to manufacture or the operation to perform if
the design or specification were perfect, if the process or method of manufacture or
operation were perfectly carried out, and if there were no loss of working time from
any cause whatsoever during the period of the operation (other than legitimate rest
pauses permitted to the operative). The basic work content is the irreducible minimum
time theoretically required to produce one unit of output.
This is obviously a perfect condition which never occurs in practice,
although it may sometimes be approached, especially in processing industries. In
general, however, actual operation times are far in excess of it on account of-
excess work content

The work content is increased by the following:

A. Work content added by defects in the design or
specification of the product
This occurs primarily in manufacturing industries, but the equivalent in
service industries such as transport might be the specification of a bus service which
demands operation in a way that causes unnecessary additional transit time. This
additional work content is the time taken over and above the time of the basic work
content due to features inherent in the product which could be eliminated (see
figure 3).
rThe words "or operation" are added throughout because this picture applies equally to non-manu-
facturing industries such as transport operation or retail selling.
2
This definition differs slightly from that given in the B. S. Glossary (British Standards Institution:
Glossary of terms used in work study (London, I 969). See note at the bottom of figure 2, 13
 PRODUCTIVITY IN THE INOIVIDUAL ENTERPFISE

Figure 2. How manufacturing time is made up

Basic
Work Gontent
of
product
and/or
operation

Total
Work
Gontent Work Content
Added
by defects in
Total design or specification
oI product
Time

of Work Content
Added
Operation by
inefficient methods
under of
manufacture or oPeration
Existing
Conditions

lneffective Time
due to
shortcomings
of
Tota! the management

lneffective

l
Time

fL lneffective Time
within
ir) the control
of
the worker

Note: ln the B.S. G/ossary the terms "work content" and "ineffective timg" ars accorded prsciso technical meanings which
differ slightly frcm thos used hsre. Tho G/ossary definitions ars intonded for uso in applying work measuromsnt techniques, and are not
strictly relevant to ths prsssnt discusion. ln this chapter and the nsxt, "work content" and "in€ffective tims" are ussd with their ordinary
common msanings, as defined in tho text.

14
 PBODUCTIVITY IN THE INDIVIDUAL ENTERPRISE

Figure 3. Work content due to the product and processes

I
Total
Work
Content
of the
prevents use of
-r
most economic processes
Product
Lack of Standardisation
prevents use oI
Work Content
Total high-production processes Added
by defects in design
I
Work A.3. lncorrect or.specification of
Ouality Standards the product
cause unnecessary work
Gontent
I

l_
B.2. Process Not Operated
Correctly
or in bad condilions
1
Work Content
Added
by inefficient methods
of manufacture
or operation

I
(see figure 4)

-fl_
15
 PFODUCTIVIry IN THE INDIVID

B. Work content added by inefEcient methods of

production or operation
This is the time taken over and above the basic work content plus A, due to
inefficiencies inherent in the process or method of manufacture or operation (see
figure 3).
r

The basic work content assumes uninterrupted working. In practice,

however, uninterrupted working is exceptional, even in very well run organisations.
AII interruptions which cause the worker or machine or both to cease producing or
carrying out the operations on which they are supposed to be engaged, whatever may
be the cause, must be regarded as ineffective time (see note at bottom of figure 2)
because no work effective towards completing the operation in hand is being done
during the period of the interruption. Ineffective time reduces productivity by adding
to the duration of the operation. Apart from interruptions from sources outside the
control of anyone in the organisation, such as a power breakdown or a sudden rain-
storm, ineffective time may be due to two causes-

C. Ineffective time due to shortcomings on

the part of the management
Time during which man or machine or both are idle because the manage-
ment has failed to plan, direct, co-ordinate or control efficiently (see figure 4).

D. Ineffective time within the control of the worker

Time during which man or machine or both are idle for reasons within the
control of the worker himself (see figure 4).
The relative sizes of the different sections of flrgure 2 have no special
significance and will vary from operation to operation and from undertaking to under-
taking even for the same operation. The application of work study has often made it
possible to reduce operation times to one-half or even one-third of their original values
without by any means exhausting the possibilities of further reduction.
Let us now examine each of these sets of causes of excess time (excess work
content or ineffective time) in turn and look in detail at some of the reasons for them.

6. Factors tending to reduce productivity

A. Work content added due to the product (figure 3)
How can features of the product affect the work content of a given opera-
tion?
There are several ways in which this can happen-
(l) The product and its components may be so designed that it is impossible to use
the most economical processes or methods of manufacture. This applies especially
16 to the metalworking industries and most particularly where large-scale production
 PRODUCTIVITY IN THE INDIVIDUAL ENTERPRISE

is undertaken. Components may not be designed to take advantage of high-

production machinery (example: a sheet-metal part may be so designed that it has
to be cut out and riveted or welded instead of being pressed in one piece).
(2) Excessive variety of products or lack of standardisation of components may mean
that batches of work have to be small and cannot be put on special-purpose high-
production machines but have to be done on slower general-purpose machines
(see also C 2).

(3) Incorrect quality standards, whether too high or too low, may increase work con-
tent. In engineering practice close tolerances, requiring extra machining, are often
put on dimensions where they are quite unnecessary. There will thus be more re-
jects and a corresponding waste of material. On the other hand, material of too
low a quality may make it difficult to work to the finish required or may make ad-
ditional preparation of the product, such as cleaning, necessary to make it usable.
The quality of material becomes especially important in connection with automa-
tion.
(4) The components of a product may be so designed that an excessive amount of
material has to be removed to bring them to their final shape. This increases the
work content of the job and wastes material as well (example: shafts with very
large and very small diameters designed in one piece).
The first step towards raising productivity and lowering the cost of the
product is therefore to eliminate as far as possible all features in its design and
specification that are likely to cause excess work content, including non-standard
products demanded by customers where a standard product would serve as well.

B. Work content added due to the process or method (figure 3)

How can ineffrcient operation of the process or ineffrcient methods of
production or operation affect the work content of the job?

(1) If the wrong type or size of machine is used, one which has alower outputthan
the correct one (examples: small capstan work put on a turret or centre lathe; nar-
row cloth put on too wide a loom).
(2) If the process is not operating properly, that is at the correct feed, speed, rate of
flow, temperature, density of solution or whatever conditions govern its operation,
or if the plant or machine is in bad condition.
(3) If the wrong hand tools are used.
(4) If the layout of the factory, shop or workplace causes wasted movement, time or
effort.
(5) If the working methods of the operative cause wasted movement, time or effort.
It should be noted that the idea of work content in terms of time is based on
the assumption of operation at a steady average working pace. The additional time
taken as a result of a slowing down of the working pace might be considered as
ineffective time, but this is unimportant for the present discussion.
Optimum productivity from the process will be reached only if it is operated
with the least waste of movement, time and effort and under the most efficient condi- 17
 PBODUCTIVITY IN THE INDIVIDUAL ENTERPRISE

tions. All features which would cause the worker to make unnecessary movements,
whether around the shop or at the workplace, should be eliminated.
It will be seen that all the items in the excess work content may be attributed
to deficiencies on the part of the management. This is true even of bad working
methods on the part of the operatives if these are due to failure by the management to
see that operatives are properly trained and supervised.

C. Ineffective time due to the management (figure 4)

Let us now consider the ineffective time in the manufacturing or operating
cycle. How can shortcomings on the part of the management affect it?

(l) By a marketing policy which demands an unnecessarily large number of types of

product. This causes short runs of each type, and machines are idle while they are
being changed over to manufacture different products. The workers do not have
the opportunity to acquire skill and speed in any one operation.
(2) BV failing to standardise component parts as far as possible between products or
within product. This has the same effect-that is, short runs and idle time.r
(3) By failing to ensure that designs are properly developed or that customers' re-
quirements are met from the beginning. This results in changes of design, causing
stoppages of work and loss of machine- and man-hours as well as waste of
material.
(4) By failing to plan the flow of work and of orders, with the result that one order
does not follow immediately on another and plant and labour are not continuously
employed.
(5) By failing to ensure a supply of raw materials, tools and other equipment neces-
sary to do the work, so that plant and labour are kept waiting.
(6) BV failing to maintain plant and machines properly. This leads to stoppages due
to machine breakdowns.
(7) By allowing plant and machinery to be operated in bad condition so that work is
scrapped or returned for rectifircation and has to be done again. Time spent in
rework is ineffective.
(8) By failing to provide working conditions in which the operative can work steadily.
(9) BV failing to take proper precautions for the safety of workers. This causes lost
time due to accidents.

D. Ineffective time within the control of the worker (figure 4)

Finally, how can action (or inaction) on the part of the workers themselves
cause ineffective time?

(1) BV workers taking time off work without good cause: by lateness, by failing to
start work immediately after clocking in, by idling at work or by deliberately
working slowly.

I Like "work content and ineffective time", the term "idle time" is given a special meaning in the B.S.
I 8 Glossary.The Glossarv meaning is not relevant here.
 PRODUCTIVITY IN THE INDIVIOUAL ENTERPRISE

Figure 4. lneffective time due to shortcomings on the part

l
of management and workers

II I
Work Content

r
Time C.1. Excoasive
Product Variety
adds idle time due to shon runs
+
of I
C.2. Lack of
Standardisation I
Operation adds idle lime due to short runs

Total within C.3. Dsaign Changes

I

add ineflective time

Time the due lo stoppages and rework
I

of C.4. Bad Planning I

Control of work and orders adds
idle time of men and machines
Operation tneffective Time
of the due to
C. 5. Lack of Raw Materials
Under due to bad planning adds shortcomings of
Management idle time ot men and machines the
Existing management
C.6. Plant Broakdowns
add
Conditions idle lime oI men and machines
I
C.7. Plant in Bad Condition
adds ineflective time I
l due to scrap and rework
I

I
C.8. Bad Working Conditions
add inelfective time through
I Iorcing workers to rest I

C.9. Accidents I
add inefrective time
through stoppages and absence I

t
D.1. Absence, Latensss
and ldlenoas
add inellective time
t
lneffective Time
D. 2. Caroless Workmenahip
within
adds ineflective time
due to scrap and rework the control of
the worker
D.3. Accidents

_t
add ineffective time
through stoppages and absence

I/oter "ldle tims" is used here in the ordinary sense of the term, not that defined in the B.S. G/ossary.

19
 JAL ENTERPRISE

(2) BV careless workmanship causing scrap or making it necessary for work to be

done again. Work which has to be done again means wasted time, and scrap
means wasted materials.
(3) BV failing to observe safety regulations and by having or causing accidents
through carelessness.
In general, far more ineffective time is due to management shortcomings
than to causes within the control of workers. In many industries the individual worker
has very little control over the conditions under which he is required to operate. This is
especially true of industries using a lot of plant and machinery and making a complex
product (see next chapter).
If all the factors enumerated under the four headings above can be
eliminated (the ideal situation which, of course, never occurs in real life), the minimum
time for the production of a given output and hence the maximum productivity is
achieved.

20
 ShapEr3
Reducing work content
and ineffective time

How can maximum productivity with existing resources be approached? In

every case it must be as a result of action by the management, with the co-operation
of the workers, together with, in some cases, extra technical or scientific knowledge.
This action should aim at reducing work content and cutting down on ineffective
time.

1. Reducing work content due to the product

If the design of the product is such that it is not possible to use the most
economical processes and methods of manufacture, this is usually because designers
are not familiar enough with these processes; it is especially liable to occur in the
metalworking, furniture and garment industries. The weakness can be overcome if the
design and production staffs work closely together from the beginning. If the product
is to be produced in large quantities or is one of a range of similar products produced
by the firm, improvements to make it easier to produce can be introduced at the
product development stage, when production staff can examine the components and
assemblies and call for changes before money has been spent on production tools and
equipment. At this time also, alterations in design can be made to avoid making it
necessary to remove too much material, and tests can be made in running the product
to ensure that it meets the technical specifications demanded. The equivalent to the
product development stage in the chemical and allied industries is the pilot planL In
transport (a non-manufacturing industry) the equivalent is the experimental service or
the proving flights which are carried out on airliners.
Specialisation and standardisation, which are discussed more fully in sec-
tion 4, are the techniques by which the variety of products or components can be
reduced and batch sizes increased so that use can be made of high-production pro-
cesses.

If quality standards are higher than are necessary for the efficient function-
ing of the product, the time taken to manufacture it will generally be greater because
of the extra care lequired; unnecessary rejects will also result. Customers sometimes
make demands foh tolerances or finishes of higher standards than necessary. On the
other hand, neglecting quality, especially the quality of materials purchased, may
prolong the time of manufacture because the materials may be difficult to work with.
Quality standards, on the other hand, must be geared to requirements. They should be
set neither too high nor too low, and they should be consistent. The management must 21
 be sure of the requirements of the market and of the customBr, and of the technical re-
quirements of the product itself. The first two may be established by market research
and consumer research. Where the quality level is set by technical considerations,
product research may be necessary to establish what it should be. Ensuring that
quality requirements are met in the production shops is the concern of the quality con-
trol or inspection function. The men who perform this function must be properly in-
formed of the quality level required and should be able to advise the designers which
quality standards can safely be altered to achieve higher productivity.
Figure 5 shows the effect of applying these techniques to reduce the work
content of thb product. (In the figures in this chapter, as in the last, no special
significance attaches to the sizes ofthe various rectangles; the figures are for illustra-
tiuo- only). Yet another technique, which is used also to reduce the work content due to
the process or method, is value analysis, the systematised investigation of the product
and its manufacture to reduce cost and improve value.

2. Reducing work content due to the process or method

If the proper steps are taken to remove features that cause unnecessary
work in the product before production actually starts, effort can be concentrated on
reducing the work content ofthe process.
In industries which have developed their practice from engineering, it is
usual nowadays for the process planning function to be responsible for specifying the
machines on which the product and its components shall be made, the types of tools
necessary and the speeds, feeds and other conditions under which the machines shall
be run. tn the chemical industries these conditions are usually laid down by the scien-
tists in the research department. In all types of manufacturing industry it may be
necessary to carry out process research in order to discover the best manufacturing
techniques. Proper maintenance will ensure that plant and machinery is operating
properly and will prolong its life, so reducing capital expenditure. Process planning
combined with method study will ensure the selection of the most suitable tools for the
operative.
The layout of the factory, shop or workplace and the working methods of
the operative are the task of method study, one of the two branches of work study
which form the main subject of this book. As method study will be discussed in detail
in Chapters 7 to 12 nothing more will be said about it here. Coupled with method
study is operator training as an aid to improving the working methods of the
operative.
Figure 5 shows the effect of these techniques when applied to reducing the
work content ofthe process.

3. Reducing ineffective time due to the management

The responsibility of the management for the achievement of high produc-
tivity is always great, especially in the reduction of ineffective time. Ineffective time
22 can be a source of great loss even where working methods are very good.
 REDUCING WORK CONTENT ANO INEFFECTIVE TIME

Figure 5. How management techniques can reduce excess work content

TOTAL

-L A.1. Product Development

and Value Analysis

&- J reduce excess work contenl

due to design defects

I m
A.2. Specialisation and Stand-
ardisation enable high-pro-
duction processes to be used
o I- ru A.3. Market, Consumer and
Product Research ensure
LU
F Ercess
L J correct quality standards
A.4. Product Devolopment
and Value Analysis
Work Content U n reduce work content due to

totally
eliminated
r
U
-I excess material
8.1. Process Planning
ensures selection of

=
if all
techniques
perfectly
FI
J correct machines
8.2. Process Planning and
applied
T il Research ensure correct
operation of processes

LU f a B.3. Procoss Planning and

Method Study ensure
I
L { correct selection of tools

I
Fl
I 8.4. Method'Study reduces work

r
tsi content due to bad layout

t
L I 8.5. Method Study and
Ll (rperator Training
reduce work content due
to bad working methods

TIME t,

I
!neffective
Time
(to be eliminated)

l_ ^J

23
 REDUCING WORK CONTENT A]

The reduction of ineffective time starts with the policy of the directors con-
cerning the markets which the firm shall try to serve (marketing policy). Shall the firm
specialise in a small number of products made in large quantities at the lowest possible
price and sell them cheaply, or shall it try to meet the special requirements of every
customer? The level of productivity that can be achieved will depend on the answer to
this question. If many different types of product are made, this means that machines
have to be stopped in order to change one type to another; workers are unable to gain
speed on work because they never have enough practice on any onejob.
This decision must be taken with a full understanding of its effects. Unfor-
tunately, in many companies the range and variety of product grows unnoticed
because of attempts to increase sales by meeting every special demand for variations,
most of which may well be unnecessary. Specialisation, therefore, can be an important
step towards eliminating ineffective time.
Standardisation of components will also reduce ineffective time. It is often
possible to standardise most of the components in a range of models of the same type
of product; this gives longer runs and reduces the time spent in changing over
machines.
Much ineffective time is caused by failing to ensure that the product is func-
tioning correctly or meets the requirements of the customers before it is put into full
production. Consequently, parts have to be redesigned or modiflred, and these
modifications mean wasted time, material and money. Every time a batch of parts has
to be remade there is ineffective time. The function of product development, men-
tioned in section 2 above, is to make these modifications before work begins in the
production shops.
The planning of proper programmes of work so that plant and workers are
kept supplied with jobs without having to wait is known as production planning, and
the control of that programme to ensure that it is being carried out is production con-
trol. A proper programme can be worked out and applied only on the basis of sound
standards of performance. These are set by the use of work measuretnent, the second
technique of work study. The importance of knowing accurately how long each job
may be expected to take is discussed at length in the chapters on work measurement
(Chapters l3 to 23).
Workers and machines may be made idle because materials or tools are not
ready for them when they are needed. Material control ensures that these require-
ments are foreseen and fulfilled in time, and at the same time that materials are bought
as economically as possible and that the stocks maintained are not excessive. In this
way the cost of holding stocks of materials is kept down.
Machines and plant which break down cause idleness, reduce productivity
and increase manufacturing costs. Breakdowns can be reduced by proper
maintenance. Plant and machinery in bad condition will turn out bad work, some of
which may have to be scrapped. This takes time, which must be regarded as ineffec-
tive time.
If the management fails to provide good working conditions, ineffective time
will be increased because workers will have to take more rest to overcome fatigue or
24 the effects of heat, fumes, cold or bad lighting. If the management fails to take the
 REDUCING WORK CONTENT AND INEFFECTIVE TIME

proper precautions for the safety of the workers, ineffective time will be increased
owing to loss of time through accidents and absenteeism.
It will be seen that, even where the work content of the product and process
has been reduced as much as possible under the existing conditions, it is still possible
for there to be a great deal of waste simply through failure to use time properly. Much
of the responsibility for this rests with the management.
Figure 6 shows how this excess time can be reduced by applying the
management techniques mentioned.

4. Reducing ineffective time within the control

of the worker
Whether the available time is fully used also depends on the workers. It is
widely believed that someone doing a manual job can work faster or slower according
to his choice. This is true only up to a certain point. Most people who have been doing
a job for a long time have a certain pace at which they work best and at which they
will normally work. Usually, a worker trained at and accustomed to his job cannot ac-
tually work much faster, except for short periods, and equally feels uncomfortable if
forced to work more slowly than his natural pace. Any attempt to speed up the rate of
working, except by proper training, will tend to increase the number of errors made.
The worker can save time mainly by reducing the amount of time when he is not
working, that is, when he is talking to his fellow workers, having a smoke, waiting to
clock off,late or absent.
In order to reduce this ineffective time he must be made to want to reduce it,
and it is the business of the management to create the conditions that will make him
want to get on with his work.
First, bad working conditions make it diffrcult to work for long stretches at
a time without frequent periods of rest and produce an attitude of mind in the worker
which makes him feel that he does not want to try.
Second, if the worker feels that he is simply looked upon by the manage-
ment as a tool of production without any regard being paid to his feelings as a human
being, he will not want to make a greater effort than he has to in order to keep his job.
Third, if the worker does not know what he is doing or why he is doing it, if
he knows nothing of the work of the firm as a whole, he can hardly be expected to give
of his best.
Fourth, if the worker feels that he does not receive justice from the manage-
ment, the feeling of grievance will hinder him from doing his best.
The willingness of the worker to get on with the job and reduce this ineffec-
tive time depends very much on the personnel policy of the management and its at-
titude to him. Personnel policy involves the whole relationship between the manage-
ment and employees; if this relationship is not a good one, it is very difficult to make
any management techniques work satisfactorily. To create the right conditions for
good relationships is part of the art of management. A sound personnel policy in-
cludes the training of managers and supervisors of all ranks in proper attitudes to and
relations with the workers. 25
 REDUCING WORK CONTENT AND INEFFECTIVE TIME

Figure 6, How management techniques can reduce ineffective time

Total
Time
if Ail
Techniques
Perfectly
I :
Basic
Work
Contenl
.-r,"ts--
Applied

G.l. Marketing and SPecialisa-

tion reduce idle time due

L to product variety

C.2. Standardasation reduces

E
r
idle time due to short runs

I C.3. Product Development

reduces ineffective time due
n_ J to changes in design
C.4. Production Contro! based
on Work Measurement
L reduces idle time due to bad

V I planning
C.5. Material Control reduces
idle time due to lack of raw

lnelfective L J materials

Time
Totally t C.6. Maintenance reduces idle
time of men and machines
Eliminated
if Ail
Techniques r T
due to breakdowns

c.7. Maintenance reduces

ineffective time due to plant
Perfectly
Applied E- T in bad condition
C.8. lmproved Working
tlt-/ m Gonditions enable workers

r T
to work steadily
C.9. Safety measures reduce
ineffective time due to

L -B
accidents
D.l. Sound Personnel Policy
t il and tncentirres reduce
ineffective time due to

U T absence, etc.
f}2. Personnel Policy and
Operator Training reduce
ineffective time due to
n_ _fl carelessness
D.3. Safety Training reduces

L ineffective time due to

accidents

26
 REDUCING WORK CONTENT AND INEFFECTIVE TIME

A motivating climate, a job that allows for variety and a soundly based
wage structure, including, where appropriate, incentive schemes, can motivate the
worker to reduce ineffective time and hence will make for high productivity.
Careless workmanship and the carelessness which leads to accidents are
both the results of bad attitudes of mind on the part of workers. These can be over-
come only by a suitable personnel policy and proper training. It will be seeno therefore,
that management has a very great responsibility for reducing the ineffective time due
to the action or inaction of workers.
This reduction is shown diagrammatically in figure 6.

5. lnter-relationship of the various methods

used to reduce ineffective time

None of the methods discussed can properly be applied in isolation. Each

one has effects on others. It is impossible to plan programmes of work properly
without the standards provided by work measurement. Method study can be used to
simplify the design of the product so that it is both easier to use and easier to produce.
Production planning will be made easier if a sound personnel policy and a well applied
incentive scheme encourage workers to perform reliably. Standardisation will make
the job of material control easier by demanding less variety of materials to be bought
and held in stock. Process research, by eliminating features of the plant that are likely
to break down, should make it easier to apply a proper system of maintenance.
Modern production management aims at increasing the efficiency of
production operation. It does so by looking at several aspects of production, such as
product design and material utilisation, quality control, layout and material handling,
production planning and control, maintenance management and work study. Modern
production management also deals with the systems by which these activities may be
carried out in a rational way, singly or in combination, in the enterprise. Work study
is a powerful tool in this process.

It will be seen that in our discussion in this chapter we have gradually

moved from a study of the question of productivity in the enterprise as a whole to the
productivity of a certain part of it, namely the productivity of the plant and
labour-machines and men. We have looked briefly at some of the methods which
can affect that productivity so as to show the many different ways in which problems
ofproductivity can be attacked. In the rest ofthe book we are going to concentrate on
one of those methods, namely work study.

27
 Chapre4
Workstudy

1. What is work studY?

What is work study, and why should it be selected, from among the many
, techniques discussed in the previous chapter, as the main weapon of attack on the
problem of increasing productivity and as a special subject for this book?

Work study therefore has a direct relationship with productivity. It is most

frequently used to increase the amount produced from a given quantity of resources
with little or no further capital investment.
Work study was widely known for years as "time and motion study", but
with the development of the technique and its application to a very wide range of acti
vities it was felt by many people that the older title was both too narrow and
insuffi ciently descriptive.

2. Work study: a direct means of raising productivity

We have already seen that the factors affecting the productivity of any
enterprise are many, that they vary in importance according to the nature of the ac-
tivities undertaken, and that they are dependent on one another.

t The definition given here is that adopted in the B.S. Glossary, op. cit. 29
 Let us now look at this problem from a different angle. So far, in discussing
the use of various techniques to increase productivity, there has been no mention of
major capital expenditure in plant or equipment. It has been assumed that produc-
tivity would be raised by using existing resources. Productivity can almost always be
greatly increased by heavy investment of money in new and improved plant and
equipment. How much can we expect to gain by using techniques such as work study
to improve the use of existing resources as against investing capital in new plant? Any
comparison made in general terms will only be a rough guide. It is convenient to do
this in the form of a table (taUte t).
It will be seen that one of the effective ways of raising productivity in the
long run is the development of new processes and the installation of more modern
plant and equipment. However, such an approach usually requires heavy capital out-
lay, and can cause a drain on foreign reseryes if the capital equipment cannot be pro-
duced locally. Furthermore, to tackle the problem of improving productivity mainly
through the continuous acquisition of advanced technology may hamper efforts
aimed at expanding employment opportunities. Work study, on the other hand, aims
at approaching the problem of increasing productivity through the systematic analysis
of existing operations, processes and work methods with a view to increasing their ef-
ficiency. Work study therefore usually contributes towards increasing productivity
with little or no extra capital expenditure.

3. Why is work study valuable?

There is nothing new about the investigation and improvement of opera-
tions at the workplace; good managers have been investigating and improving ever
since human effort was first organised on a large scale. Managers of outstanding
ability-geniuses-have always been able to make notable advances. Unfortunately,
no country seems to have an adequate supply of competent managers. The prime
value of work study lies in the fact that, by carrying out its systematic procedures, a
manager can achieve results as good as or better than the less systematic genius was
able to achieve in the past.
Work study succeeds because it is systematic both in the investigation of
the problem being considered and in the development of its solution. Systematic in-
vestigation takes time. It is therefore necessary, in all but the smallest firms, to
separate the job of making work studies from the task of management. The factory
manager or the foreman, in their day-to-day work, with its many human and material
problems, are never free from interruption for long. However capable he may be, a
manager can rarely afford to devote a long time, without interruption, to the study of
a single activity on the factory floor. This means that it is almost always impossible
for him to obtain all the facts about what is happening in the course of that activity.
Unless all the facts are known, it is impossible to be sure that any alterations in
procedure which are made are based on accurate information and will be fully effec-
tive. It is only by continuous observation and study at the workplace or in the area
where the activity is taking place that the facts can be obtained. This means that work
30 study must always be the responsibility of someone who is able to undertake it full
 WORK STUDY

Table l. Direct means of raising productivity

Approach Type of How quickly cm Extent ofimprove- The role ofwork study
improvement rcults be achieved? ment in producdvity

l. Development Basic research High Generally No obvious Method study to

ofnew baslc Applied research years limit improve ease ol
process or Pilot plant operation and
fundamental maintenance at
improvement design stage
of existing
ones
Capital
investment | 2. Ir.tal.o.e Purchase High Immediately No obvious Method study in
I modern or Process research after limit plant layout and to
I higher-capacity installation improve ease of
I plant or of operation when
I equlpment modernising
I or modernise
I existing plant

3. Reduce the Product research Not high Generally Limited-of Method study
work content Product compared months the same (and its extension,
ofthe product development with order as that value analysis) to
Quality I and 2 to be expected improve design for
management from 4 and 5. ease of production
Method study Shorid precede
Value analysis action under
those heads

4. Reduce the Process research Low Immediate Limited, but Method otudy to
work content Pilot plant often ofa reduce wasted
Better ofthe process Process planning high order effort and time in
manage- Method study operating the
merrt Operator training process by
Value analysis eliminating
unnecessary
movement

5. Reduce Work Low May start Limited, but Work measur€-

inefrecdvedme measurcment slowly but often ofa ment to investigate
(whether due Marketing policy e{fect grows high order existing practice,
to management Standardisation quickly locate ineffective
or to workers) Product time and
development set standards
Production ofperformance as
planning a basis for-
and control A, Planning and
Material control control
Planned B. Utilisation of
maintenance plant
Personnel policy C. Labour cost
Improved working control
conditions D. Incentive
Operator training schemes
Incentive schemes
31
 WORK STUDY

time, without direct management duties: someone in a staff and not a line position.l
Work study is a service to management and supervision.
We have now discussed, very briefly, some aspects of the nature of work
study and why it is such a valuable "tool" of management. There are other reasons to
be added to the above. These may be summarised as follows:

(1) It is a means of raising the productive efficiency (productivity) of a factory or

operating unit by the reorganisation of work, a method which normally involves
little or no capital expenditure on plant and equipment.
(2) It is systematic. This ensures that no factor affecting the efficiency of an operation
is overlooked, whether in analysing the original practices or in developing the new,
and that all the facts about that operation are available.
(3) It is the most accurate means yet evolved of setting standards of performance, on
which the effective planning and control of production depends.
(4) The savings resulting from properly applied work study start at once and continue
as long as the operation continues in the improved form.
(5) Itis a "tool" which can be applied everywhere. It can be used with success
wherever manual work is done or plant is operated, not only in manufacturing
shops but also in offrces, stores, laboratories and service industries such as
wholesale and retail distribution and restaurants, and on farms.
(6) It is one of the most penetrating tools of investigation available to the manage-
ment. This makes it an excellent weapon for starting an attack on inefficiency in
any organisation, since, in investigating one set of problems, the weaknesses of all
the other functions affecting them will gradually be laid bare.
This last point is worth further discussion. Because work study is
systematic, and because it involves investigation by direct observation of all the fac-
tors affecting the efficiency of a given operation, it will show up any shortcomings in
all activities affecting that operation. For example, observation may show that the
time of an operative on a production job is being wasted through his having to wait
for supplies of material or to remain idle through the breakdown of his machine. This
points at once to a failure of material control or a failure on the part of the mainten-
ance engineer to carry out proper maintenance procedures. Similarly, time may be
wasted through short batches of work, necessitating the constant resetting of
machines, on a scale which may only become apparent after prolonged study. This
points to poor production planning or a marketing policy which requires looking into.
Work study acts like a surgeon's knife, laying bare the activities of a com-
pany and their functioning, good or bad, for all to see. It can therefore'oshow up"
people. For this reason it must be handled, like the surgeon's knife, with skill and care.
Nobody likes being shown up, and unless the work study specialist displays great tact
in his handling of people he may arouse the animosity of management and workers
alike, which will make it impossible for him to do his job properly.

rA person in a "line" position exercises direct supervisory authority over the ranks below him. A
"staff' appointee, on the other hand, is strictly an adviser with no power or authority to put his recommendations
32 into operation. His function is to provide expert information.
 WOBK STUDY

Managers and foremen have generally failed to achieve the saving and
improvements which can be effected by work study because they have been unable to
apply themselves continuously to such things, even when they have been trained. It is
not enough for work study to be systematic. To achieve really important results it
must be applied continuously, and throughout the organisation. It is no use the work
study man doing a good job and then sitting back and congratulating himself, or being
transferred by the management to something else. The savings achieved on individual
jobs, although sometimes large in themselves, are generally small when compared with
the activity of the company as a whole. The full effect is felt in an organisation only
when work study is applied everywhere, and when everyone becomes imbued with the
attitude of mind which is the basis of successful work study: intolerance of waste in
any form, whether of material, time, effort or human ability; and the refusal to accept
without question that things must be done in a certain way "because that is the way
they have always been done".

4. Techniques of work study and their relationship

Earlier in this chapter it was indicated that the term "work study" embraced
several techniques, but in particular method study and work measurement. What are
these two techniques and what is their relationship to one another?

Method study and work measurement are, therefore, closely linked. Method
study is concerned with the reduction of the work content of a job or operation, while
work measurement is mostly concerned with the investigation and reduction of any in-
effective time associated with it; and with the subsequent establishment of time stan-
dards for the operation when carried out in the improved fashion, as determined by
method study. The relationship of method study to work measurement is shown
simply in figure 7.

' These definitions are those adopted in the B.S. Glossary, op. cit. 33
 WORK STUDY

Figure 7. Work study

METHOD STUDY

To
simplify the job
and
develop more economical
methods of doing it

WORK
MEASUREMENT

To
determine
how long it should
take to
carry out

As will be seen from later chapters of this book, both method study and
work measurement are themselves made up of a number of different techniques.
Although method study should precede the use of work measurement when time stan-
dards for output are being set, it is often necessary to use one of the techniques of
work measurement, such as work sampling (see Chapter 14), in order to determine
34 why ineffective time is occurring and what is its extent, so that the management can
take action to reduce it before method study is begun. Again, time study (Chapter l5
ff.) may be used to compare the effectiveness of alternative methods.
These techniques will be dealt with in detail in the chapters devoted to them.
For the present we must consider the basic procedure of work study which applies to
every study, whatever the operation or process being examined, in whatever industry.
This procedure is fundamental to the whole of work study. There is no short cut.

5. Basic procedure of work study

There are eight steps in performing a complete work study. They are-
l. thejob or process to be studied.
Select
2. Record from direct observation everything that happens, using the most suitable of
the recording techniques (to be explained later), so that the data will be in the most
convenient form to be analysed.
3. Examine the recorded facts critically and challenge everything that is done, con-
sidering in turn: the purpose of the activity; the place where it is performed; the se-
quence in which it is done; the person who is doing it; the means by which it is
done.
4. Develop the most economic method, taking into account all the circumstances.
5. Measure the quantity of work involved in the method selected and calculate a stan-
dard time for doing it.
6. Define the new method and the related time so that it can always be identified.
7. Install the new method as agreed standard practice with the time allowed.
8. Maintain the new standard practice by proper control procedures.
steps l, 2 and 3 occur in every study, whether the technique being used is
method study or work measurement. Step 4 is part of method study practice, while
step 5 calls for the use of work measurement.
These eight steps will all be discussed in detail in the chapters devoted to
method study and work measurement. Before doing so, however, we shall discuss the
background and conditions necessary for work.study to operate effectively.

35
 Chapterj
The human factor
inthe application
of workstudy
1 . Good relations must be established before work study
is applied
Because of their preoccupation with pressing and important problems, some
managers often forget that the people who work with them, particularly those under
them, are as much human beings as they are, subject to all the same feelings, although
they may not be able to display them openly. The man at the bottom of the ladder, the
most humble labourer, resents an injustice, real or imaginary, as much as any other
man. He fears the unknown, and if the unknown appears to him to offer a threat to his
security of employment or to his self-respect he will resist it-if
not openly, then by
concealed non-cooperation or by co-operation that is only half-hearted.
Work study is not a substitute for good management and never can be. It is
one of the o'tools'o in the manager's tool kit. By itself it will not make bad industrial
relations good, although, wisely applied, it may often improve them. This has been the
common experience of ILO management development and consultancy ^^.rssions
everywhere. If work study is to contribute seriously to the improvement of produc-
tivity, relations between the management and the workers must be reasonably good
before any attempt is made to introduce it, and the workers must have confidence in
the sinceriti' of the management towards them; otherwise they will regard it as
another trick to try to get more work out of them without any benefits for themselves.
Of course, in certain conditions, especially where there is widespread unemployment
in a country or an industry, it may be possible to impose work study, but things which
are imposed are accepted reluctantly. If the conditions should change, the application
will probably break down.

2. Work study and the management

It
was said in Chapter 4 that one of the principal reasons for choosing work
study as the subject for this book is that it is a most penetrating tool of investigation.
Because a well conducted work study analysis is ruthlessly systematic, the places
where effort and time are being wasted are laid bare one by one. In order to eliminate
this waste, the causes of it must be looked for. The latter are usually found to be bad
planning, bad organisation, insufficient control, or the lack of proper training. Since
members of the management and supervisory staffs are employed to do these things, it
will look as if they have failed in their duties. Not only this, but the increases in 37
 THE HUMAN FACTOR

productivity which the proper use of work study usually brings about may appear to
emphasise this failure further. Applying work study in one shop can start a chain-
reaction of investigation and improvement which will spread in all directions
throughout the organisation: to the plant engineer's department, the accounts depart-
ment, the design office or the sales force. The skilled worker may be made to feel a
novice when he finds that his methods, long practised, are wasteful of time and effort,
and that new workers trained in the new methods soon surpass him in output and
quality.
Any technique which has such far-reaching effects must obviously be
handled with great care and tact. Nobody likes to be made to feel that he has failed,
especially in the eyes of his superiors. He loses his self-confidence and begins to ask
himself whether he may not be replaced. His feeling of security is threatened.
At first sight, this result of a work study investigation may seem unfair.
Managers, foremen and workers, generally speaking, are honest, hard-working people
who do their jobs as well as they can. They are certainly not less clever than work
study specialists. Often they have years of experience and great practical knowledge.
If they have failed to obtain the most from the resources at their disposal, it is gener-
ally because they have not been trained in, and often do not know the value of, the
systematic approach which work study brings to problems of organisation and perfor-
mance of work.
This must be made clear to everybody from the very beginning. If it is not
made clear, and if the work study man is at all tactless in his handling of people, he
will find that they will combine to obstruct him, possibly to the point where his task is
made impossible.
If the application of work study in an enterprise is to succeed, it must have
the understanding and the backing of the management at all levels, starting at the top.
If the top management, the managing director, the managing agent or the president of
the company does not understand what the work study man is trying to do and is not
giving him his full support, it cannot be expected that managers lower down will ac-
cept and support him. If the work study man then comes into conflict with them, as he
may do in such circumstances, he may well find that he will lose his case, however
good it may be, if an appeal is made to the top. Do not forget that in any organisation
people lower down tend to take their attitudes from the man at the top.
The first group of people to whom the purpose and techniques of work
study must be explained is therefore the management group, the managing director or
managing agent and, in large companies or organisations, the departmental heads and
assistant heads. It is the usual practice in most countries to run short "appreciation"
courses for top management before starting to apply work study. Most work study
schools, management development institutes, technical colleges and work study
organisations run short courses for the managers of companies who are sending staff
to be trained as specialists.
Here it is necessary to give a word of warning. Running even the simplest
and shortest course in work study is not easy, and newly trained work study men are
strongly advised not to try to do so by themselves. They should seek advice and as-
sistance. It is important that an enterprise's work study staff take an active part in the
38 course, but they must know their subject and be able to teach it.
 lf a course for management is to be run, however, the work study man must
try as hard as he can to persuade the man at the top to attend and, if possible, to open
the proceedings. Not only will this show everyone that he has the support of the top
management, but departmental and other managers will make efforts to attend if they
think their "boss" is going to be there.

3. Work studY and the suPervisor

The work study man's most dfficult problem may often be the attitude of
the foremen and supervisors. They must be won over if he is to obtain good results
from his work; indeed, their hostility may prevent him from doing any effective work
at all. The foremen and their assistants represent the management to the worker on
the floor of the shop, and just as departmental managers will take their attitudes from
the top manager, so the workers will take theirs from their supervisors. If it is evident
that the foreman thinks that "this work study stuff is nonsense", the workers will not
respect the specialist and will make no efforts to carry out his suggestions, which, in
any case, have to come to them through their foreman.
Before the work study man starts his work, the whole purpose of work
study and the procedures involved must have been very carefully explained to the
foreman, so that he understands exactly what is being done and why. Unless this is
done, the foreman is likely to be diffrcul! if not actually obstructive, for many reasons.
Among these reasons are the following:

(l) He is the person most deeply affected by work study. The work for which he may
have been responsible for years is being challenged; if, through the application of
work study methods, the effrciency of the operations for which he is responsible is
greatly improved, he may feel that his prestige in the eyes of his superiors and of
the workers will be lessened.
(2) In most firms where specialists have not been used, the whole running of a certain
operation-planning of the programmes of work, development of job methods,
making up of time sheets, setting of piece rates, hiring and firing of labour-may
have been done by the foreman. The mere fact that some of his responsibilities
have been taken away from him is likely to make him feel that his status has been
reduced. No one likes to think he has "lost face".
(3) If disputes arise or the workers are upset, he is the first person who will be called
upon to clear matters up, and it is difficult for him to do so fairly if he does not un-
derstand the problem.
The sources from which foremen and supervisors are recruited differ widely
in different parts of the world. In some countries the foreman is often selected on a
basis of seniority from among the best skilled men in the company. This means that he
is often middle-aged and may be set in his ways. Because most foremen have practised
their occupation or skills for many years, they find it diffrcult to believe that they have
anything to learn from someone who has not spent a very long time in the same oc-
cupation.
The foreman may therefore resent the introduction of a work study man
into his department unless he has had some training to prepare him for it. Since 39
 foremen are nearer to the practical side of the job than the management, and so are
more intimately connected with work study, the work study course that they should
take should be longer and more detailed than that given to the management. Foremen
should know enough to be able to help in the selection ofjobs to be studied and to un-
derstand the factors involved, should disputes arise over methods or time standards.
This means that they should be acquainted with the principal techniques of method
study and work measurement and the particular problems and situations in which
they should be applied. Generally speaking, courses for foremen should be full-time
and of not less than one week's duration. The trainees should be given opportunities of
making one or two simple method studies and of measuring the time of an operation.
The value to the work study man of a foreman who understands and is enthusiastic
a.bout what he is trying to do cannot be overemphasised. He is a powerful ally.

The work study man will only retain the friendship and respect of the
foremdn if he shows from the beginning that he is not trying to usurp his place. The
following rules must be observed:
(1) The work study man must never give a direct order to a worker. All instructions
must be given through the foreman. The only exception to this is in matters con-
nected with methods improvements where the worker has been ordered by the
foreman to carry out the instructions of the work study man.
(2) Workers asking questions calling for decisions outside the technical field of work
study should always be referred to their foreman.
(3) The work study man should never allow himself to express opinions to a worker
which may be interpreted as critical of the foreman (however much he may feel
like it!). If the worker later says to the foreman: " . . . but Mr.- said. . .",
there will be trouble!
ooplay
(4) The work study man must not allow the workers to him off' against the
foreman or to use him to get decisions altered which they consider harsh.
(5) The work study man should seek the foreman's advice in the selection of jobs to
be studied and in all technical matters connected with the process (even if he
knows a great deal about the process). Remember, the foreman has to make it
work from day to day.
(6) At the start of every investigation the work study man should be introduced to the
workers concerned by the foreman. The work study man should never try to start
on his own.

This list of "Do's" and "Don't's" may look frightening but is mainly com-
mon sense and good manners. The workers in any shop can only have one boss
foreman-and everything must be done to uphold his authority. Of course,
-their
once the work study man and the foreman have worked together and understand one
another, there can be some relaxation; but that is a matter ofjudgement, and any sug-
gestion for relaxation should come from the foreman.
A great deal of space has been given to the relationship between the work
study man and the foreman because it is the most difficult of all the relationships, and
it must be good. One of the best methods of ensuring that this is so is to provide both
40 parties with the proper training.
 4. Work study and the worker
When the first conscious attempts at work study were made at the turn of
the century, little was known about the way people behaved at work. As a result,
workers often resisted or were hostile to work study. During the past 40 years,
however, a great deal of research has been carried out to discover more about the way
people behave-the aim being not only to explain that behaviour but, if possible, also
to predict how people will react to a new situation. For a work study specialist this is
an important consideration, since through his interventions he is invariably and con-
tinuously creating new situations.
Behavioural scientists believe that individuals are motivated to act in a cer-
tain way by a desire to satisfy certain needs. One of the widely accepted notions about
needs was developed by Abraham Maslow, who postulated that there are certain
essential needs for every individual and that these needs arrange themselves in a
hierarchical pattern. Maslow argues that it is only when one need becomes largely
satisfied that the next need in the hierarchy will start to exert its motivating influence.
At the bottom of the hierarchy are physiological needs. These are the basic
needs that must be met to sustain life itself. Satisfying his physiological needs will be
the primary concern of any person, and until he has done so he will not be concerned
with any other issues. However, once a worker feels reasonably sure of fulfilling his
physiological needs, he will seek to satisfy the next need in the hierarchy, that of
security. Security is taken to mean a feeling of protection against physical and psy-
chological harm, as well as security of employment. For a worker who has already
satisfied both his physiological and his security needs, the next motivating factor is
that of affiliation, that is wanting to belong to a group or an organisation and to as-
sociate with others. Next on the hierarchical scale is the need to be recognised, and
this is followed by the need for fulfilment (sometimes called "self-actualisation"). This
last need expresses the desire of a person or a worker to be given an opportunity to
show his particular talents.

Maslow's hierarchy of needs

fulfilment

In practice, most people satisfy some of these needs in part and are left with
some that are unsatisfied. In developing countries people are probably preoccupied
more with satisfying needs at the lower end of the hierarchy, and their behaviour
would appear to reflect this fact. In developed countries, on the other hand, where
physiological and security needs are normally largely met people would seem to be
motivated more by needs at the upper end of the hierarchy. 41
 THE HUMAN FACTOR

One of the interesting results of the research carried out in this area, and
which should be of concern to us here, is the discovery that, in order to satisfy affilia-
tion needs, workers associate with each other to form various types of informal
groups. Thus a worker is usually a member of a task group, that is a group composed
of workers performing a common task with him. He may also be a member of various
other groups, such as a friendship group composed of fellow workers with whom he
has something in common or with whom he would like to associate.
This means that in every organisation we have a formal and an informal
structure. The formal structure is defined by the management in terms of authority
relationships. Similarly, there also exists an informal organisation composed of a great
number of informal groups which have their own goals and activities and which bear
the sentiments of their members. Each group, it was found, expects its members to
conform to a certain standard ofbehaviour, since otherwise the group cannot achieve
its goal, whether this be accomplishing a task or providing a means for friendly inter-
action. It was found, for example, that a task group tends to establish among its
members a certain quota for production which may or may not be in line with what a
loreman or a manager wants. In a typical situation, a worker will produce more or
less according to this informally accepted quota. Those who are very high or very low
producers, and who thus deviate substantially from that norm, will be subjected to
pressure from the group to conform to the norm.
Disregarding or ignoring such basic and elementary notions of behaviour
has often created resentment and outright hostility. It is now easy to understand that a
work study man who makes a unilateral decision to eliminate an operation, resulting
in the loss of a job for a worker or a number of workers, is in fact undermining the
basic need for security; a negative reaction can therefore be expected. Similarly, the
imposition of an output quota on a worker or a group of workers without prior con-
sultation or winning their co-operation can yield resentment and breed resistance.
How, then, should a work study man act? The following are some useful
hints:
(l) The problem of raising productivity should be approached in a balanced way,
without too great an emphasis being placed on productivity of labour. In most
enterprises in developing countries, and even in industrialised countries, great in-
creases in productivity can generally be effected through the application of work
study to improve plant utilisation and operation, to make more effective use of
space and to secure greater economy of materials before the question of increas-
ing the productivity of the labour force need be raised. The importance of study-
ing the productivity of all the resources of the enterprise and of not confining the
application of work study to the productivity of labour alone cannot be
overemphasised. It is only natural that workers should resent efforts being made
to improve their efficiency while they can see glaring inefficiency on the part of the
management. What is the use of halving the time a worker takes to do a certain
job or of imposing a production output on him by well applied work study if he is
held back by a lack of materials or by frequent machine breakdowns resulting
from bad planning by his superiors?
(2) It is important that the work study man be open and frank as to the purpose of his
42 study. Nothing breeds suspicion like attempts to hide what is being done; nothing
 THE HUMAN FACTOR

dispels it like frankness, whether in answering questions or in showing information

obtained from studies. work studyo honestly applied, has nothing to hide.
(3) Workers' representatives should be kept fully informed of what is being studied.
and why. They should receive induction training in work study so that they can
understand properly what is being attempted. Similarly, involving the workers in
the development of an improved method of operation can win them over to the
new method and can sometimes produce unexpected results. Thus, by asking
workers the right questions and by inviting them to come forward with explana-
tions or proposals, several work study specialists have been rewarded by clues or
ideas that had never occurred to them. After all, a worker has an intimate know-
ledge of his own job and of details that can escape a work study man. One tried
a^,d tested practice is to invite the workers in a section to be studied to nominate
one of their number to join the work study specialist and, together with the fore-
man, to form a team that can review the work to be done, discuss the results
achieved and agree on steps for implementation.
(4) Although asking for a worker's suggestions and ideas implicitly serves to satisfy
his need for recognition, this can be achieved in a more direct way by giving
proper credit where it is due. In many instances a foreman, a worker or a staff
specialist contributes useful ideas that assist the work study man to develop an
improved method of work. This should be acknowledged readily, and the work
study man should resist the temptation of accumulating all the glory for himself.
(5) It is important that the work study man should remember that his objective is not
merely to increase productivity but also to improve job satisfaction, and that he
should devote enough attention to this latter issue by looking for ways to minimisc
fatigue and to make the job more interesting and more satisfying. In recent years
several enterprises have developed new concepts and ideas to organise work to
this end and to attempt to meet the workers'need lor fulfilment. These are treated
briefly in the last chapter of this book.

5. The work study man

We have talked a great deal in the preceding sections about what is required
from the work study man, suggesting by our requirements a human who is almost too
good to be true. The ideal man for the job is likely to be found very rarely, and if he is
he will quickly leave the ranks of work study men to rise to greater heights.
Nevertheless, there are certain qualifications and qualities which are essential for suc-
cess.

EDUCATION

The very minimum standard of education for anyone who is to take charge
of work study application in an enterprise is a good secondary education with
matriculation or the equivalent school-leaving examination. It is unlikely that anyone
who has not had such an education will be able to benefit fully from a full work study 43
 THE HUMAN FACTOB

training course, although there may be a few exceptions. However, if a work study
man is also to be involved in studying other production management problems, a
university degree in engineering or management or the equivalent becomes an impor-
tant asset.

PRACTICAL EXPER!ENCE
Itis desirable that candidates for posts as work study specialists should
have had practical experience in the industries in which they will be working. This ex-
perience should include a period of actual work at one or more of the processes of the
industry. This will enable ihem to understand what it means to do a day's work under
the conditions in which the ordinary workers with whom they will be dealing have to
work. practical experience will also command respect from foremen and workers, and
an engineering background. enables a man to adapt himself to most other industries.

PERSONAL OUALITIES
Anyone who is going to undertake improvements in methods should have
an inventive turn of mind, be capable of devising simple mechanisms and devices
which can often save a great deal of time and effor! and be able to gain the co-opera-
good
tion of the engineers and technicians in developing them. The type of man who is
at this is not always so good at human relations, and in some large companies the
methods department is separated from the work measurement department, although
both are under the same chief.

The following are essential qualities:

tr Sincerity and honestY

The work study man must be sincere and he must be honest; only if he is
will he gain the confidence and respect of those with whom he has to deal.

tr Enthusiasm
He must be really keen on his job, believe in the importance of what he is
doing and be able to transmit his enthusiasm to the people around him.

tr Interest in and sympathy with people

He must be able to get along with people at all levels. To get along with
people it is necessary to be interested in them, to be able to see their points
of ,i.* and to understand the motives behind their behaviour'

tr Tact
Tact in dealing with people comes from understanding people and not
wishing to hurt their feelings by unkind or thoughtless words, even when
these may be justified. Without tact no work study man is going to get very
far.

tr Good appearance
He must be neat and tidy and look efficient. This will inspire confidence in
44 him among the people with whom he has to work.
 THE HUMAN FACTOR

tl Self-confidence
This can only come with good training and experience of applying work
study successfully. The work study man must be able to stand up to top
management, foremen, trade union officials or workers in defence of his
opinions and findings, and do so in such a way that he will win respect and
not give offence.

The personal qualities, particularly the ability to deal with people, can all be
further developed with the right training. Far too often this aspect of the training of
work study men is neglected, the assumption being that, if the right man is selected in
the first place, that is all that needs to be done. In most work study courses more time
should be given to the human side of applying work study.
It will be seen from these requirements that the results of work study,
however ooscientifically" arrived at, must be applied with "art", just like any other
management technique. In fact, the qualities which go to make a good work study
man are the same qualities as go to make a good manager. Work study is an excellent
training for young men destined for higher management. People with these qualities
are not easy to find, but the careful selection of men for training as work study
specialists will repay itself in the results obtained, in terms both of increased produc-
tivity and of improved human relations in the factory.
Having described the background against which work study is to be ap-
plied, we can now turn to the question of applying it, starting with method study.
Before we do so, however, some attention must be given to some general factors
which have considerable bearing on its effect, namely the conditions under which the
work is done in the area, factory or workshop concerned.

45
 GhapEr6
Working conditions and
the working environment

1. General considerations
It has taken a long time for the full extent of the interdependence between
working conditions and productivity to be properly recognised. The Frst move in this
direction came when people began to realise that occupational accidents had
economic as well as physical consequences, although at first only their direct costs
(medical care, compensation) were perceived. Subsequently, attention was paid to oc-
cupational diseases as well; and as a final step it was realised that the indirect costs of
occupational accidents (working time lost by the injured person, the witnesses and the
accident investigators, production stoppages, material damage, work delays, possible
legal and other costs, reduced output when the injured person is replaced and subse-
quently when he returns to work, and so on) are usually far higher-as much as four
times higher in some cases-than the direct costs.
The reduction in productivity and the increase in production rejects and
manufacturing waste that result from fatigue due to excessively long working hours
and bad working conditions-in particular, lighting and ventilation-have shown that
the human body, in spite of its immense capacity for adaptation, is far more produc-
tive when working under optimal conditions. Indeed, in certain developing countries it
has been found that productivity can be improved merely by improving the conditions
under which people work.
Generally speaking, occupational safety and health and ergonomics have
not been given suflicient consideration in modern management techniques, in spite of
the modern tendency to consider an industrial undertaking as a total system or a com-
bination of subsystems.
These problems have been seen in a different light since public opinion and,
in particular, the trade unions became aware of them. It has been possible to detect in
the stresses imposed by modern industrial technology the source of those forms of dis-
satisfaction which occur, in particular, amongst workers employed on the most
elementary type of repetitive and monotonous jobs which are lacking in any interest
whatsoever.
Thus, not only may a hazardous working environment be a direct cause of
occupational accidents and diseases, but the worker's dissatisfaction with working
conditions which are not in line with his current cultural and social level may also be
at the root of a decline in production quality and quantity, excessive labour turnover 47
 WORKING CONDITIONS AND EI

and increased absenteeism. Obviously, the consequences of such a situation will vary
according to the socio-cultural environment. What, in the industrialised countries, is
o'social cost of labour" has sometimes been aggravated by com-
nowadays called the
bative attitudes (deliberate waste, threats of violence, conflicts) whereas this kind of
reaction has not been encountered elsewhere. Nevertheless, wherever there is a de-
mand for labour, it would be foolish to believe that firms whose working conditions
have not developed in line with technical progress and economic growth can count on
a stable workforce and achieve profitable levels of productivity.
In the developing countries the widespread lack of statistical data on in-
dustrial injuries and on absenteeism makes a detailed study of working conditions im-
possible; moreover, for workers in these countries working conditions may be only a
secondary consideration, to be placed after the employment itself and the wages that
accompany it. However, if one wishes to avoid, in the short term, the wastage of
human and material resources-which is all the more serious in a developing coun-
try-and, in the long term, socio-political tension, great attention must be devoted to
working conditions, and it must be recognised that nowadays the undertaking has an
important social role to play in addition to its technical and economic function.

2. Occupational safety and health organisation

The most effective method of obtaining good results in accident prevention
is to establish good safety organisation within the enterprise. The organisational struc-
ture need not be formalised, nor need it require the employment of specialists; its es-
sential features should be a precise delegation of responsibilities within a structure
which can ensure sustained action and a joint effort by employers and workers to
ooraise
the quality of the working environment, in all its technical, organisational and
psychological aspects, to a satisfactorily high standard".r This implies the introduc-
tion of an effective occupational safety and health education and training programme
and the provision of the necessary first-aid and medical services.

3. Safe{ criteria
Studies of occupational hazards in modern industry have revealed the ex-
tremely complex nature of the possible causes of occupational accidents or diseases.

OCCU PATTONAL ACCI DENTS

The causes of occupational accidents are never simple, even in an appar-

ently commonplace accident; consequently, the number and variety of accident classi-
ficaiions are gieal Statistics show that the most common causes of accidents are not
the most dangerous machines (circular saws, spindle moulding machines, power
presses, for example) nor the most dangerous substances (explosives or volatile flam-
mable iiquids), but rather quite ordinary actions like stumbling, falling, the faulty

rCouncil of Europe, Committee of Ministers: Resolution 76(1) on safety services in Jirms,

48 2O Jan. 1976.
 WORKING CONDITIONS AND ENVIBONMENT

Figure 8. The four basic methods of controlling occupational hazards

classified by decreasing order of effectiveness

o
W-+ tndividual Elimination of hazard

@o
PE2
oc
Hazard -+ Removal of the individual from exposure
-o
qo
602
pts H"*ra -l+
6o
o
" I tndividuat lsolation of the hazard

o
4 Hazard ---+[l,.rdir',duatl Protection of the individual

Source.. Adapted from E. Gniza: 'Zur Theorie der Wsge der Unfallvorh0lwg" , in Arbeitsikonomik und Abeitsschutz lBerlin'|, Vol. 1. 1957
No.1.

handling of goods or use of hand tools, or being struck by a falling object.t Similarly,
those who have accidents most frequenfly are not the disabled but, on the contrary,
those who are the best equipped from the physical and psycho-sensorial point of view,
i.e. young workers.
Technical progress has created new health hazards whilst at the same time
greatly reducing the severity of conventional hazards and significantly improving the
standards of machinery guarding (nevertheless, accidents do still happen even on the
most carefully guarded machines). In addition, since in many countries commuting
accidents have now been brought under the heading of occupational accidents, the
demarcation line between occupational and non-occupational hazards has become
less distinct and the role of the human factor and the importance of the circumstances
attending an accident have become increasingly clear. An accident is often the result
of a combination of technical, physiological and psychological factors: it depends on
both the machine, the environment (lighting, noise, vibration, vaporising substanceso
oxygen deficiency), posture and work-induced fatigue; but it is also conditioned by
commuting circumstances and other activities outside the plant, ill-temper, feelings of
frustration, youthful exuberance and other specific physical or mental states. In the
developing countries there are, in addition, malnutrition, endemic diseases, lack of
adaptation to industrial work and the immense changes that industry has brought to
the worker's individual and family life and customs. It is therefore not surprising that,
nowadays, increasing attention is being paid to the accident hazards inherent in
human behaviour, be it in the factory or elsewhere, and that the problems of
safeguarding the worker's health and welfare are now being examined from a global
viewpoint which admits of no fragmentation for purely administrative reasons.
The first precaution to take in order to avoid accidents is the elimination of
potential causes, both technical and human. The ways of doing this are too numerous
and varied to be listed extensively here. However, to mention but a few, there are the
observance of technical rules and standards, careful supervision and maintenance,
safety training for all workers, and the establishment of good working relationships.
The main technical safety criteria are listed in decreasing order of effec-
tiveness in the diagram developed by Gniza (see figure 8).

I ILO: Accident prevention: A workers' education manual (Geneva, 8th imp., 1976). 49
 WORKING CONOITIONS ANO ENVIRONMENT

Some 30 per cent of all accidents occur in manual handling; work study can
contribute to reducing the incidence of these accidents quite simply by reducing the
number of handling operations and the distance that goods have to be transported. A
sigrrificant percentage of other accidents could be prevented by eliminating dangerous
operations through prior work study, process analysis and flow charts and; in general,
by a critical examination of work organisation with a view to accident prevention.

OCCUPATIONAL DISEASES
The situation relating to the causes of occupational diseases and ways of
preventing them is equally complex. Technical progress has been so rapid that it has
often created new and totally unrecognised hazards which have resulted in occu-
pational diseases even before the disease was recognised as such. Yet this same
technical progress has provided extremely effective tools for the early detection of
signs or symptoms of occupationally induced morbidity, and even exposure tests for
evaluating a hazard before it has any biological effect. The study and monitoring of
the working environment have, in this way, assumed a fundamental importance in the
prevention of occupational diseases.
The traditional approach which made a sharp distinction between oc-
cupational and non-occupational diseases on the basis of insurance criteria has
gradually lost favour in face of a much more realistic understanding of the severity of
the hazards to which the individual is exposed outside the plant-not only home and
traffic accidents (which have a much higher incidence than occupational accidents)
but also noise, air pollution in residential areas, the nervous tension of daily life, and
so on. Moreover, the effects of exposure to occupational hazards are much more
severe in persons who are suffering from pre-existent disease, and who, in the most
developed countries, are increasingly finding their way into the industrial environ-
ment. Thus industrial hygiene has developed at an extraordinary pace and the true
task of the occupational physician has taken on a new significance. Many of the con-
ditions to which workers are subject may be of psycho-neural or psycho-somatic
origin-a field in which any distinction between the occupational and non-occupa-
tional causes of disease is illusory. The task of the plant medical offrcer therefore
extends to protecting the individual from mental and nervous stresses that are often of
unidenffi able primary origin.
Industrial hygiene measures are similar to those that have already been
mentioned for accident prevention. One important point needs to be made, however.
Industrial hygiene has been a subject of study for a much shorter period than oc-
cupational safety. It is a discipline which involves both medical and technical know-
ledge, and this may explain why it is still neglected even today by both occupational
health and occupational safety services. This is the risk run by any interdisciplinary
activity, and ergonomics is no exception to this rule. It is therefore essential that the
management of an enterprise comes to grips with the problem and adopts the most
suitable approaches for its solution; such approaches are not, however, of universal
application since they have to be matched to the individual circumstances of the
enterprise and its workers.
A number of basic general criteria in industrial hygiene can nevertheless be
50 put forward. First of all, as has been found in the field of mechnical safety, in in-
 WORKING CONDITIONS ANO ENVIRONMENT

dustrial hygiene too the most effective means of prevention is that which occurs at the
design stage-be it of a building, plant or work process-since any subsequent
improvement or modification may perhaps be too late to protect the worker's health
and will certainly be more expensive. Dangerous operations (for example, those
resulting in environmental pollution or producing noise or vibration) and harmful sub-
stances which may contaminate the atmosphere at the workplace should be replaced
by harmless or less harmful operations or substances. Where it is impossible to
provide group safety equipmen! use should be made of supplementary work organisa-
tion measures which, in certain cases, may include a reduction of the duration of ex-
posure to risk. Where group technical measures and administrative measures do not
reduce exposure to acceptable levels, workers must be provided with suitable personal
protective equipmenl However, other than in exceptional cases or for special types of
work, reliance should not be placed on personal protective equipment as the basic
means of safety. This is not only for physiological reasons but also a matter of princi-
ple, since the worker may, for a wide range of reasons, fail to make use of this equip-
ment.

4. Fire prevention and protection

The prevention of fire and, in certain cases, explosion and the appropriate
protective measures should receive particular attention, especially in hot and dry
countries and above all in certain industries where a fre may lead to widespread
material damage and, should it occur during working hours, to injury and even death.
The first principle of prevention is to design and construct buildings with
adequate fire resistance in relation to the hazards that are encountered. The second
principle is to give adequate training to the workers and enforce fire prevention regula-
tions such as bans on smoking and the prohibition of the use of sources of ignition in
high-risk areas. It is essential to ensure that, wherever a fire risk may occur, there is an
adequate number of serviceable fire extinguishers which, in themselves, should not
constitute a supplementary hazard (for example, of poisoning or explosion); that
alarm systems function correcfly and that the warning they emit is audible throughout
the enterprise; and firu[y, that emergency exits are kept clear. In particularly
high-risk plants such as are found in the textile industry, sprinklers or similar
automatic fire-fighting apparatus should be installed. It is also important that the
management and foremen should be fully acquainted with their role in the event of a
fire and that the workers themselves should know what they should do; panic at the
outbreak of a fire, especially in a multi-storey buiding, may cause more loss of life
than the fire itself. Where there is a significant ftrehazard, fire protection will entail-

tr a trained fire-fighting team which carries out regular fire-fighting exercises;

tl a system of periodic inspection which rnay include full-time inspectors;
tr suitable liaison with the fire brigade;
tr in large enterprises and with due regard to the costs involved, periodic fire
alarm and evacuation exercises. 51
 WORKING CONDITIONS AND ENVIRONMENT

5. Working premises
It would be inappropriate to deal here with the technical details of plant
location and construction, but certain basic principles need to be appreciated and
applied if the management is subsequently to obtain viable results. This point should
be borne in mind by the work study specialist, especially when plant installation is
being studied.
Neighbourhood and environmental protection are nowadays of such impor-
tance and so closely connected with the prevention of pollution and the suppression of
noise and vibration, even inside the plant, that every enterprise is virtually obliged to
make an over-all study of these problems when considering plant location and installa-
tion. An over-all study is in fact the most economic one in view of the complex re-
quirements that have to be met. Moreover, in many countries it is compulsory to sub-
mit to the competent authority-which may be spread over several ministries-any
plans for a new industrial building in order at least to ensure that all existing standards
are adhered to.
As far as the layout of the workplace is concerned, emphasis should be
placed on the principle of isolating any operation which is hazardous or constitutes a
nuisance. Wherever possible, work premises should be above ground level and equip-
ped with windows having a surface area of not less than 17 per cent of the floor area.
Minimum ceiling height should not be less than 3 metres and each worker should have
at least 10 cubic metres of air (or more where temperatures or the level of atmospheric
pollution are high). For the purposes of accident prevention, it is important to ensure
that each worker has an adequate minimum free-floor area which should not be less
than2 square metres per person.
Walls and ceilings should have a finish which prevents the accumulation of
dirt, avoids moisture absorption and, where necessary, reduces noise transmission;
floor coverings (table 2) should be of the non-slip, non-dust-forming and easy-to-
clean type and should, where necessary, have good electrical and thermal insulation
properties.
if
Traflic aisles should be sufliciently wide to allow, necessary, the
simultaneous movement of vehicles and workers at peak hours (meal times, closing
times) and rapid evacuation in the event of an emergency. When discussing fire
protection, we emphasised that emergency exits should always be kept clear; to this
end, fire exits should not be used for any other purpose. The national regulations of
certain countries specify that no workplace should be more than 35 metres from the
nearest emergency exit or fire escape.

6. Cleanliness and good housekeeping

Building work premises in accordance with safety and hygiene regulations is

not enough, however, if the plant or workshop is not kept clean and tidy. Good
housekeeping, which when used with reference to a factory or workplace is a general
term embracing tidiness and general state of repairo not only contributes to accident
52 prevention but also is a factor in productivity. If aisles and gangways are allowed to
 WORKING CONDITIONS AND ENVIRONMENT

Table 2. Properties of various industrial floor surfacesl

Propertia Type of surface

Conqete Cumic Plastics Plmtics Xytolite Wood Puquet Poured Rolled

tila (2ompo (shet or blaks mphalt bituminous
nmt com- strip) surfacc
pouds)

Abrasion Very Very Very Medium Poor Good Medium Good Good
resistance good good good3 togood togood
Compression Very Very Very Medium Medium Good Medium Medium Good
resistance good god good3 togood
Impact Medium Medium Depen- Good Good Very Good Good Good to
resistance dent good tovery verygood
ontype good
Thermal Bad Bad Badr Bad to Medium Very Very Medium Medium
insulation medium good god
, (contact)
I

Shrinkage, Depen- None Poor Poor Depen- Depen- Depen- None None
stretching dent on denton denton denton
type moisture moisture moisture
content content content
Acid Bad Very Good Usually Bad Good Good Poora Medium
resistance good2 good to bad
Alkali Good Very Poor to Usually Bad Medium Medium Good Good
resistance good very good good to good to good
depending
on type
Water Good Very Good Good Bad Bad Bad Very Good
resistance good good
Oil and fuel Unsuit- Very Good Medium Unsuit- Good Good Unsuit- Good
resistance able un- god2 togood able able
less spe-
cially
treated
Solvent Good Very Certain God Unsuit- Good Good Bad Medium
resistance god types able
resistant
Dust Yes No No No Yes Yes No No
formation
Ease of Satis- Good Very Good Satis- Rela- Satis- Good Medium
cleaning factory good factory tively factory to good
bad to good
Fire Very Very Bad Medium Good Bad Bad Medium Quite
resistance good good good
Dielectric Bad Good Good Good Depends Good Good Good Quite
properties on atme, (if dry) (if dry) good
spheric
humidity
Friction Yes Yes No No No No No No Yes
sparking
I Detemined by the swiss Fedqal
Matdals Tsting Laboratory and RMch Institute (Laboratoire fed&al d'qsai da mat6riaux et lnstilut de
reherche)' Diibendorf, August 1969. 2 Except perhaps thejoints. 3 In these cas in panicular, the charactaistics depend on the filler employed. . The
"acid-rsistmt" type is unaffeted by non-oxidising inorgmic rcids.
Sozrce.' Swiss Federal O(fice ofTrade ud Industry.
53
 WOFKING CONDITIONS AND EI

become cluttered with stacks of materials and other obstructions, time will be lost by
workers having to clear their way for the transport of raw materials or finished
products; it may take hours to find a batch of semi-finished products lost in the
general disorder. Finally, stacks of raw materials or semi-finished products, as well as
tools and equipment that may have been abandoned for some considerable time, tie up
capital and take up space which could be used for productive purposes. Tools, jigs,
fixtures and other equipment should not be left lying around the workshop but should
be returned to store or stowed on shelves or racks or in bins located at suitable points.
Gangways should be marked on the ground with white or yellow lines at least 5 cm
wide and objects should not be allowed to project into them. Depot and storage
areas should be marked in a similar manner and goods should be carefully stacked.
in particular as
Cleanliness is no less important than good housekeeping,
regards the protection of workers against infection, infestation, accidents and
occupational diseases. Where necessary, measures should be taken to exterminate
rodents, insects and other vermin which may be the vectors of epidemic diseases.
Indeed, problems such as this should be prevented by the careful daily cleaning of
workshops, gangways, staircases and any other areas where waste or deposits may at-
tract animals. Waste bins should be leak-free; they should be easy to clean, and they
should be kept clean.
Residues which may be the source of dangerous emissions of vapour, gases
or dust (such as toxic liquids, refractories, asbestos and lead oxide) should be collected
in a suitable way: dust should be removed by vacuum cleaners or wet methods and
chemicals should be neutralised or diluted. Deposits of certain toxic substances can be
more readily identilied if the floor, walls and, where necessary, the work benches are
painted in a colour which contrasts with that of the substance in question.
Working clothes must be kept clean in order to reduce the skin-absorption
hazard of certain toxic substances (analine and its derivatives, benzene, its
homologues and derivatives, organo.phosphorus compounds, tetraethyl lead and
other organic metal compounds, carbon tetrachloride and other solvents, nicotine, and
so on) and the problem of skin sensitisation and chronic or acute irritation. Prolonged
contact of the skin with certain substances (especially mineral oils and aromatic
hydrocarbons) may produce chronic dermatitis, sometimes followed by the develop-
ment of cancer. Workers exposed to toxic substances should have twin-compartment
clothing lockers to keep their working clothes separate from their other clothes, so as
to prevent the danger of their family being exposed to the industrial toxic substance.
Similarly, it is advisable to provide a centralised laundry service for working clothes in
plants using highly toxic substances.
Workers employed on dirty jobs or exposed to dangerous or toxic sub-
stances should have wash-rooms with a tap for every three or four workers and a
shower for every three workers (and never less than one for every eight workers) to
ensure that workers do not give up taking a shower because they have to wait too
long.
An important factor for the worker's health is the provision of suffrcient
and, where posslble, cooled drinking water in the factory. This water should be
approved by the health authority and its punty should be tested periodically. Where
54 possible, the water should be on tap.
 WORKING CONDITIONS AND ENVIRONMENT

7. Lighting
It is estimated that 80 per cent of the information required in doing a job is
perceived visually. Good visibility of the equipment, the product and the data involved
in the work process is an essential factor in accelerating production, reducing the
number of defective products, reducing waste and preventing visual fatigue and
headaches amongst the workers. It may also be added that both inadequate visibility
and glare are frequently a cause of accidents.
Visibility depends on a number of factors: the size of the workpiece, its dis-
tance from the eyes, the persistance of the image, the lighting intensity, the colour of
the workpiece and contrasts of colour and lighting levels with the background. All
these factors should be studied in the case of precision work, work in a dangerous en-
vironment or where there are other reasons for dissatisfaction or complaint. Lighting
is often the most important factor and the one which is most easy to correct.
Above all, the lighting should be adapted to the type of work: however, the
level of illumination should be increased not only in relation to the degree of precision
or miniaturisation of the work (table 3) but also in relation to the worker's age, since
older people require a higher level of illumination than young persons if they are to
recognise detail and maintain a sufftcienfly rapid visual reaction; moreover, older
persons are highly susceptible to glare since their recovery time is longer. It is not suf-
hcient to provide for an optimal lighting level when the workplace layout plans are be-
ing drawn up, since, after installation, lighting intensity rapidly falls by 10 to 25 per
cent and then more slowly until it is only 50 per cent or less of the original level. This
is because of the accumulation of dust and the wear of the lighting elements. Lighting
intensity at the work surface should be checked periodically and all lighting surfaces

Table 3. Recommended minimum values of illumination for various c/asses of visual task

CIN of visual t^k Minimum Typical exmpla

illumination of
tmk (lux)l

Casual seeing 20 To permit safe movement (e.g. in corridors with little trarlic)
100 Boilerhouse (coal and ash handling); dead storage ofrough,
bulky materials; locker rooms
Ordinaryroughtasks 150 Rough, intermittent bench and machine work; rough inspec-
tion and counting of stock parts; assembly of heavy
machinery
Moderately critical tasks 300 Medium bench and machine work, assembly and inspec-
tions. Ordinary olfice work such as reading, writing, filing
Critical tasks 7m Fine bench and machine work, assembly and inspection;
extra-fine painting, spraying; sewing dark-coloured goods
Very critical tasks l5@ Assembly and inspection of delicate mechanisms; tool- and
die-making; gauge inspection; fine grinding work
Exceptionally dilfi cult 3@ or more Fine watchmaking and repairing
or important tasks
I
Th* figures refer to the mm value of illumination obtained during the tife of the installation md avaaged over the work plue or specific tck
tea (i.e. the secalled "wice value of illumination').

Soarce.' ILO, Intemadoml Occupational Safety and Health Infomation Cmre (CIS): Artlficial lighting in factory and oiice, CIS Informa-
tion shet no. I I (GeneYa" 1965).

55
 WORKING CONDITIONS AND ENVIRONMENT

Table 4. Recommended maximum lighting intensity ratios

Points involved

Between tie work and the immediate environment 5tol

Between the work and distant surfaces 20to I
Between the light source or the sky and adjacent surfaces 40to I
All points in the worker's immediate vicinity 80to I

should be kept clean. In general, the light should be uniformly diffused (figures 9, 10
and 11); slight shadows help to distinguish objects, but shadows that are too
pronounced should be avoided. Excessive contrasts in lighting levels between the
worker's task and the general surroundings should also be avoided. Table 4 shows the
maximum intensity ratios that should be observed in order to prevent the development
ofvisual fatigue and health disorders such as conjunctivitis and headaches.
Natural lighting should be used wherever possible, through windows which
should have an area equal to at least one-sixth of the floor area. However, since the in-
tensity of natural lighting is extremely variable (even where the inflow can be modified
by the use of shutters, blinds or sbades), since its level falls rapidly as the distance
from the windows increases, and since it is likely that reflected sunlight will cause
glare, artificial lighting must be provided to ensure suitable conditions of visibility in
all seasons, at all times and in all weather conditions. Fluorescent lighting offers con-
siderable potential for rational use, provided that glare is avoided (figure l2), since it
has particularly good colour-rendering properties and its annual cost (including
depreciation and installation costs) falls, in relation to incandescent lighting, as the
number of hours of use increases (figure 13). Thus the member of hours an installation
is likely to be used per year should influence the type of lighting chosen.

USE OF COLOURS
Experience shows that the careful choice of interior colour schemes makes a
valuable contribution to good lighting (figure 14). The colours used at the workplace
have psychological effects which should not be overlooked, and when the time comes
to repaint workshops and offrces it costs very little, if anything, more to select pleasing
rather than drab colours; the workers will see in this a clear sign that the management
is making an effort to make working conditions more pleasant.
The colours of machinery and equipment are supplementary safety factors
and their importance has been recognised by the manufacturers of machine tools and
electrical equipment, as a result of the work of the International Organization for
Standardization.

8. Noise and vibrationl

NOISE
High levels of mechanisation, increased machine speeds, the density of
machinery at the workplace and the lack, until recenfly, of detailed knowledge of the
t For further information on this subjec! see ILO: Protection ofworkers againsl noise andvibration
56 in the working environment (Geneva,1977).
 WORKING CONDITIONS AND ENVIRONMENT

Figure 9. Mounting of general lighting units

4-
This

is better than

----+
this

Goneral lighting units should proferably be mounted as high as possible

Source.'lLO, CfS:,4ttificial lighting.. ., op. cit.

Figure lO. Need for general lighting

t.,'/ t.,'- ta.," tt'

2 2

Some general lighting is always noeded even when tasks are locally lit. (l) Uniform general lighting (21 Local supplemen-
tary lighting.
Sourcei lLO. CIS: /4 ttificial lighting . . ., op. cit.

Figure ll. Maximum recommended spacing for industrial type units

/';f ,'-"T.1

; u -l - I riu -----J-i n

Measurements are to the centro point of the unit in all cases, and aro expressed as a multiple of tho mounting height h
above the work plane (l), The % f figure applies when there is a gangway next to the wall, whilst the 1A D figure is used
when people work close to the wall. For louvred units, maximum spacing between fittings should be reduced lo 1y4 h.
Sourcej lLO, CIS:l rtificial lighting . . .. op, cit. 57
 WORKING CONDITIONS AND ENVIRONMENT

Figure 12. Factors influencing the degree of glare produced by a given diffusing fitting
(or a bare fluorescent lamp unit)

Glare is worse when the mounting height of the in-

stallation is lowered, since the lighting units then ,
approach closer to the horizontal line of sight.

This is more glaring than this

(21 Size of room

Glare is worse in large rooms than in small ones,

because of the additional glare produced by the
many distant units which are seen close to tho
horizontal line of sight.

This is more glaring than this

l3l Orientation of lighting unit

When a substantial amount of light is emittod from

the sides of a fluorescent fitting, the unit will be
much more glaring when viowed broadside-on than
when viewed end-on, since in the latter case th€
L apparent area of the bright side panels (1) will be
I greatly diminished. This does not apply to the
I horizontal base panel (2), for though this panel looks
This is more
a different shape. its apparent area remains the
same; hence the glare produced by recessed units
glaring than this (and units with unlit sides) is much the same
regardless of whether they are viewed endwise or
-> crosswise.

Sourcer lLO. CIS:/ rtiticial lighting . . -. op. cit.

Figure 13. Relative cost of incandescent and fluorescent lighting

G
q
o

t
o
.E
C (1 ) Fixed capital charges
OJ (21 Point of equal cost
aq
o= r Fluorescent lighting
fo rr lncandescent lighting
la
Fs
oo
#o
E
=o
@
t2t

=
d
:--1t,t
___: {>
Annual hours of use

58 Source: lLO. CIS:Anificial lighting. . ., op. cit.

 WOBKING CONDITIONS AND ENVIRONMENT

Figure 14. Recommended ranges of reflection factor for main interior surtaces

REFLECTION
FACTOR
(PER CENTI

-too_
-95 WHITE
CEILINGS _ 85
-90- &
7solo MtN. I -ao- ) NEAR.WHITE
-75
-70-
_ 65 I LIGHT

-60- 55
-
r COLOURS

-50-
-45
FURNITURE, -40-
EOUIPMENT, -15 MEDIUM
DADOS -30-
COLOURS
(IF REOUIRED)
-et

-20-
FLOORS -t5

to_
-7
l-

-3
2-

-,
o-

Source.'f LO, CIS:,4 rtificidl lighting . . ., op. cit.

hazards and nuisance factor of noise have resulted, in many plants, in workers being
exposed to noise levels which are nowadays considered excessive. Noise is the cause
It
of various problems. impedes sound communication (flrgure l5), first, by the
acoustical masking effect which every sound has on other sounds of the same fre-
quency or immediately higher frequencies and which reduces the intelligibility of
speech that is not more than 10 dB louder than the background noise; and second, by
temporarily raising the acoustic threshold in the event of exposure to a noise ex-
ceeding 78-80 dB (figure 10. It may cause sensori-motor, neuro-vegetative and
metabolic disorders; it has been named as a cause of industrial fatigue, irritation,
reduced productivity and occupational accidents. Prolonged exposure to noise above
certain levels causes permanent damage to hearing and results in occupational
deafness.
It is considered that exposure to continuous noise levels of 90 dB(A) or
above is dangerous to hearing; but the figure of 85 dB(A) is already a warning level
which should not be exceeded. Special care should be taken in the case of impulse
noises, i.e. noises of very short duration at a level of at least 3 dB above the
background noise and separated by intervals of at least one second, which the more
rudimentary type of measuring instrument may not be able to detect. However, not all
acoustic frequencies have the same effects on hearing: the most dangerous frequencies
are those around 4,000 Hz (and higher in the case of impulse noise). Each time the
sound level increases by 6 dB, the sound pressure doubles and the acoustic energy is 59
 WORKING CONDITIONS AND ENVIRONMENT

Q)
.3 :
@
or
\ z
NO
si
o
o o
L
5)
r<
o
uk
O= L
@

G
a o'a
ta
o<
z= o9
.\ ul 'E
G o Gtr
L
U)
(! o ur<
! >-.
o
B za @

E
s
q)
E,=
U!
a az--
Pi
o (/)t
Q)
(J =E
os
o Fi
cca
N trl
a .!

o
Y:
<+
L E
Q)
e >r
q n8
-LBul:
\ oci
Zc
$ F'o
QJ o .t2
o OP
a
.3
d3
a @

o
Lcj 'a
A) 6'E
NO
o.E
Bl
TL o
t
@

?
@

!
g
E t-l
.i
E
o
I
'd
o\
o:
o6
oooo
F@6q

{v)sp Nl uv3 s.u3NrJ-slr l.v l3n3l lsloN

60
 WORKING CONDITIONS AND ENVIRONMENT

Figure 16. Temporary hearing threshold shift in dB as a function of duration of exposure

to wide-band noise

trt
c

,20
-c
.;i

q
o
F

exposure in minutes
Source: A. Glorig, W. D, Ward and J. Nixon: "Damage risk crit€ria and noise-included hearing loss", in Archives of Otolaryngology lchi-
cago lll.), Vol. 74,1961,p.413. Copyright'1961. American MedicalAssociation.

quadrupled; thus it is considered that, for an increase of 3 to 5 dB in the sound level,

the duration of exposure must be halved if the biological effect is to remain un-
changed. Nobody should be exposed to levels of over 115 dB without hearing protec-
tion.
Anyone who has done intellectual work, or work requiring intense con-
centration, in a noisy environment such as a weaving mi[ or a workshop full of
automatic machines-even where the noise level does not reach levels which may
cause occupational deafness-will know just how fatiguing noise can be. Intermittent
noise from rams used for digging the foundations for heavy machines, riveting ham-
mers, pile-drivers or large mechanical presses is particularly disturbing. Numerous in-
vestigations have shown that a reduction in the background noise is accompanied by a
marked decrease in the number of errors and a significant improvement in production.
The most effective method of noise control is to reduce the noise at source
by, for example, replacing noisy machines or equipment by less noisy ones; this means
(as is always the case with preventive action) that these measures must be borne in 6i
 mind at the design stage of a production process, the construction of a building or the
purchase of equipment (tables 5 and 6). Particular attention should be given to ventila-
tion equipment since, in many workshops, recent concern about the prevention of at-
mospheric pollution at the workplace has led to the installation of ventilation equip-
ment which, when in operation, has raised the background noise to 85 to 90 dB and
above, even before the production machines are started up. The second method is to
prevent or reduce noise transmission by the installation of noise-absorbant barriers
between the noise source and the worker and by the damping of structures which may
be the source of secondary reverberation, or by isolating the noise source in separate
premises or a sound-proofed enclosure (this may also require modification of the foun-
dations to prevent the transmission of vibration through the floor). Where such
measures are not applicable or are not sufficiently effeotive, it may be necessary to
provide workers with sound-proofed cabins (ventilated or, where necessary, air-con-
ditioned) from which they can operate the machines and do their work without having
to enter the noisy environment except for short periods. Where workers are
systematically exposed to a noise level of 90 dB(A) for eight working hours, the dura-
tion of noise exposure should be reduced to bring the situation back within acceptable
limits (table 7).
Personal noise protection, which in its simplest form consists of ear-plugs
made from glass fibre or foam plastic, can reduce exposure to hazardous frequen-
cies by at least 15 to 20 dB; however, workers sometimes object to this type of protec-
tion. In fact, personal noise protection should be considered as no more than a
provisional remedy until the workplace is permanently modified or whenever special
conditions make its use necessary. Workers should be informed of the nature of the
noise exposure hazard and the requisite protective measures, including work methods
which reduce noise and noisy work to specific hours. In view of the particularly in-
sidious nature of occupational deafness (which may go unnoticed for a considerable
time since it does not affect the human-voice frequencies until it has reached an ad-
vanced stage), these warnings should be repeated periodically. Workers who are
systematically exposed to noise levels above the danger level should receive a periodic
audiometric examination.

VIBRATION
Although only a limited number of workers are exposed to vibrations which
constitute a health hazard, the necessary protective measures should not be neglected.
The most effective protection is afforded by technical and organisational methods
which, if applied to the extent required, can prevent health impairment.

9. Climatic conditions
If
productivity is to be maintained, climatic conditions at the workplace
must not place an extra burden on the worker; this is also a factor in safeguarding the
worker's health and comfort. Members of the first ILO productivity mission to India
reported that in some of the factories and mills they visited nothing or virtually
nothing had been done to mitigate the effects of heat, so that the workers had to go
into the open air to recover from the o'unbearable working conditions". As a result a
62 great deal of time was lost.
 WORKING CONDITIONS ANO ENVIFONMENT

Table 5. Calcutation of noise level obtained by adding a new background noise source
to a pre-existing noise

Diference in dB betwen Increm in dB ofthe

the two noise levels higher noise level

0 3

I 2.8
2 2.1
3 1.8
4 1.5
5 1.2
6 1.0
7 0.8
8 0.6
9 0.5
10 0.4

Table 6. Calculation of noise level obtained by removing a source of noise

from the background noise

Di{Ierene in dB betwen Reduction in dB ofthe

the two noisc levels higher nois level

I 7.0
2 4.4
J 3.0
.} .,
4
5 1.8
6 1.3
7 1.0
8 0.8
9 0.6
10 0.5

Table 7, Duration of continuous noise exposure which should not be exceeded to ensure
the prevention of occupational deafness amongst the maiority of workers

Daily duration of Nois level in dB(A)

noirc in hours (memured "slow')

l6 80
8 85
4 90
2 95
I 100
v, r05
Yt ll0
,/* ll5
,Sozrce.. Americm Conference ofGovmmental Industrial Hygienists (ACGIH): Threshold llmit valtesfor chemical substances and phlsical ogents
in rhe workroom environment adopted by ,he ACGIH tot I 977 (Cincimaq Ohio).

63
 WORKING CONDITIONS AND ENVIFONMENT

Figure 17. Limits of heat exposure

(J
li
o
EO

Continuous
75 per cent work - 25 per cent rsst each hou.
- 50 per cent work - 50 per cent rest each hour
25 pe. cent work - 75 per cent rost each hour

100 200 300 400 500

Kcal/hr.
400 800 1200 1600 2000
BTU/hr.
Rate of Work

Source: ACGIH, op. cit.

The human body's job here is to keep the central nervous system and the in-
ternal organs at a constant temperature. It maintains the necessary thermal balance
by continuous heat exchange with the environment. The extent of this exchange de-
pends, on the one hand, on air temperature, ventilation, humidity and radiant heat
and, on the other, on body metabolism. During physical activity, metabolic values
may be up to ten times as much as those encountered at rest. Under normal climatic
conditions, in order to avoid over-heating (which sooner or later proves fatal) the heat
that the body is continually producing must be dissipated in larger quantities when
work is being done and in still larger quantities again if it is absorbing heat from a
high-temperature environment.
In all cases it is essential to consider thermal burden in relation to the
energy expenditure required by the work, since the body has to deal with a combina-
tion of these stress factors. The more burdensome the climatic conditions, the longer
the work breaks should be (figure l7).

HOT WORK
In a hot working environment the only way, or almost the only way, in
which the body can dissipate heat is by sweat vaporisation. This vaporisation is more
intenseo and consequently more effective and refreshing, where it is made easier by
adequate ventilation; it is less effective when the relative humidity of the air is high.
Thus the working conditions that are most difficult to bear are those encountered in
64 deep mines, in spinning and weaving mills in hot countries, in sugar refineries and, in
 WORKING CONDITIONS AND ENVIRONMENT

general, in all work entailing exposure to hot, humid conditions, especially in tropical
countries. However, highty unfavourable working conditions may also be found in a
desert-type, dry climate when radiant heat and a high air temperature are combined,
in iron and steel works, in foundries, around surface treatment furnaces and in glass
works, hot rolling mills and forges.
In view of the diffrculty of evaluating conditions-which are determined by
four parameters (air temperature, ventilation, humidity, radiant heat) which are all in-
dependently variable-several indices of thermal stress have been adopted, the most
common being the wet bulb globe temperature (WBGT) index. Prevention may take
various forms, for example, technical and work organisation measures which, if they
are applied at the right level, can prevent any deleterious health effects.

COLD WORK
Work in low temperatures is more common now than it was, but prac-
titioners in occupational medicine are still less familiar with it than with work in high
temperatures. Workers in refrigerated premises should be well protected from the cold
by suitable clothing and footwear, and exposure to low temperatures should alternate
with periods at normal temperatures; moreover, workers should be protected from
dehydration by frequently taking hot drinks. In the case of workers in non-heated
premises, modern technology may provide means of localised heat, such as infra-red
heaters directed at the workers, which can prolong the exposure time without affecting
the worker's health or producing too marked a fall in output. For work in the open,
national regulations usually require the installation of sheds or other means of protec-
tion against the weather.

WET WORK
As has already been mentioned, high levels of humidity are poorly tolerated
at high temperatures, in particular when there is a significant workload. It is con-
sidered that the temperature as indicated by the wet-bulb thermometer at the
workplace should not exceed 70oF (21"C). It is extremely difficult to keep within this
limit in hot countries, in circumstances where (as in the textile industry) the process re-
quires a high level of atmospheric humidity or (as in laundries, canning plants and
various chemical plants) produces large quantities of steam. In the first case it is
necessary to reduce the temperature by ventilation; in the second, to remove the steam
by exhaust ventilation.
Excessive humidity is also poorly tolerated in combination with low
temperatures; the relative humidity should be kept within a range of 40 to 70 per cent.
Excessively dry air can be a cause of respiratory tract diseases; consequently, this
should be avoided in winter in over-heated premises.

TEMPERATURE AT THE WORKPLACE

In view of the complexity of the physical factors affecting a worker's ap-
preciation of the climatic enyironment, and the role of energy expenditure and per-
sonal factors such as nutrition, personal habits, age, sex and clothing, it would be a
hopeless task to attempt to ensure the thermal comfort of all workers (i.e. a situation
in which they require neither cooler nor warmer air). Experience shows that, among 65
 WORKING CONDITIONS AND ENVIRONMENT

the workers in a given shop, some would prefer more ventilation and some less, some
tend to feel cold whilst others feel at ease. It may often be found that the main objec-
tive reason for these differences in a single shop is that the jobs being done by certain
workers demand greater physical effort than those being done by others. The follow-
ing air temperatures have been recommended for various types of work:
OF oc
Sedentary work 68-72 20-22
Light physical work in a seated position 66-68 L9-20
Light work in a standing position (e.g. on machine-tools) 63-65 l7-18
Moderate work in a standing position (e.9. assembly) 6l-63 1,6-17
Heavy work in a standing position (e.g. drilling) 57-61 14-16

Working premises should be laid out and the work stations arranged in such
a way as to ensure the greatest uniformity of energy expenditure amongst the persons
working in a given area, in order to provide optimum climatic conditions for the ma-
jority of workers, with allowance being made for the effect of thermal comfort on out-
put especially in the case of intellectual work.

VENT!LATION
The cubic volume of working premises can never be large enough to make
ventilation unnecessary, since ventilation is the dynamic parameter that complements
the conaept of air space: for a given number of workers, the smaller the work premises
the more intense should be the ventilation.
Ventilation must not be confused with air circulation: the first replaces con-
taminated air by fresh air, whereas the second merely moves the air without renewing
it. Wh'ere the air temperature and humidity are high, merely to circulate the air is not
only ineffective but, beyond certain limits, increases heat absorption by convection;
nevertheless, there still exist hot workplaces fitted with fans which simply stir the air
without renewing it.
Workplace ventilation-
tr disperses the heat generated by machines and men at work (the mechanical
efficiency is such that usually only 20 per cent of the energy employed is
converted into work whereas 80 per cent is released as heat); consequently,
where machines or workers are grouped together, ventilation should be in-
tensified;
tr dilutes atmospheric contamination; it is easy to calculate the ventilation in-
tensity required, on the basis of the quantity of substances being released
into the air and the maximum concentration that should be observed;
tr maintains the feeling of air freshness.
In all, adequate ventilation should be looked upon as an important factor in maintain-
ing the workeros health and productivity.
Except for confined spaces, all working premises have some minimum ven-
66 tilation; however, to ensure the necessary air flow (which should not be lower than 50
 WORKING CONDITIONS AND ENVIRONMENT

cubic metres of air per hour per worker), air usually needs to be changed between four
and eight times per hour in oflices or for sedentary workers and between eight and
12 times per hour in workshops; the air flow may be as high as 15 to 30 air changes
or more for public premises and where there are high levels of atmospheric pollution
or humidity.
The air speed used for workplace ventilation should be adapted to the air
temperature and the energy expenditure: for sedentary work, it should not exceed 0.2
metre per second but for a hot environment the optimum speed is between 0.5 and 1
metre per second. For arduous work it may be even higher. Certain types of hot work
can be made tolerable by directing a stream of cold air at the workers. Ventilation,
correctly used, is one of the most important technical means of making tolerable cer-
tain types of extremely arduous working conditions such as are encountered in
deep mines and tropical countries, i.e. anywhere where there is a combination of high
atmospheric temperature and relative humidity.

Natural ventilation, obtained by opening windows or wall or roof air-vents,

can produce significant air flows but can usually be used only in relatively mild
climates. The effectiveness of this type of ventilation depends largely on external con-
ditions that usually vary considerably. When ventilation is most needed, natural ven-
tilation is often at its least effective; moreover, it is relatively difficult to regulate. In
addition, for natural ventilation to be effective, the outlet vents must be correctly
located and of sufficient size, especially in hot countries where ventilation apertures
are, only too often, too small.

Where natural ventilation is inadequate, artificial ventilation has to be used.

A choice may be made between a blown-air system or an exhaust-air system, or a
combination of both systems. Blown-air ventilation or blown-and-exhaust-air com-
binations allow better regulation of air movement. The majority of blown-air ventila-
tion systems are used both to heat and to ventilate premises; when the temperature is
high, they can also be used for cooling. However, in the long term, the air inflow
deposits dust at the workplace and a layer of dirt on free surfaces and electric light
bulbs; in the presence of flammable or explosive vapours, it is a source of danger.
Wherever there are large emissions of gas, vapours, mists, fumes or dust, it is
preferable to instal exhaust ventilation, which promotes the convection of heated air
and avoids the dispersion of polluants into neighbouring premises.

Where general ventilation is inadequate, local exhaust ventilation is re-

quired, by means of exhaust hoods or other devices which can be designed to meet the
requirements of each case. The specific gravity of the polluant in relation to that of air
should be ascertained, in order io decide whether the exhaust ventilation should be
downwards or upwards. The substance exhausted is never pure but is mixed with air
in varying ratios, and it is the specific gravity of this mixture that should be con-
sidered; what is essential is to ensure that the exhausted air does not pass through the
worker's breathing zone. Exhaust ventilation installations should be made from cor-
rosion-resistant and non-combustible materials in view of the corrosive action of cer-
tain polluants and the fire or explosion hazard of various organic or metallic dusts,
solvent vapours and other volatile substances; the additional cost of the installation
will always be lower than that of any possible accidents and the repeated replacement
of ducting. 67
 WORKING CONDITIONS AND ENVIRONMENT

10. Exposure tests

The protection of the worker's health against toxic substances should com-
bine control of the working environment by the exposure limit method and medical
supervision, including exposure tests. Such tests exist for a number of occupational
hazards (lead, benzene, toluene, mercury, carbon disulphide, carbon monoxide,
various organo-phosphorus insecticides, cadmium, etc.) and make it possible to
monitor the degree of exposure of a worker even where no clinical signs or symptoms
are detectable by conventional medical examinations, specialised though these may
be. They are of great preventive value; unfortunately, however, in the majority of
cases they require relatively complex equipment and trained and experienced person-
nel, neither of which are easily found in a developing country. In these countries and
in small enterprises in general, the most effective and least expensive means of protec-
tion should be selected. Monitoring the environment makes it possible to protect the
majority of workers without, however, guaranteeing 100 per cent protection of every
exposed person; in addition, monitoring is relatively inexpensive. Medical supervision
is more effective for a population which is exposed not only to occupational hazards
but also to endemic, infectious and parasitic diseases and to malnutrition, as is often
the case in developing countries. However, in conditions such as these, the specific
control of occupational hazards is neglected, first because it is terribly time-consum-
ing for the physician, and second, because oflack ofresources and knowledge.
In more developed countries medical check-ups and exposure tests may be
resisted if they are not imposed by law or incorporated in collective bargaining agree-
ments. These tests are still relatively expensive at present and involve a certain loss of
working time and careful organisation. Where the competent authority is prepared to
make exceptions to the rule regarding very frequent compulsory periodical medical
examinations on condition that exposure tests give satisfactory results, these tests may
be very economical since they are always less expensive than a medical examination
and are of much greater specific effectiveness. Although medical examinations will
still continue, they will be carried out less frequently.
Finally, no matter what method or combination of methods is finally
selected, it is unthinkable to protect the worker's health against occupational hazards
without the worker's own comments being taken into account. These are of specific
value in cases of exposure to irritant or sensitising substances.

11. Personal protective equipment

For certain severe occupational hazards, neither technical prevention nor
administrative arrangements can ensure an adequate degree of protection. It is
therefore necessary to institute a third level of defence, i.e. personal protective equip-
ment. This type of equipment is justified in emergency situations such as a severe acci-
dent, a leak or a fire, or under exceptional circumstances such as those attending work
in confined spaces. In other cases the provision and maintenance of this equipment
may be expensive and some workers may resist its use. It is therefore advisable for
representatives of the management and the workers to examine the matter jointly
beforehand and to seek the opinion of the safety and health committee, where one
68 exists.
 Where there is no other effective means of protection, the enterprise must
provide a suffrcient quantity of suitable personal protective equipment, instruct the
workers in its correct use and ensure that it is worn. The choice of equipment should
be made with the assistance of specialists, since advice is required both on the equip-
ment's effectiveness and on its ergonomic characteristics, i.e. its adaptation to the
worker's physical and functional characteristics.

12. Ergonomics
The effects of health and safety on productivity cannot be properly dis-
cussed without touching on the concept of ergonomics. This term covers a field which
in recent years has expanded to an extraordinary degree and whose boundaries are far
from clear. Ergonomic measures may, however, be defined as those that go beyond
the mere protection of the worker's physical integrity and aim at ensuring his well-
being through the attainment of optimal working conditions and by the most suitable
use of his physical characteristics and physiological and psychological capabilities.
Productivity is therefore not the primary objective of ergonomics but is usually one of
the end products. The task is to develop the most comfortable conditions for the
worker as regards lighting, climate and noise level, to reduce the physical workload (in
particular in hot environments), to improve working postures and reduce the effort of
certain movements, to facilitate psycho-sensorial functions in reading instrument dis-
plays, to make the handling of machine levers and controls easier, to make better use
of spontaneous and stereotyped reflexes, to avoid unnecessary information recall
efforts, and so on.
Many ergonomic measures are of a kind that should be introduced at the
design stage of a building, appliance or machine, or when equipment is being installed,
since subsequent modifications are generally less effective and much more expensive.
A machine user should incorporate the application of specific ergonomic standards in
the clauses of his contract with the machine manufacturer. The contract should cover
safety colou-s, warning lights and controls that have already been standardised by the
International Organization for Standardization and the International Electrotechnical
Commission, in particular display panels and dials (figures l8 and 19). In addition, at-
tention should be given not only to items affecting production but also to critical
maintenance features.
It would be wrong to consider ergonomics as merely a collection of
sophisticated actions reserved for the latest technology; improvements are often poss-
ible in manual handling also. In general, for work requiring frequent lifting, it is ad-
visable to use a well trained worker. The correct technique is to bend the knees,
holding the back straight so that the lifting is done by the powerful thigh muscles
rather than by the weaker back muscles (figure 20). The instruction of manual-
handling workers in kinetic techniques and systematic training is essential for the
prevention of low-back pain and ir{uries to the lumbar spine which are among the
most frequent causes of absenteeism, especially amongst older workers.
In medium-sized and large enterprises a well tried technique for introducing
an ergonomic programme is to set up one or more interdisciplinary teams comprising 69
 WORKING CONDITIONS AND ENVIRONMEN't

Figure 18. Ergonomic display design

A, TYPES OF OISPLAY

l-\
EBBiI o (\*-'r/
(l
ryt
r Attificial Statrc Dynamic

m
td
t:l
m @ fltrl m
Analo8ue 0rgital Pictoilal Qualitative Quantitative

B. SCALE PATTERNS

Good designs r----r----r-T rffi-rrT-r.-'l rffirr-l lffi-rffi-rl

78
tltt
Poor designs I--T--T-T r.r-._T-1 .T-r--a--r rrffiIffil
78

Good designs
@ [rTrr-rl

Poor rlesiSns Ht=

u9.J

Suporior design C. OIAL PATTERNS Reasof,ablo alternatives

D. DISPLAY STEREOTYPES

'O: I-ffir ***o*'t'|'

H
70 Source.'W. T. Singleloil lntroduction to ergonomics lGeoeva, World Health Organization, 1972), pp. 79-8O.
 WORKING CONDITIONS AND ENVIRONMENT

Figure 19. Ergonomic design of controls

A. TYPES OF CONTBOL use Stscrel delr8n,eNtre@nls

Eulld ffi harsnto,aodsrect,@ f0 &rd sliDint inrer af,d accrdenlel aclivsto

Elftoiart6,uur6s
V)

6 F0 &finrle.,relv u$d acrd To ssrd ercessrw inler lr6sut or @rl 6@&

Tmle lryiln8@lrchd(dho
o
U

Fq@rha&oedk$ To avord erceslrw rrsl ac!@ @b Idrl @@nl lesg

&ledd rtun t800.

fr Do rcl @ sr@le crrclllr sMF

Knob F0c@ln@vana'res
sta€ &Bds @rnly @ ra3rslsna6 to dr6
Us ardla. $@ rlh $mlod dl!
C

Craot
meo olahd lh,qh @E thao Cnp hadle sield lu,n fidlt @ Sfl
3m rs ndd

Fe hr8E, lda6s or wry lden!ftca!@ ol @u!rl d rero

l@ddicatd pirculil FsrX63

@
c,
Sel [fiv#;e?';i.*,'#""* ABrd slrmrnS

B. CRITERIA FOR CONTROL POSITIONS AmToucAr BYCHOLMICAL

fhen Gd
mrh ld lirah lo,d?

Srar
$dl&r Hrgi

sbP
Had 0h Colu

Iasl'ln8s Hrgh
Lryd

ffBi

nrgh'k

C. IDENTIFICATION OF CONTROLS D. CONTROLSTEREOTYPES

ETHOD IHEX

il tf
USED

EXAIPLE
861gl&d m& to cddtrd hGt@
P6inoil O O O (Mr6ldss@ @d8llMfu&cs!
B Ml3 d nrgh s8od is d
660
lryhd ir tslali@ lo hrSh iimEy
s,z€ / d @ (6.t.p*ek @ tyFfrite)d
in €tato lo ryrqh8 16@. S'rs
$eld b G@sd iS r@,d 16c6.
@
SIAPT Urtul fr@ rd@l! N bo @rt€d
nhd vi@l eltdi@.
Ofl,*l
lJsfulslya!@drry@@6
\J {1,/l
c0LouR tminS @la tido a6 W cdol!
toSdhor. E6&(@!6rdcdm
uaed 3n@ld d ba @ tne fi@. el
L/1 o, l

I m-l F@nl Arrows indicat€ dirsction of movemsnt expected to ,rrr"*'":

LECETO

eo tisful sordary @, Seld

dcd rlE cdol is oryated.
db
incrsase.
Standard position of switch indicating "on" or
ons country to anoth€r.
"off' diffeB from

Source.'W. T. Singloton, op. clt.. pp. 69-70. 71

 WORKING CONDITIONS AND ENVIRONMENT

Figure 2O. Optimal use of physical.effort

A. ASPECTS OF WEIGHT DTSTRIBUTION

To a9Dly a domward lorce

trong Right Wrong Right

hAfuM
R
lYIonB Right wrons Risht

ftqqq F
B. LIFTING AND CARRYING

Rishr ;' .d'-'

A [S- I\s-
Ilrofl8

MF Y{r) \[- Right llrong

)ld-
I
Right
Srong

7 2
$ {il in
source.'w. T. Singleton. op. cit., p.25.
 WORKING CONDITIONS AND ENVIFONMENT

work study specialists, a safety specialist, the works medical officer, a representative
of the personnel department and representatives of the workers in the shops in ques-
tion.

13. Arrangement of working timel

HOURS OF WORK
In most countries working hours are nowadays regulated by law and are
negotiated through collective bargaining procedures. In some countries about 40
hours per week are worked, although elsewhere (for example, in certain enterprises in
Sweden and the United States) the figure has been reduced to 36 hours and further
reductions are under consideration. In other countries, such as Switzerland, the figure
still exceeds 40 hourso reaching 48 hours in many of the smaller enterprises. Overtime
poses a problem in that some workers, with an eye to economic gain, tend to accept
this kind of work readily. In the long run this can adversely affect both the quality and
the quantity of the work produced. Limits should be set and applied regarding the
amount of overtime that may be worked during a given period. Similarly, workers
below 18 years of age and expectant mothers should not be allowed to work overtime.

BREAKS
Only some 30 years ago, the need for rest breaks during the working day
was recognised by few industries. Although recent technological progress has,
generally speaking, reduced the arduousness ofvarious types ofphysical work, it has
often increased the psycho-physical workload by accelerating the work tempo and
eliminating work preparation time. These changes have made it necessary to introduce
breaks during the working day in order to dissipate fatigue and restore the worker's
physical and nervous energy. During these breaks a person doing hard physical work
should be able to stop work, sit down and if possible lie down; a person doing intellec-
tual work should be able to move around and even do some light gymnastics. Inter-
ruptions for meals or resulting from accidents should not be counted as breaks.

THE CONTINUOUS WORKING DAY

The continuous working day, in which there is only a short break for a light
meal at midday, represents a compromise between established eating and social habits
and the new requirements created by industrialisation. Where the continuous working
day is introduced, the workers' leisure time is increased and the number of commuting
journeys is reduced. Consequently, fatigue is reduced too and there are fewer acci-
dents; from the employers'point of view, productivity is increased as a result of the in-
troduction of a continuous working schedule and the satisfaction of a union demand.
Even where the continuous working day has met with resistance (this is particularly

t This subject is dealt with in greater detail in the following ILO publications: Hours of work in
industrialised countries, by A. A. Evans (Genevq 1975); Flextble working hours, by H. Allenspach (Geneva,
1975); Shift work: Economic advantages and soclal cosrs, by M. Maurice (Genevq 1975); Adapting working
hours to modern needs, by D, Mari6 (Geneva, 1977); Management of working time in industrialised countries
(Geneva, 1978). 73
 WORKING CONDITIONS AND ENVIRONMENT

likely from older workers), the system has been encouraged because it is in the in-
terests both of the enterprise itself and of the majority of the workers.

STAGGERING OF WORK SCHEDULES

Systems of staggered hours of work are now being adopted in the most in-
dustrialised countries. Workers are usually content with systems of this kind since
they tend to reduce the amount of peak-hour road and rail traffic and allow workers
to shop and to make use of public services during the week, without requesting special
permission from their employer. Moreover, the system has the advantage that it in-
creases social intercourse and contacts. It is dfficult to introduce and organise stag-
gered hourso however, for workers engaged on continuous or line production. Before
such a system is adopted, all interested parties, in particular the representatives ofthe
workers, should meet together and carefully study all its implications.

FLEXIBLE WORKING HOURS

A major innovation in the arrangement of working time was carried
through when variable or flexible patterns of work were successfully adopted in cer-
tain European countries. This system, of which there are several forms with varying
degrees of flexibility, allows the worker to choose the times at which he wishes to start
and finish his working day, provided that he observes a oocore" period of compulsory
attendance and puts in a certain number of working hours each day, month, or even
longer working period. It is difficult to apply a system of flexible working hours for
shift work or semi-shift work or where production is organised in a number of very
fragmented operations. However, it lends itself particularly well to jobs in the tertiary
sector, where workers have been highly satisfied with the system because it allows
them to choose their hours of work to fit in with their life style or individual or group
work tempo. Where such a system can be introduced without provoking too much
friction between the various categories of worker or too much resistance from certain
people in the industrial hierarchy who are often hostile to any innovation, the
enterprise can put the flexible working hours system to good use in solving certain
problems of manpower and management and also in facilitating the employment of
married women.

SHIFT WORK
Shift work is common in several industries, particularly for certain opera-
tions such as oil refining, continuous steel production, and so on. Shift work may take
one of three forms:

(a) two shifts of eight hours each (indicated as 2 x 8) with an interruption of work at
the end of the day and of the week;
(b) three shifts of eight hours each (or 3 x 8) with an interruption for the week-end; or
(c) fully continuous operations with no stoppages and including work on Sundays
74 and public holidays. Such a system needs more than three shifts (4 x 8 or 5 x 8).
 WORKING CONDITIONS AND ENVIBONMENT

Shift workers may either work the same shift or alternating shifts. Shift
work can have an effect on the health of workers, particularly in the case of fully con-
tinuous operations where alternating shift work may cause some workers to develop
nervous, digestive or circulatory problems. Permanent and occasional night-shift
workers should therefore be given periodic medical examinations. In order to alleviate
other drawbacks of shift work, for instance those concerning the family and social life
of the workers concerned, compensatory measures should be applied to the greatest
extent possible. These include better distribution of work among the various shifts,
reduction of working time, additional rest periods, limitation of the time spent on shift
work and better canteen, transport and housing facilities.

75
 Parttwo
Methodstudy
 GhaptetZ
Introduction
to method study and
the selection of iobs
1. Definition and objects of method study
Method study has already been delined in Chapter 4, but the definition is
worth repeating at this point.

The term "method study" is being increasingly used in place of "motion

study", although the latter was intended by its inventor, Frank B. Gilbreth, to cover
almost exactly the same field. Industrial engineering terminology, published by the
American Society of Mechanical Engineers, gives separate definitions for "method
study" and "motion study", the latter being confined to hand and eye movements at
the workplace. However, "motion study" is sometimes used in textbooks with the
same meaning as "method study".
The objects of method study are-
tr The improvement of processes and procedures.
tr The improvement of factory, shop and workplace layout and of the design
of plant and equipment.
tr Economy in human effort and the reduction of unnecessary fatigue.
tl Improvement in the use of materials, machines and manpower.
tl The development of a better physical working environment.

There are a number of method study techniques suitable for tackling

problems on all scales from the layout of complete factories to the smallest move-
ments of workers on repetitive work. In every case, however, the method of procedure
is basically the same and must be carefully followed. 79
 METHOD STUDY AND THE SELE

2. Basic procedure

When any problem is examined there should be a definite and ordered

sequence of analysis. Such a sequence may be summarised as follows:

l. DEFINE the problem.

2. OBTAIN all the facts relevant to the problem.
3. EXAMINE the facts critically but impartially.
4. CONSIDER the courses open and decide which to follow.
5. ACT on the decision.
6. FOLLOW UP the development.
We have already discussed the basic procedure for the whole of work study,
which embraces the procedures of both method study and work measurement. Let us
now examine the basic procedure for method study, selecting the pfoper steps. They
are as follows:

D SELECT the work to be studied.

D RECORD all the relevant facts about the present method by direct
observation.

D EXAMINE those facts critically and in ordered sequence, using the

techniques best suited to the purpose.

D DEVELOP the most practical, economic and effective method, having

due regard to all contingent circumstances.

E DEFINE the new method so that it can always be identified.

D INSTALL that method as standard practice.

D MAINTAIN that standard practice by regular routine checks.

These are the seven essential stages in the application of method study:
none can be excluded. Strict adherence to their sequence, as well as to their content, is
essential for the success of an investigation. They are shown diagrammatically on the
chart in figure 21.
Do not be deceived by the simplicity of the basic procedure into thinking
that method study is easy and therefore unimportant. On the contrary, method study
may on occasion be very complexo but for purposes of description it has been reduced
80 to these few simple steps.
 METHOD STUOY AND THE SELECTION OF JOBS

Figure 21. Method study

(Reproduction and adapted by permission of lmperial Chemical lndustries Ltd, London)

METHOD
STUDY
lo loprcva mdtod!
of

Dlrin. rcopr of ttud,

Oulline proce$
Flow process
- man type
- malerial typ€
Multiple activity
Travel

Flow diagram
Slriog diagram
Models

Ellmlnela

a ra(ord o, an lmprovad method

I
ne{r.minG
lhll re.ord to ert.blith
Plt.nrng and (ontrol
Mrl.rr.lr handling Manual conlaob
Gcncral envt.onncnt and and vitual
,orling Condltlon! Equrpm!nl dGtign
Pl.nl larout Jig! .nd nxturc.
L@l cotrdlllont
Dellnc
Drq6t o. prccdura - l.tout -.quipmlnt materialt gurliry inllrucfion
- - - -,orktog condilio[
I
I lnrlall
I
lh! improved method
I
plan arrange implamcnl
- -

Vcrllr al regular inte.vrlt ihal

lhc improvcd method it defined i. tn facl in ute

lhprovcd f!<tory lnd

wo.kplaao hrou,

Betier wgrklng .ondition! HIGHER

R€duction of ratiguG
PRODUCTIVTTY
ln improvcd uta
Mat.ri.l
Pl.nl.nd equipment
Manpowcr

81
 METHOD STUDY AND THE SELECTION OF JOBS

3. Selecting the work to be studied

SOME FACTORS INVOLVED
When a studyman is considering whether a method study investigation of a
particular job should be carried out, certain factors should be kept in mind. These
afe-
l. Economic considerations.
2. Technical considerations.
3. Human reactions.

l. Economic considerations will be important at all stages. It is obviously a

waste of time to start or to continue a long investigation if the economic importance of
the job is small, or if it is one which is not expected to run for long. The first questions
must always be: "Will it pay to begin a method study of this job?", and: "Will it pay
to continue this study?"
Obvious early choices are-
..bottlenecks" which are holding up other production operations;
movements of material over long distances between shops, or operations in-
volving a great deal of manpower or where there is repeated handling of
material;
operations involving repetitive work using a great deal of labour and liable
to run for a long time.

2. Technical considerations will normally be obvious. The most important

point is to make sure that adequate technical knowledge is available with which to
carry out the study. ExamPles are-
(a) The loading of unfired ware into kilns in a pottery. A change in method might
bring increased productivity of plant and labour, but there may be technical reas-
ons why a change should not be made. This calls for the advice of a specialist
in ceramics.
(b) A machine tool constituting a bottleneck in production is known to be running at
a speed below that at which the high-speed cutting tools will operate effectively.
Can it be speeded up, or is the machine itself not robust enough to take the faster
cut? This is a problem for the machine-tool expert.

3. Human reactions are among the most important factors to be taken into
consideration, since mental and emotional reactions to investigation and changes of
method have to be anticipated. Experience of local personnel and local conditions, and
awareness of what has been mentioned in Chapter 6 in this respect, should reduce the
difficulties. Trade union officials, workers' representatives and the operatives
themselves should be instructed in the general principles and objectives of method
study. If, however, the study of a particular job appears to be leading to unrest or ill-
feeling, leave it alone, however promising it may be from the economic point of view.
If other jobs are tackled successfully and can be seen by all to benefit the people work-
ing on them, opinions will change and it will be possible, in time, to go back to the
82 original choice.
 METHOD STUDY AND THE SELECTION OF JOBS

THE FIELD OF CHOICE

The range ofjobs which may be tackled by method study in any factory or
other place where materials are moved or manual work is carried on (including
routine office work) is usually very wide. Table 8 gives the general field of choice,
starting from the most comprehensive investigation covering, possibly, the whole
operation of the plant and working down to the study of the movements of the in-
dividual worker. Beside each type ofjob are listed the recording techniques with which
it may be tackled. It should be pointed out that, in the course of a single investigation,
two or more of these techniques may be used. These techniques will be described in
subsequent chapters.
When selecting a job for method study it will be found helpful to have a
standardised list of points to be covered. This prevents factors from being overlooked
and enables the suitability of different jobs to be easily compared. A sample listt is
given below which is fairly full, but lists should be adapted to individual needs.

l. Product and operation.

2. Person who proposes investigation.
3. Reasonfor proposal.
4. Suggested limits of investigation.
5. Particulars of the job.
(a) How much is2 (many are) produced or handled per week?
(b) What percentage (roughly) is this of the total produced or handled in the shop
or plant?
(c) How long will the job continue?
(d) Will more or less be required in future?
(e) How many operatives are employed on the job-
(i) directly?
(ii) indirectly?
(/) How many operatives are there in each grade and on each rate of pay?
(g) Whatis the average output per operative (per team) per day?
(h) What is the daily output compared with the output over a shorter period? (e.g.
an hour)
(i) How is payment made? (team work, piecework, premium bonus, time rate,
etc.)
Q Whatis the daily output-
(i) of the best operative?
(ii) of the worst operative?
(k) When were production standards set?
0 Has the job any especially unpleasant or injurious features? Is it unpopular (a)
with workers? @) with supervisors?

tThis list has been adapted from one given in Anne G. Shaw: The purpose and practice of motion
s/ady (Buxton (United Kingdom), Columbine Press,2nd ed., 1960).
2
For bulk materials measured in tons, pounds, feet, kilograms, metres, etc. 83
 METHOD STUDY AND THE SELECTION OF JOBS

Table 8. Typical industrial problems and appropriate method study techniques

Type ofjob Recording technique

sequence
Complete Manufacture of an electric motor from Outline process chart
ofmanufacture raw material to dispatch. Flow process chart
Transformation of thread into cloth from Flow diagram
preparation to inspection.
Receipt, packing and dispatch offruit.
Factory layout: Movements of a diesel engine cylinder Outline process chart
movement of materials head through all machining operations. Flow process chart-material type
Movements of grain between milling Flow diagram
operations. Travel chart
Models
Factory layout: Labourers servicing spinning machinery Flow process chart-man type
moviment of workers with bobbins. String diagram
Cooks preparing meals in a restaurant Travel chart
kitchen.
Handling of materials Putting materials into and taking them Flow process chart-material type
outofstores. Flow diagram
products.
Loading lorries with finished String diagram
Workplace layout Light assembly work on a bench. Flow process chart-man type
Typesetting by hand. Two-handed process chart
Multiple activity chart
Simo chart
Cyclegraph
Chronocyclegraph
Gang work or automatic Assembly line. Multiple activity chart
machine operation Operator looking after semi-automatic Flow process chart-equipment
lathe. type
Movements oloperatives Females operatives on short-cycle Films
at work repetition work. Film analysis
Operations demanding great manual Simo chart
dexterity. Memotion photography
Micromotion analysis

6. Equipment.
(a) What is the approximate cost of plant and equipment?
(b) Whatis the present machine utilisation index?
1

7. Layout.
(a) ls the existing space allowed for the job enough?
(b) ls extra space available?
(c) Does the space already occupied need reducing?
8. Product.
(a) Arethe frequent design changes causing modifications?
(b) Canthe product be altered for easier manufacture?
(c) Whatqualrty is demanded?
(d) When and how is the product inspected?

84 I Machine utilisation index : the ratio of Machine Running Time to Machine Available Time.
9. What savings or increase in productivity may be expectedfrom a method improve-
ment?
(a) Through reduction in the work content of the product or process.
(b) Through better machine utilisation.
(c) Through better use of labour.
(Figures may be given in money, man-hours or machine-hours or as a percentage).
Item 4 deserves some comment. It is important to set clearly defined limits
to the scope of the investigation. Method study investigations so often reveal scope for
even greater savings that there is a strong temptation to go beyond the immediate ob-
jective. This should be resisted, and any jobs shown up as offering scope for big
improvements through method study should be noted and tackled separately.
Such a list will prevent the work study man from going first for a small
bench job which will entail a detailed study of the worker's movements and yield a
saving of a few seconds per operation, unless the job is one that is being done by a
large number of operatives, so that the total saving will significantly affect the
operating costs of the factory. It is no use playing around with split seconds and
inches of movement when a great waste of time and effort is taking place as a result
of bad shop layout and the handling of heavy materials.
Finally, remember the adage: "Do not use a spoon when a steam shovel is
needed."
Subject to the considerations listed above, tackle first the job most likely to
have the greatest over-all effect on the productivity of the enterprise as a whole.

85
 Cha@!
Record, examine, develop

1. Recording the facts

The next step in the basic procedure, after selecting the work to be studied,
is to record all the facts relating to the existing method. The success of the whole
procedure depends on the accuracy with which the facts are recorded, because they
will provide the basis of both the critical examination and the development of the
improved method. It is therefore essential that the record be clear and concise.
The usual way of recording facts is to write them down. Unfortunately, this
method is not suited to the recording of the complicated processes which are so com-
mon in modern industry. This is particularly so when an exact record is required of
every minute detail of a process or operation. To describe exactly everything that is
done in even a very simple job which takes perhaps only a few minutes to perform
would probably result in several pages of closely written script, which would require
careful study before anyone reading it could be quite sure that he had grasped all the
detail.
To overcome this difficulty other techniques or "tools" of recording have
been developed, so that detailed information may be recorded precisely and at the
same time in standard form, in order that it may be readily understood by all method
study men, in whatever factory or country they may be working.
The most commonly used of these recording techniques are charts and
diagrams. There are several different types of standard chart available, each with its
own special purposes. They will be described in turn later in this chapter and in subse-
quent chapters. For the present it will be suffrcient to note that the charts available fall
into two groups-

(a) those which are used to record a process sequence, i.e. a series ofevents or hap-
penings in the order in which they occur, but which do not depict the events to
scale; and
(b) those which record events, also in sequence, but on a time scalq so that the
interaction of related events may be more easily studied.

The names of the various charts were listed in table 8 in the last chapter
against the types of job for which they are most suitable. They are shown again in
table 9, which lists them in the two groups given abow, and also {ists the types of
diagram commoily used. 87
 RECORO, EXAMINE, OEVELOP

Table 9. The most commonly used method study charts and diagrams

A. CHARTS indicating process SEQUENCE

Outline Process Chart
Flow Process Chart-Man Type
Flow Process Chart-Material Type
Flow Process Chart-Equipment Type
Two-Handed Process Chart

B. CHARTS usingaTIMESCALE
Multiple Activity Chart
Simo Chart

C. DIAGRAMS indicating movement

Flow Diagram
String Diagram
Cyclegraph
Chronocyclegraph
Travel Chart

Diagrams are used to indicate movement more clearly than charts can do.
They usually do not show all the information recorded on charts, which they supple-
ment rather than replace. Among the diagrams is one which has come to be known as
the Travel Chart, but despite its name it is classed as a diagram.

PROCESS CHART SYMBOLS

The recording of the facts about a job or operation on a process chart is
made much easier by the use of a set of five standardr symbols, which together serve
to represent all the different types of activity or event likely to be encountered in any
factory or office. They thus serve as a very convenient, widely understood type of
shorthand, saving a lot of writing and helping to show clearly just what is happening
in the sequence being recorded.
The two principal activities in a process are operation and inspection. These
are represented by the following symbols:

IPERATIIN
O

lndicates the main staps in a process, method or pro-

cedurg. ttsually,the perl, matedal or- produ#t sonccrnod
is modified or changed during tho operation

tThe symbols used throughout this book are those recommended by the American Society of
Mechanical Engineeis and adopted in the B.S. Glossary, op. cit. There is another set of symbols stilt in fairly
common use, an abbreviated foim of the set originated by F. B. and L. M. Gilbreth. It is recommended that the
88 ASME symbols should be adopted in preference to those of Gilbreth.
 RECORD, EXAMINE, DEVELOP

It will be seen that the symbol for an operation is also used when charting a
procedure, as for instance a clerical routine. An operation is said to take
place when information is given or received, or when planning or calculating
takes place.

INSPECTION

clear-
The distinction between these two activities is quite
An operation always takes the material, component or service a stage
further towards completion, whether by changing its shape (as in the case of a
machined part) or its chemical composition (during a chemical process) or by adding
or subtracting material (as in the case of an assembly). An operation may equally well
be a preparation for any activity which brings the completion of the product nearer.
An inspection does not take the material any nearer to becoming a com-
pleted product. It merely verifies that an operation has been carried out correctly as to
quality and/or quantity. Were it not for human shortcomings, most inspections could
be done away with.
Often a more detailed picture will be required than can be obtained by the
use of these two symbols alone. In order to achieve this, three more symbols are
used-

D TRANSPORT

A transport thus occurs when an object is moved from one place to another,
except when such movements are part of an operation or are caused by the
operative at the work station during an operation or an inspection. This
symbol is used throughout this book whenever material is handled on or
offtrucks, benches, storage bins, etc.
TEMPORARY STORAGE OR DELAY

89
 RECORD, EXAMINE, DEVELOP

Examples are work stacked on the floor of a shop between operations, cases
awaiting unpacking, parts waiting to be put into storage bins or a letter
waiting to be signed.

PERMANENT STORAGE

A permanent storage thus occurs when an object is kept and protected

against unauthorised removal.
The difference between a "permanent storage" and a'otemporary storage or
delay" is that a requisition, chit or other form of formal authorisation is
generally required to get an article out of permanent storage but not out of
temporary storage.
In this book, for the sake of simplicity, temporary storage or delay will be
referred to in brief as o'delay", and permanent storage as just oostorage".

Combined Activities. When it is desired to show activities performed at the

same time or by the same operative at the same work station, the symbols
for those activities are combined, e.g. the circle within the square represents a com-
bined operation and inspection.

THE OUTLINE PROCESS CHART

It is often valuable to obtain a "bird's-eye" view of a whole process or ac-
tivity before embarking on a detailed study. This can be obtained by using an oufline
process charl

In an outline process chart, only the principal operations carried out and the
inspections made to ensure their effectiveness are recorded, irrespective of who does
them and where they are performed. In preparing such a chart, only the symbols for
"operation" and "inspection" are necessary.
In addition to the information given by the symbols and their sequence, a
brief note of the nature of each operation or inspection is made beside the symbol, and
90 the time allowed for it (where known) is also added.
 RECORD, EXAMINE, DEVELOP
,

An example of an outline process chart is given in figure 23.\n order that

the reader may obtain a firm grasp of the principles involved, the assembly
represented on this chart is shown in a sketch (figure 22) and the operations charted
are given in some detail below.

EXAMPLE OF AN OUTLINE PROCESS CHART:

ASSEMBLING A SWITCH ROTORl
The assembly drawing (figure 22) shows the rotor for a slow make-and-
break switch.

Figure 22. Switch rotor assembly

It consists of a spindle (l); a plastic moulding (2); a stop pin (3).

In making an outline process chart it is usually convenient to start with a

vertical line down the right-hand side of the page to show the operations and inspec-
tions undergone by the principal unit or component of the assembly (or compound in
chemical processes)-in this case the spindle. The time allowed per piece in hours is
shown to the left of each operation. No specific time is allowed for inspections as the
inspectors are on time work.
The brief descriptions of the operations and inspections which would nor-
mally be shown alongside the symbols have been omitted so as not to clutter the
figure.
The operations and inspections carried out on the spindle which is made
from follows:
10 mm diameter steel rod are as

Operation I Face, turn, undercut and part offon a capstan lathe (0.025 hours).
Operation 2 Face opposite end on the same machine (0.010 hours).
After this operation the work is sent to the inspection department for-

'This example is adapted from W. Rodgers: Methods engineering chart and glossarl (Nottingham
(United Kingdom), School of Management Studies Ltd.). 91
 RECORD, EXAMINE DEVELOP

Inspection 1 Inspect for dimensions and finish (no time fixed). From the inspection
department the work is sent to the milling section.
Operation 3 Straddle-mill four flats on end on a horizontal miller (0.070 hours).
The work is now sent to the burring bench.
Operation 4 Remove burrs at the burring bench (0.020 hours).
The work is returned to the inspection department for-
Inspection 2 Final inspection of machining (no time).
From the inspection department the work goes to the plating shop for-
Operation 5 Degreasing (0.0015 hours).
Operation 6 Cadmium plating (0.008 hours).
From the plating shop the work goes again to the inspection defiartment
for-
Inspection -3 Final check (no time).
The plastic moulding is supplied with a hole bored concentric with the
longitudinal axis.
Operation 7 Face on both sides, bore the cored hole and ream to size on a capstan
lathe (0.080 hours).
Operation 8 Drill cross-hole (for the stop pin) and burr on two-spindle drill press
(O.O22 hours).

From the drilling operation the work goes to the inspection department
for-
Inspection 4 Finil check dimensions and finish (no time).
It is then passed to the finished-part stores to await withdrawal for as-
sembly.

It will be seen from the chart that the operations and inspections on the
moulding are on a vertical line next to that of the spindle. This is because the moulding
is the first component to be assembled to the spindle. The stop-pin line is set further to
the left, and if there were other components they would be set out from right to left in
the order in which they were to be assembled to the main item.

Note especialty the method of numbering the operations and inspections.

It will be seen that both operations and inspections
start from 1. The
numbering is continuous from one component to another, starting from the right, to
the point where the second component joins the first. The sequence of numbers is then
transferred to the next component on the left and continues through its assembly to
the first component until the next assembly point, when it is transferred to the compo-
nent about to be assembled. Figure 23 makes this clear. The assembly of any compo-
nent to the main component or assembly is shown by a horizontal line from the ver-
tical operation line of the minor component to the proper place in the sequence of
operations on the main line. (Sub-assemblies can, of course, be made up of any
92 number of components before being assembled to the principal one; in that case the
 RECORD, EXAMINE, DEVELOP

Figure 23. Outline process chart: switch rotor assembly

STOP PIN PLASTIC MOULDING SPINDLE

5 mm diam. P. F. Resin
BSS 3214 Steel Moulding 7 0 mm diam. S. 69 Sree/

(0.025) (0.080) (0.025)

(o.oo5) (o.o22l (0.010)

No time No time No time

(o.oo15) (o.070)

(o.oo6) (o.020)

No time No time

(o.oo15)

(o.oo8)

No time

(o.020)

(o.045)

No time

horizontal joins the appropriate vertical line which appears to the right of it.) The as-
sembly of the moulding to the spindle, followed by the operation symbol and number,
is clearly shown in the figure.

Operation 9 Assemble the moulding to the small end of the spindle and drill the
stop-pin hole right through (0.020 hours).
Once this has been done the assembly is ready for the insertion of the stop
pin (made from 5 mm diameter steel rod), which has been made as follows:

Operation 10 Turn 2 mm diameter shank, chamfer end and part off, on a capstan
lathe (0.025 hours).
Operation 11 Remove the "pip" on a linisher (0.005 hours).
The work is then taken to the inspection department. 93
 RECORD, EXAMINE, DEVELOP

Figure 24. Some charting conventions

Subsidiary Main
component component

Change in size Now

or condition assembly
shown thus

Repeats
shown thus
(note Repeat 3 more times
subsequent
numbdring)

Inspection 5 Inspect for dimensions and finish (no time).

After inspection the work goes to the plating shop for-
Operation 12 Degreasing (0.00 15 hours).
Operation 13 Cadmium plating (0.006 hours).
The work now goes back to the inspection department for-
Inspection 6 Final check (no time).
94 It then passes to the finished-part stores and is withdrawn for-
 RECOBD, EXAMINE, DEVELOP

Operation /4 Stop pin is fitted to assembly and lightly riveted to retain it in position
(0.045 hours).
Inspection 7 The completed assembly is finally inspected (no time).
It is then returned to the finished-parts store.
Inpractice, the oufline process chart would bear against each symbol,
beside and to the right of it, an abbreviated description of what is done during the
operation or inspection. These entries have been left out of figure 23 so that the main
sequence of charting may be seen more clearly.
Figure 24 shows some of the conventions used when drawing outline
process charts. In this instance the subsidiary component joins the main part after in-
spection 3, and is assembled to it during operation 7. The assembly undergoes two
more operations, numbers 8 and 9, each of which is performed four times in all, as is
shown by the "repeat" entry. Note that the next operation after these repeats bears the
number 16, not 10.
As was explained earlier in this chapter, the oufline process chart is intended
to provide a first "bird's-eye" view of the activities involved, for the purpose of
eliminating unnecessary ones or combining those that could be done together. It is
usually necessary to go into detail greater than the outline process chart provides. In
the following pages the flow process chart will be described and its use as a tool of
methods improvement illustrated.

FLOW PROCESS CHARTS

Once the general picture of a process has been established, it is possible to
go into greater detail. The first stage is to construct a flow process sharL

95
 RECORO. EXAMINE, DEVELOP

A flow process chart is prepared in a manner similar to that in which the

outline process chart is made, but using, in addition to the symbols for "operation"
and "inspection", those for "transport" r'odelay" and "storage".
Whichever type of flow process chart is being constructed, the same sym-
bols are always used and the charting procedure is very similar. (It is customary to
use the active voice of verbs for entries on man type charts, and the passive voice on
material type and equipment type charts. This convention is more fully explained in
Chapter 10, section 3). In fact, it is usual to have only one printed form of chart for all
three types, the heading bearing the words "Man/Materia/Equipment Type", the two
words not required being deleted.
Because of its greater detail, the flow process chart does not usually cover
as many operations per sheet as may appear on a single outline process chart. It is
usual to make a separate chart for each major component of an assembly, so that the
amount of handling, delays and storages of each may be independently studied. This
means that the flow process chart is usually a single line.
An example of a material type flow process chart constructed to study what
happened when a bus engine was stripped, degreased and cleaned for inspection is
given in irgure 25. This is an actual case recorded at the workshop of a transport
authority in a developing country. After discussing the principles of flow process
charting and the means of using them in the next few pages, we shall go on to consider
this example in detail. Man type charts are discussed in Chapter 10.
When flow process charts are being made regularly, it is convenient to use
printed or stencilled sheets similar to that shown in figure 26. (In charts of this kind
the five symbols are usually repeated down the whole length of the appropriate
columns. This has not been done in the charts presented in this book, which have been
simplified to improve clarity). This also ensures that the studyman does not omit any
essential information. In figure 26 the operation just described on the chart in figure
25 is set down again.
Before we go on to discuss the uses of the flow process chart as a means of
examining critically the job concerned with a view to developing an improved method,
there are some points which must always be remembered in the preparation of process
charts. These are important because process charts are the most useful tool in the field
of method improvement; whatever techniques may be used later, the making of a
process chart is always the first step.

(1) Charting is used for recording because it gives a complete picture of what is being
done and helps the mind to understand the facts and their relationship to one
another.
(2) The details which appear on a chart must be obtained from direct observation.
Once they have been recorded on the chart, the mind is freed from the task of
carrying them, but they remain available for reference and for explaining the
situation to others. Charts must not be based on memory but must be prepared as
the work is observed (except when a chart is prepared to illustrate a proposed new
method).
(3) A high standard of neatness and accuracy should be maintained in preparing fair
96 copies of charts constructed from direct observation. The charts will be used in
 FECORD, EXAMINE, DEVELOP

Figure 25. Flow process chart: engine stripping, cleaning and degreasing

IHART No. / SHEET No.7 OF 1 METHOD: Original

TRODUCT: Bus Engines OPERATIVE (S):
LOCATION: Degreasing shop
'ROCESS: Suipping, degreasing and CHARTED BY:
cleaning used engines APPROVED BY: DATE:

)ISTANCE SYMBOL ACTIVITY TYPE OFACTIVITY

(m)
v ln old-engine stores
rc) Picked up engine by crane (electric) Non-productive
24 rQ Transported to next crane
rc) Unloaded to floor
rQ Picked up by second crane (electric)
30 rQ Transported to stripping bay
cQ Unloaded to floor
o Engine stripped . Productive
o Main components cleaned and laid out
tr Components inspected for wear; inspection report written . Non-productive
rc) Parts carried to degreasing basket
rQ Loaded for degreasing by hand-operated crane
t.5 rc) Transponed b degreaser
ro c) Unloaded into degreaser .

o Degreased Productive
,,Q Lifted out of degreaser hy crane . Non-productive
tro Transported away from degreaser
r! c) Unloaded to ground
D To cool
t2 t.o Transported to cleaning benches
o All parts completely cleaned Productive
,l+ All cleaned parts placed in one box Non-productive

D Awaiting tnnsport
r6+ All parts except cylinder block and heads loaded on trolley
76 tr+ Transported to engine inspection section
,!tr) Parts unloaded and arranged on inspection table
rrtr) Cylinder block and head loaded on trolley
76 a$ Transported to engine inspection section
,t4 Unloaded on ground
2375 E Stored temporarily awaiting inspection

(Adapted from an original)

97
 FECORD, EXAMINE, DEVELOP

Figure 26. Flow process chart-material type: engine stripping.

cleaning and degreasing (original method)

FLOW PROCESS CHART TIAT/MATER IAL/€Eg{fffi TYPE

CHART No., SHEET No. ', OF 'l s U M M A R

ACTIVITY PRESEN PROPOSED SAVING
Subisct charted:
Usad bus anginos OPEBATION O 4
TRANSPORT Q 2t
ACTIVITY: DEI.AY D 3
Sttipping. cloaning and dograasing INSPECTION D I
ptiot to inspaction sroRAGE V ,
METHOD: PRESENT/F8€fi9€Eo DISTANCE (m) 237.5
LocATloN: Daoraasno shoo flME (man-mint
OPERATIVE(S): CLOCK Nog./23 cosT
57' LABOUR
CHARTED BY: MATERIAL
APPROVED.BY: DATE: TOTAL
DIST- SYMEOL
DESCRIPTION OTY. ANCE TIME REMARKS
lml (min) o o D tr V
Storcd in old-ongina stoto
Enoina Did@d uD Elactric cnne
fnnsDonod lo nexl ctane 24
Unloadod to tloot
ksd uo
fnnsooned to sttiDDins baY 30
Unlodded to floot
Enoine striDDad
Uain comoonants cleanad and laid oul
ComDonants insDacted fot weac
inspection rcpora witten
Patts cailiad to dooraasino baskot 3
Loadad for dagrcasiig
f h n soorled to de orea ser 1.5 HEnd dane
td into deofeasef
Deorcasd
ad out ol deoreasef r
TransDorted awov ttom dagraeset 6 t
Unloaarat to ofound \
't2
t> By hand
TnnsDottad lo cleanino banches
All hans deene,l c
All cleenAd Deis Dldcad in one box 9 By hand
7 bansDorl D.
Att nun. exceo, cvtindet block and heads
loadod on t olley {
frAne^adcrl ,a anaine iasncdion saarion 7A T Irollet
Pefls unloaded and anonoed on ,nsDeclon I
tablc _t
vlinder hlock and haad loadad on trolleY I
tad to enoind insDection section 76 I Ttolloy
'Jnloaded to srcund T
vorad remdoreilv ewailino insDdction

TOTAL 237.5 4 2' 3 1 1

(Adapted from tbe original)

98
 RECORD, EXAMINE, DEVELOP

explaining proposals for standardising work or improving methods. An untidy

chart will always make a bad impression and may lead to errors.
( ) To maintain their value for future reference and to provide as complete informa-
tion as possible, all charts should camy a heading giving the following information
(see figure 26):
(a) The name of the product, material or equipment charted, with drawing
numbers or code numbers.
(D) The job or process being carried out, clearly stating the starting point and the
end point, and whether the method is the present or proposed one.
(c) The location in which the operation is taking place (department, factory, site,
etc).
(d) The chart reference number, sheet number and the total number of sheets.
(e) The observer's name and, if desired, that of the person approving the chart.
@ The date of the study.
(g) A key to the symbols used. This is necessary for the benefit of anyone who
may stufr the chart later and who may have been accustomed to using dif-
ferent symbols. It is convenient to show these as part of a table summarising
the activities in the present and proposed methods (see figure 26).
(h) A summary of distance, time and, if desired, cost of labour and material, for
comparison of old and new methods.
(5) Before leaving the chart, check the following points:
(a) Havethe facts been correctly recorded?
(b) Have any over-simplifying assumptions been made (e.g. is the investigation so
incomplete as to be inaccurate)?
(c) Have all the factors contributing to the process been recorded?
So far we have been concerned only with the record stage. We must now consider the
steps necessary to examine critically the data recorded.

2. Examine critically: the questioning technique

The five sets of activities recorded on the flow process chart fall naturally
into two main categories, namely-

tr those in which something is actually happening to the material or workpiece

under consideration, i.e. it is being worked upon, moved or examined; and
tl those in which it is not being touched, being either in storage or at a stand-
still owing to a delay. 99
 RECORD, EXAMINE, DEVELOP

Activities in the first category may be subdivided into three groups:

tr *MAKE READY" activities required to prepare the material or workpiece

and set it in position ready to'be worked on. In the example in figure 25
these are represented by the loading and transporting of the engine to the
degreasing shop, transporting it to the cleaning benches, etc.
tr "DO" operations in which a change is made in the shape, chemical com-
position or physical condition of the product. In the case of the example
these are the dismantling, cleaning and degreasing operations.
tr "PUT AWAY' activities during which the work is moved aside from the
machine or workplace. The "put away" activities of one operation may be
oomake
the ready" activities of the next-as, for example, transport between
operations from the degreaser to the cleaning benches. Putting parts into
storage, putting letters into an "Out" tray and inspecting finished parts are
other examples.
It will be seen that, while "make ready" and "put away" activities may be
represented by "transport" and "inspection" symbols, "do" operations can only be
represented by "operation" symbols.
The aim is obviously to have as high a proportion of "do" operations as
possible, since these are the only ones which carry the product forward in its progress
from raw material to completion. ('Do" operations in non-manufacturing industries
are those operations which actually carry out the activity for which the organisation
exists, for example the act of selling in a shop or the act of typing in an office.) These
are "productive" activities; all others, however necessary, may be considered as "non-
productive" (see figure 25). The first activities to be challenged must therefore be
those which are obviously "non-productive", including storages and delays which
represent tied-up capital that could be used to further the business.

THE PRIMARY OUESTIONS

The questioning sequence used follows a well established pattern which examines-
the PURPOSE for which
the PLACE at which
the activities are
the SEQUENCE in which
undertaken
the PERSON by whom
the MEANS by which
ELIMINATING
COMBINING
with a view to REARRANGING those activities.
or
SIMPLIFYING
In the first stage of the questioning technique, the Purpose, Place, Sequence,
Person, Means of every activity recorded is systematically queried, and a reason for
100 each reply is sought.
 RECORD, EXAMINE, DEVELOP

The primary questions therefore are-

What is actually done? I ELIMINATE
PURPOSE: whv is the activity necessary unnecessary parts
at all? ofthejob.
PLACE: Where is it being done? Why is
it done at that particu- COMBINE
lar place? wherever possible
SEQUENCE' rilhen isit done? Why is it or
done at that particular REARRANGE
time? the sequence of
operations for
PERSON: rilho is doing it? IVhy is it more effective
done by that particular
results.
person?
', MEANS: How is it being done? Why is SIMPLIFY
it being done in that
the operation.
particular way?

THE SECONDARY OUESTIONS

Thus, during this second stage of questioning (having asked already, about
every activity recorded, what is done and why is it done), the method study man goes
on to inquire: What else might be done? And, hence: What should be done? In the
same way, the answers already obtained on place, sequence, person and means are
subjected to further inqury.
Combining the two primary questions with the two secondary questions
under each of the headings *purpose, place", etc., yields the fotlowing list, which sets
out the questioning technique in full:

PURPOSE: What is done?

IVhy is it done?
What else might be done?
What should be done?

t Many investigators use

the question: What is actually achieved? 'lo1
 RECOBD, EXAMINE, DEVELOP

PLACE: Where is it done?

Why is it done there?
Where else might it be done?
Where should it be done?
SEQUENCE' When is it done?
Why is it done then?
When might it be done?
When should it be done?
PERSON: Who does it?
Why does that person do it?
Who else might do it?
Who should do it?
MEANS: How is it done?
Why is it done that way?
How else might it !e done?
How should it be done?
These questions, in the above sequence, must be asked systematically every
time a method study is undertaken. They are the basis of successful method study.

EXAMPLE: ENGINE STRTPPING, CLEANING AND DEGREASING

Let us now consider how the method study men who prepared the flow
process chart in figure 25 set about examining the record of facts which they had ob-
tained in order to develop a improved method. Before doing so, we shall transfer the
same record to a standard flow process chart form (figure 26) with the necessary in-
formation on the operation, location, etc., duly filled in.
This form, like all the forms in this book, is designed so that it can be
prepared on a standard typewriter. The arrangement of the symbols in the columns is
to enable those used most to be closest together.
To help the reader to visualise the operation, a flow diagram showing the
layout ofthe degreasing shop and the path taken by the engine in its journey from the
old-engine stores to the engine-inspection section is given in figure 27. It is evident
from this that the engine and its parts follow an unnecessarily complicated path.
Examination of the flow process chart shows a very high proportion of
o'non-productive" activities. There are in fact only four operations and one inspection,
while there are 2l transports and three delays. Out of 29 activities, excluding the
original storage, only five can be considered as "productive".
Detailed examination of the chart leads to a number of questions. For ex-
ample, it will be seen that an engine being transported from the old-engine stores has
to change cranes in the middle of its journey. Let us apply the questioning technique
to these first transports:

Q. What is done?
A. The engine is carried part of the way through the stores by one electric crane,
is placed on the ground and is then picked up by another which transports it to
102 the stripping bay.
 RECOBD, EXAMINE, DEVELOP

Figure 27. Flow diagram: engine stripping, cleaning and degreasing

ORIGINAL METHOD PROPOSED METHOD

Original Method

1 = Store
2 = Stripping
3 = Degreaser
4 = Cooling
5 = Cleaning
6 = Locker
7 = Tool Cabinet
8 = Paraffin Wash
9 = Charge Hand
- - - Monorail

Proposed Method
',!
A = Store
B = Engine Stand
(Stripping)
C = Basket
D : Degreaser
E = Cleaning
F - Motor
G = Locker
H = Charge Hand
| = Bench
- - - Monorail

103
 RECOBD, EXAMINE, DEVELOP

Q. Why is this done?

A. Because the engines are stored in such a way that they cannot be directly
picked up by the monorail cranb which runs through the stores and degreasing
shop.
Q. What else might be done?
A. The engines could be stored so that they are immediately accessible to the
monorail crane, which could then pick them up and run directly to the strip-
ping bay.

Q. What should be done?

A. The above suggestion should be adopted.
In the event this suggestion was adopted, and as a result three o'transports"
were eliminated (see figure 28).

Let us continue the questioning technique.

a. Why are the engine components cleaned before going to be degreased since they
are again cleaned after the grease is removed?
A. The original reason for this practice has been forgotten.
a. Why are they inspected at this stage, when it must be difficult to make a proper
inspection of greasy parts and when they will be inspected again in the engine-
inspection section?
A. The original reason for this practice has been forgotten.

This answer is very frequently encountered when the questioning technique

is applied. On many occasions, activities are carried out for reasons which are impor-
tant at the time (such as temporary arrangements to get a new shop going quickly in
the absence of proper plant and equipment) and are allowed to continue long after the
need for them has passed. Ifno satisfactory reason why they should be continued can
be given, such activities must be ruthlessly eliminated.
The next questions which arise refer to the loading into the degreaser. Here
itappears to have been necessary to transport the parts 3 metres in order to put them
into the degreaser basket. Why cannot the degreaser basket be kept near at hand?
Cannot the parts be put straight into the degreaser basket as the engine is dismantled?
The above example illustrates how the questioning technique can be applied.
The questions and answers may sometimes look rather childish as they are set out
above, but in the hands of an experienced investigator the questioning is very rapid.
Sticking to the very rigid sequence ensures that no point is overlooked. And, of
course, starting with the most searching scrutiny of the operation itself-

What is done? and Why is it necessary?

ensures that time is not wasted on details if the whole operation should not be neces-
104 sary, or if its fundamental purpose could be achieved in some better way.
 RECORD, EXAMINE, DEVELOP

Figure 28. Flow process chart-material type: engine stripping, cleaning and degreasing
(improved method)

FLOW PROCESS CHART il*fr/ MATERI AL/€€lt {+mr$ TYPE

CHART No.2 SHEET No.1 OF, s U M M A R

Subioct chartod: AC'I /ITY PRESENT PROPOSED SAVING

Used bus engines OPERATION O 4 3 I
TRANSPOFT + 21 t5 6
ACTIVIfi: DELAY D 3 2 1

Stripping, degrcasing and claaning n

TNSPECTION 1 I
prior to inspection STORAGE V 1 1 1

METHOD : Pfl€eEr{+/PROPOSED DISTANCE (m) 237.5 t 50.0 87.5

LOCATION: Deorcasing shoQ llME lman-minl
OPERATIVE(S): CLOCKNos 7234 cosT
571 LABOUR
CHARTED BY: MATERIAL
APPROVED BY: DATE: IOTAL
OTY. DIST- TIME SYMBOL
DESCRIPTION ANCE REMABKS
(m) (min)
o D D V

Slored in old-engine slore

Ensine picked up I Electic
Ttanspoiled to suipping bay 55 hoist on mono"
Unloaded on to enoine stand tatl
Engine sttipped
fransported lo degrcaset basket Bv hand
Loaded into basket Hoist
I rcnSDotted to cleoteaser
Unloaded inlo deoreaser
Degrcased
Unloaded from deoreaser
Transpoded lrcm degrcaser 4.5
Unloaded ,o otoun.l
Allowed to cool
Trcnsponed b cleaning benches 6
All pails cleaned
All Dails collected in soecial tnys 6
Awaiting transpott
Trcys and cylindq block loaded on tolley
IransDoilecl to enotne,nsDeclrcn sectlon 76 Trclley
Trays slid on to inspection benches and blocks a

on to plattom

TOTAL 150 3 t5 2 7

105
 RECOBO, EXAMINE, DEVELOP

3. Develop the improved method

There is an old saying that to ask the right question is to be half-way
towards finding the right answer. This is especially true in method study. From the
very brief example of the use of the questioning sequence given above, it will be seen
that once the questions have been asked most of them almost answer themselves.
Once the questions-

tr What should be done?

tr Where should it be done?
D When should it be done?
D Who should do it?
tr How should it be done?
have been answered, it is the job of the method study man to put his findings into
practice.
The first step in doing so is to make a record of the proposed method on a
flow process chart, so that it can be compared with the original method and can be
checked to make sure that no point has been overlooked. This will also enable a
record to be made in the "summary" of the total numbers of activities taking place
under both methods, the savings in distance and time which may be expected to
accrue from the change and the possible savings in money which will result. The im-
proved method for the example discussed is shown charted in figure 28.
' It will be seen from the summary that there have been considerable reduc-
tions in the number of "non-productive" activities. The number of "operations" has
been reduced from four to three by the elimination of the unnecessary cleaning, and
the inspection carried out directly after it has also been eliminated. "Transports" have
been reduced from 2l to 15 and the distances involved have also been cut from237.5
to 150 metres-a saving of over 37 per cent in the travel of each engine.In order not
to complicate this example, times of the various activities have not been given; but a
study of the two flow process charts will make it evident that a very great saving in the
time of operation per engine has been achieved.
No further example of a flow process chart is given in this chapter because
flow process charts will be used later in the book in association with other techniques.

106
 Chapter2
The flou,andhandling
of materials

1. Plant layout
Invariably, in conducting a method study, it becomes desirable at some
stage to look critically at the movement of men and materials through the plant or
work area and to examine the plant layout. This is so because in many factories either
the initid layout was not well thought out or, as the enterprise expanded or changed
some of its products or processes, extra machines, equipment or offrces were added
wherever space could be found. In other cases temporary arrangements may have
been made to cope with an emergency situation, such as the sudden increase in de-
mand for a certain product; but then these arrangements remain on a permanent basis
even if the situation that provoked them subsequently changes. The net result is that
material and workers often have to make long, roundabout journeys in the course of
the manufacturing process; this leads to a loss of time and energy without anything
being added to the value of the product. Improving plant layout is, therefore, part of
the job of the work study specialist.

2. Some notes on plant layout

There are four major types of layout although in practice a combination of
two or more may be found in the same planl These are shown in figure 29 and are as
follows:

I Based on a defrnition given by R. W. Mallick and A. T. Gaudreau in Plant layout and practice
(NewYork,JohnWiley, 1966). 1O7
 THE FLOW AND HANDLING OF MATEBIALS

Figure 29. Types of layout

/a/ Layout by fixed position

Work in progress on
stationary product

oo
Workers

I EquiPmentandtools

/b/ Layout by process or function

f E*f
"A"J"n EMachinas

I
/"1 x \["o*""'"
o OO

/c/ Layout by product (line layout)

()-r-]*t]=*I-+E__ o Workors 6 o

Raw material

/d/ Group layout

108 Groups of workers working on a producl

(1) Layout by fixed position. This arrangement is used when the material to be
processed does not travel round the plant but stays in one place: all the necessary
equipment and machinery is brought to it instead. This is the case when the
product is bulky and heavy and when only a few units are made at a time. Typical
examples are shipbuilding and the manufacture of diesel engines or large motors
or aircraft construction.
(2) Layout by process or function. Here all operations of the same nature are grouped
together: for example, in the garment industries all the cutting of material is car-
ried out in one area, all the sewing or stitching in another area, all the finishing in a
third area, and so on. This layout is usually chosen where a great many products
which share the same machinery are being made and where any one product has
only a relatively low volume of output. Examples are textile spinning and weaving,
maintenance workshops and the garment industries.
(3) Layout by produc! or line layout, sometimes popularly referred to as "mass
production". In this layout all the necessary machinery and equipment needed to
make a given product is set out in the same area and in the sequence of the
manufacturing process. This layout is mainly used where there is a high demand
for one or several products that are more or less standardised. Typical examples
are soft drinks bottling, car assembly and some canning operations.
(4) Layout making possible group production methods, or group layout. Recently, in
an effort to increase job satisfaction, several enterprises have arranged their
operations in a new way, with a group of workers working together on a given
product or on a part of a product and having at hand all the machinery and equip-
ment needed to complete their work. In such cases the workers distribute the work
among themselves and usually interchange jobs. Further details of this method of
production are given in Chapter 24.
With these various kinds of layout in mind, we may now analyse the flow of
materials in the plant. In some situations, rapid changes in output may be realised by
switching from one type of layout to another. This is particularly true when a shift is
made from a layout by function to a line layout for one or more products of which the
output has been increased significantly.
In most cases,however, a careful analysis of the flow is called for before
any decision is taken to change a given layout, since this is usually a costly process,
and the management has to be convinced that real savings will result before sanction-
ing the change.

3. Developing a layout
The following steps are taken when a layout for a plant or a work area is
designed:

(l) The equipment and machinery needed for processing is determined by the type of
product or products.
(2) The number of units of each machine and item of equipment needed to manufac-
ture each product is determined by the volume of expected sales (based on sales
forecasts). 109
 (3) The space requirements for machinery are determined by calculating the dimen-
sions of each machine and multiplying by the number of machines needed.
(4) Provision is made for the space needed for materials (both for raw materials and
for the storage of finished products), for goods-in-process and for material-hand-
ling equipment.
(5) Provision is made for additional space for auxiliary services (washrooms, offices,
cafeteria, etc.).
(6) The total space requirement for the plant is determined by adding the space
needed for machinery to the space needed for storage and for auxiliary services.
(7) The different departments with their respective areas are so arranged that the
most economical flow of work is achieved.
(8) The plan of the building is largely determined by the positioning of working areas,
storage areas and auxiliary services.
(9) The size and design of the site is determined by allocating additional space for
parking, receiving and shipping and landscaping.
However, a work study man is rarely called upon to make a complete
design of a plant starting from the very basic steps described above. This is more the
task of the industrial engineer or the production management specialist. It is more
common for the work study man to be faced with a problem of modifying an already
existing layout. In this case, the major issue becomes that of determining the best pos-
sible flow of work, and several diagrams can be helpful here (see figure 30).1 The use
of any of these diagrams depends on whether the flow is being studied for one product
or process or for a number of products and processes performed simultaneously.

DEVELOPING THE FLOW FOR ONE PRODUCT OR PROCESS

To develop a flow for only one product or process, it is customary to use

the flow process chart described in the previous chapter, supplementing it with a flow
diagram. The flow process chart is useful in recording travel distances and the time
taken for the various operations. Its value lies in its use as an analytical tool to ques-
tion the existing method. The flow diagram, on the other hand, is a plan (drawn sub-
stantially to scale) of the factory or the work area, correctly indicating the positions of
machines and working positions. As a result of on-the-spot observation, the paths of
movement of the product or its components are traced, sometimes using the process
chart symbols to denote the activities carried out at the various points. For example,
from a simple flow diagram drawn in a workshop to represent the movements of the
material used in the assembly and welding of legs to frames for the seats of motor
buses, it was clear at a glance that there was far too much travelling of material
between workplaces. In this particular case, and after the studyman had examined the
flow diagrams and flow process charts of these activities, the distance travelled was
reduced from 575 to L94 metres.

I Readers who wish to go into more detail in the area of plant layout are referred to Richard Muther:
Pracrical plant layout (New York-and London, McGraw-HilI, 1956) and H. B. Maynard (ed.): Industrial
1 1 O engineeriig handDoo& (New York and London, McGraw-Hill, 3rd ed., 19? t).
 THE FLOW AND HANDLING OF MATERIALS

Figure 3O. Examples of various types of flow between work stations,

including flow in a multi-storey building

I-trF* t{-*
E]

J
J

T T T
EP E* E1-*

The flow diagram can also be used for the study of movement on several
floors of a multi-storey building, as can be seen from the example given in figure 30.
Ordinary flow diagrams of each floor can, of course, be made as well. 111
 THE FLOW AND HANDLING OF MATERIALS

EXAMPLE OF THE USE OF A FLOW DIAGRAM WITH A FLOW

PROCESS CHART: RECEIVING AND TNSPECTING AIRCRAFT PARTSI
The flow diagram in figure 31 shows the original layout of the receving
department of an aircraft factory. The path of movement of the goods from the point
of delivery to the storage bins is shown by the broad line. It will be noticed that the
symbols for the various activities (see Chapter 8) have been inserted at the proper
places. This enables anyone looking at the diagram to imagine more readily the acti-
vities to which the goods are subjected.

tr RECORD
The sequence of activities is one of unloading from the delivery truck cases
containing aircraft parts (which are themselves packed individually in cartons), check-
ing, inspecting and marking them before putting them into store. These cases are slid
down an inclined plane from the tail of the truck, slid across the floor to the "unpack-
ing space" and there stacked one on top of another to await opening. They are then
unstacked and opened. The delivery notes are taken out and the cases are loaded one
at a time on a hand truck, by which they are taken to the reception bench. They are
placed on the floor beside the bench. After a short delay they are unpacked; each
piece is taken out of its carton and checked against the delivery note. It is then
replaced in its carton; the cartons are replaced in the case and the case is moved to the
other side of the receiving bench to await transport to the inspection bench. Here the
case is again placed on the floor until the inspectors are ready for it. The parts are
again unpacked, inspected, measured and replaced as before. After a further short
delay the case is transported to the marking bench. The parts are unpacked, numbered
and repacked in the cartons and the case, which after another delay is transported by
hand truck to the stores and there placed in bins to await issue to the assembly shops.
The complete sequence has been recorded on a flow process chart (figure 32).

D EXAMINE critically
A study of the flow diagram shows immediately that the cases take a very
long and roundabout path on their journey to the bins. This could not have been seen
from the flow process chart alone. The chart, however, enables the vanous activities
to be recorded and summarised in a manner not conveniently possible on the diagram.
A critical examination of the two together, using the questioning technique,
at once raises many points which demand explanation, such as:

Q. Why are the cases stacked to await opening when they have to be unstacked in 10
minutes?
A. Because the delivery truck can be unloaded faster than work is cleared.
Q. What else could be done?
A. The work could be cleared faster.

rThis example has been taken, with some adaptation, from Simpli/ication du travail (the French
version of a handbook produced by the Nortir American Aviation Company Inc., Texas Division) (Paris, Editions
112 Hommes etTechniques, 2nd ed., 1950).
 THE FLOW AND HANDLING OF MATERIALS

Figure 37. Flow diagram: inspecting and marking incoming parts (original method)

-----1 --l*"a* ___]x'_c::'::

tr"*r I n

= ![[:il[l
il
I

113
 THE FLOW AND HANDLING OF MATERIALS

Figure 32. Flow process chart: inspecting and marking incoming parts (original method)

FLOW PROCESS CHART H*et/ MATE R rAL/ae{nFffifl+ TY PE

CHART No.J SHEET No., OF , U M M A R Y

Subjoct chaned: ACT IVITY PRESENT PROPOSED SAVING
(r,se of BX {C7 lce-pleccs (10 Ft cosc la codons)
OPERANON O 2
TRANSPORT + ll
ACTIVITY: Rccclve. chccl,
,ca-Prcc6 ond srore ld cor€
lnspecl ond oumbct DELAY D I
TNSPECTTON D 2
STORAGE V I
METHOD : PRESENTF*OPO0EF DISTANCE (m) 56.2
L\JLA r tVN: Kecetytnq WoL r rME (man-h.) 1 .vh
OPERATIVE(S): CLOCK No. cosr
Sec Remorks columa LABOUR $10:
BY:
CHARTED DATE: MATERIAL
APPROVEDBY: DATE: TOTAL s10.19

Qw. DIST. TIME SYMBOT

DESCRIPTION ANCE REMARKS
, cdse (m) {min) o o n V
Lilted lrcm ttuck: placecl on inclined plane t.2l 2 lobourers
Slid on inclined plane 6l lo 2
slid to stonse and stacked 6l 2
Await unpacking 30
Case unstacked ,l
Lid removed: delivatv note taken out I 5 2,,
Placod on hand truck ,l
f,,'-L6l i^ .a^66r;^h haa-h

Await discharue hom ttuck 10

Case placod on bench 2 2,.
Canons lakan lrom case: opened: checked
rcDlaced contents t5 5rorekeeper
Case loaded on hand truck 2 2 lobourers
Delay awaiting trcnsDort J
Trucked to inspection bench 16.5 10 1 lobouret
Await inspaction 10 (,a<e an lnrlt
feo-piecbs rcmoved frcm case and cartons: 1 ZO lnsDeclor
inspected to dnwing: rcplaced
Await trunspott laboutot 5 Cose on lruck
Itucked to numbeing bonch I 5
Awdit numbeilno Cose on lruck
Tae-piocai withdrawn ftom case and canons: ,5 \lorcs lohourer
numbercd on bonch and replacod
Await transDort laboutet 5 Cose on truck
Tnnspoied to disttibution point 4.5 5 1 lobourer
Storcd

TOTAL 56.2 t74 2 l1 7 2 I

114
Q. Why are the reception, inspection and marking points so far apart?
A. Because they happen to have been put there.

Q. Where else could they be?

A. They could be all together.
Q. Where should they be?
A. Together at the present reception point.
Q. Why does the case have to go all round the building to reach the stores?
A. Because the door of the stores is located at the opposite end from the delivery
point.
No doubt the reader who examines the flow diagram and the flow process
chart carefully will find many other questions to ask. There is evidently much room
for improvement. This is a real-life example of what happens when a series of activities
is started without being properly planned. Examples with as much waste of time and
effort can be found in factories all over the world.
tr DEVELOP the improved method
The solution arrived at by the work study men in this factory can be seen in
figures 33 and 34. It is clear that among the questions they asked were those sug-
gested above, because it will be seen that the case is now slid down the inclined plane
from the delivery truck and put straight on a hand truck. It is transported straight to
the'oUnpacking space", where it is opened while still on the truck and the delivery
note is taken out. It is then transported to the reception bench, where, after a short
delay, it is unpacked and the parts are put on the bench. The parts are counted and
checked against the delivery note. The inspection and numbering benches have now
been placed beside the reception bench so that the parts can be passed from hand to
hand for inspection, measuring and then numbering. They are finally replaced in their
cartons and repacked in the case, which is still on the truck.
It is evident that the investigators were led to ask the same question as we
asked, namely: "Why does the case have to go all round the building to reach the
stores?" Having received no satisfactory answer, they decided to make a new
doorway into the stores opposite the benches, so that the cases could be taken in by
the shortest route.
It will be seen from the summary on the flow
process chart (figure 34) that
the'oinspections" have been reduced from two to one, the "transports" from eleven to
six and the'odelays" (or temporary storages) from seven to two. The distance trav-
elled has been reduced from 56.2 to 32.2 metres.
The number of man-hours involved has been calculated by multiplying the
ootrucked
time taken for each item of activity by the number of workers involved, e.g.
to reception bench" : 5 minutes x 2labourers: 10 man-minutes. Delays are not in-
cluded as they are caused by operatives being otherwise occupied. In the improved
method the inspector and stores labourer are considered to be working simultaneously
on inspecting and numbering respectively, and the 20 minutes therefore becomes 40
man-minutes. Labour cost is reckoned at an average at an average of US$ 5.20 per
hour for all labour. The cost of making a new doorway is not included, since it will be
spread over many other products as well. 115
 THE FLOW AND HANDLING OF MATERIALS

Figure 33. Flow diagram: inspecting and marking incoming pans (improved method)

TRUCl(

f_l,.^,.,
UNPACKING SPACE

.
-,jvna- - - - - - : -- O ttr- -P

!E\[ilII
ff"
I!'.H!1
!l rn tl
116
 THE FLOW AND HANDLING OF MATERIALS

Figure 34. Flow process chart: inspecting and marking incoming parts (improved method)

FLOW PROCESS CHART +tt*Ni/ M AT E B I A L/€€*nFfiEll+ TY P E

CHART No.4 SHEET No. t OF, SU MMA RY

Subjoct chaned: ACTIVITY PRESENT PROPOSED SAVING
Case ol BX 487 tee-pieces (fO per case in cartons) oPERATTON O 2 2
TRANSPORT O 1l 6 5
ACTIVITY: Receive, check. inspect and numbet DELAY D 7 2 5
tee-pieces: storc in case TNSPECION n 2 I ,
SToRAGE V I 1

M ETH OD. 1trH+SEII+/PRO POSED DISTANCE (ml 56.2 32.2 24

LOCATION: Receivind DeDt. TIME (man-h.) 1.96 t.16 o.ao
OPERATIVE(S) CTOCK No. COST per cosc
See Remarks column TABOUR $ro: s6:3 $n.ru
CHAFTED BY: DATE: MATERIAL
APPROVED BY: DATE: TOTAL 810.19 $6.03 94.16
DIST.
DESCRIPTION QTY. ANCE TIME SYMBOL REMARKS
I cose (m) (min) o o D n 17

Crcte lifted ftom truck: placed on inclined plane

Slid on inclined plane -41 2 labourers
2,,
Placed on hand truck 1l 2
t tucKed to unpacking space 6 5 I lobourct
Lid laken off case 5
ftucked to rcceivino behch I
Await unloading 5
Cartons taken from case: opened and tee-pieces
I
placed bench: counted and inspected t 20 lnsDeclot
I
to drcwing I
Numbered and teplaced in case Slores lobourer
Await transport labourcr
Trucked to distribution point I 5 1 lobourer
Storcd

TOTAL 32,2 55 2 6 2 I 1

117
 THE FLOW AND HANDLING OF MATEBIALS

DEVELOPING THE FLOW FOR A NUMBER OF PRODUCTS OR PROCESSES

If several products are being made or several processes are being carried
out at the same time, another type of chart is used to determine the ideal placing of the
machinery or operations. This is the cross charl
As can be seen from figure 35, the cross chart is drawn up by listing the
various operations (or machinery) through which the different products pass at the
various stages of production, on both the horizontal and vertical dimensions of the
chart. The example in frgure 35 illustrates the use of the cross chart for a company
making decorated metal products. In this case, the company is producing 70
products, each of which passes through some of the operations indicated.
To complete this chart, take one product at a time and enter its sequence of
manufacturing in the appropriate square on the chart. If a product moves from
"Form" to "Normalise", a stroke is made in the square "Form/Normalise". If it sub-
sequently moves from 'oNormalise" to "Plate", a stroke is entered in the correspond-
ing square, and so on until the whole sequence of operations for that particular pro-
duct is entered. The same process is then repeated for each of the other 70 products.
The completed cross chart will appear as in figure 35.
The next step is to decide which operations should be placed adjacent to
each other. From the chart it is clear that 27 products out of 70 (i.e. 39 per cent of the
products) pass directly from "Form" to "Pack and ship". These two operations
should therefore be adjacent. Similarly, all22 products that were subjected to plating
passed from ooPlate" to "Coat" and from "Coat" to o'Polish". Hence, these three
operations should follow each other in sequence. By following the same line of reason-
ing it is possible to reach the preferred sequence of operations.
A variation on this technique is to complete the cross chart by taking a sam-
ple of the most frequently produced items. If the plant is producing over 100 different
items, it may become cumbersome to follow the method indicated above. However, in-
vestigation may reveal that, say, 15 or 20 items account for possibly 80 per cent of the
production volume. The sequence of operations of these items would then be entered
on the cross chart, and the flow determined in the same way as that described above.

VISUALISING THE LAYOUT

Once the dimensions and the relative position of machinery, storage facili-
ties and auxiliary services have been determined, it is advisable to make a visual pre-
sentation of the proposed layout before proceeding with the actual rearrangement of
the workplace, which may be a costly operation. This can be done by the use of
'otemplates", or pieces of cardboard cut out to scale. Different coloured cards may be
used to indicate different items of equipment, such as machines, storage racks,
benches or material-handling equipment. When positioning these templates, make sure
that gangways are wide enough to allow the free movement of material-handling
equipment and goods-in-process.
Alternatively, scale models may be used to provide a three-dimensional dis-
play of the layout. Various types of model for many well-known items of machinery
and equipment are readily available on the market and are particularly useful for
118 training purposes.
 IHE FLOW AND HANDLING OF MATERIALS

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119
 MATERIALS

4. The handling of materials

A good deal of time and effort is often expended in moving material from
one place to another in the course of processing. This handling is costly and adds
nothing to the value of the product. In essence, therefore, there should ideally be no
handling at all. Unfortunately this is not possible. A more realistic aim would be to
move material by the most appropriate methods and equipment at the lowest possible
cost and with regard to safety. This aim may be met by-

D eliminating or reducing handling;

fl improving the efficiency of handling;
tr making the correct choice of material-handling equipment.

ELIMINATING OR REDUCING HANDLING

There is often ample scope for eliminating or reducing handling. [n practice,

it becomes obvious that there is a need to improve an existing situation when certain
symptoms are observed, e.g. too much loading and unloading, repeated manual hand-
ling of heavy weights, material travelling considerable distances, non-uniform flow of
work with congestion in certain areas, frequent damage or breakage resulting from
handling, and so on. These are some of the most frequent phenomena that invite the
intervention of the work study specialist. The approach to be followed here is similar
to the traditional method study approach, using outline and flow process charts and
flow diagrams and asking the same questions as to o'where, when, who, how" and,
above all, "why" this handling is done.
However, such a study may frequently have to be preceded by or carried
out in conjunction with a study of the layout of the working area, in order to reduce
movement to a minimum.

TMPROVING THE EFFICIENCY OF HANDLING

The observance of certain precepts can improve the efficiency of handling.

These precepts are-
( 1) Increase the size or number of units being handled at any one time. If necessary,
review product design and packaging to see if you can achieve this result more
readily.
(2) Increase the speed of handling if this is possible and economical.
(3) Let gravity work for you as much as possible.
(4) Have enough containers, pallets, platforms, boxes, etc., available in order to make
transportation easier.
(5) Give preference in most cases to material-handling equipment that lends itself to a
variety of uses and applications.
(6) Try to ensure that materials move in straight lines as much as possible, and ensure
120 that gangways are kept clear.
MAKING THE CORRECT CHOICE OF HANDLING EOUIPMENT
The work study man should be aware of the different kinds and types of
material-handling equipment. Although there are literally hundreds of various types,
these may be classified in four major categories.

tr CONVEYORS
Conveyors are useful for moving material between two fxed work stations,
either continuously or intermittently. They are mainly used for continuous or mass
production operations-indeed, they are suitable for most operations where the flow
is more or less steady. Conveyors may be of various types, with either rollers, wheels
or belts to help to move the material along: these may be power-driven or may roll
freely. The decision to provide conveyors must be taken with care, since they are
usually costly to install; moreover, they are less flexible and, where two or more con-
verge, it is necessary to co-ordinate the speeds at which the two conveyors move.

tr INDUSTRIAL TRUCKS
Industrial trucks are more flexible in use than conveyors since they can
move between various points and are not permanently fixed in one place. They are
therefore most suitable for intermittent production and for handling various sizes and
shapes of material. There are many types of truck-petrol-driven, electric, hand-
powered, and so on. Their greatest advantage lies in the wide range of attachments
available; these increase the trucks' ability to handle various types and shapes of
material.

tr CRANES AND HOISTS

The major advantage of cranes and hoists is that they can move heavy
material through overhead space. However, they can usually serve only a limited area.
Here again, there are several types of crane and hoist, and within each type there are
various loading capacities. Cranes and hoists may be used both for intermittent and
for continuous production.

tr CONTAINERS
These are either "dead" containers (e.g. cartons, barrels, skids, pallets)
which hold the material to be transported but do not move themselves, or "live" con-
tainers (e.g. wagons, wheelbarrows). Handling equipment of this kind can both con-
tain and move the material, and is usually operated manually.
Figure 36 shows some types of material-handling equipment.

The choice of material-handling equipment is not easy. In several cases the

same material may be handled by various items of equipment (see figure 37). Nor
does the great diversrry of equipment available make the problem any easier. In
several cases, however, the nature of the material to be handled does narrow the
choice.
Among the most important factors to be taken into consideration when
choosing material-handling equipment are the following: 121
 THE FLOW AND HANDLING OF MATERIALS

Figure 36. Different types of material-handling eguipment

Conveyor

Fork-lift industrial truck

CONTAINERS

Skid ("dead" container)

Trolley for ceramics or Pastries

122 ("live" container)
 THE FLOW AND HANDLING OF IVIATERIALS

Figure 37. Different possibilities of handling the same obiect

123
 THE FLOW AND HANDLING OF MATERIALS

(l) Properties of the material. Whether it is solid, liquid or gas, and in what size,
shape and weight it is to be moved, are important considerations and can already
lead to a preliminary elimination from the range of available equipment under
review. Similarly, if a material is fragile, corrosive or toxic this will imply that cer-
tain handling methods and containers will be preferable to others.
(2) Layout and characteristics of the building. Another restricting factor is the
availability of space for handling. Low-level ceilings may preclude the use of
hoists or cranes, and the presence of supporting columns in awkward places can
limit the size of the material-handling equipment. If the building is multi-storeyed,
chutes, or ramps fcr industrial trucks, may be used. Finally, the layout itself will
indicate the type of production operation (continuous, intermittent, fixed position
or group) and can already indicate some items of equipment that will be more
suitable than others.
(3) Production flow. If the flow is fairly constant between two fixed positions that are
not likely to change, fixed equipment such as conveyors or chutes can be success-
fully used. If, on the other hand, the flow is not constant and the direction changes
occasionally from one point to another because several products are being
produced simultaneously, moving equipment such as trucks would be preferable.
(4) Cost considerations. This is one of the most important considerations. The
above factors can help to narrow the range of suitable equipment. Costing can
help in taking a final decision. Several cost elements need to be taken into con-
sideration when comparisons are made between various items of equipment that
are all capable of handling the same load. There is the initial cost of the equip-
ment, from which one can derive the investment cost in terms of interest payment
(i.e. if the company has to borrow money to buy the equipment) or opportunity
costs (i.e. if the company possesses the funds and does not have to borrow, but the
purchase of the equipment would deprive it of an opportunity to invest the funds
at a certain rate of return). From the cost of the equipment one can also calculate
the depreciation charges per year, to which will be added other charges such as in-
surance, taxes and additional overheads. Apart from these fixed charges, there are
also operating costs, such as the cost of operating personnel, power, maintenance
and supervision. By calculating and comparing the total cost for each of the items
of equipment under consideration, a more rational decision can be reached on the
most appropriate choice.

124
 Ghaptef rc
Movement of workers
in theworkingarca
'! . Factory layout and the movements of workers and material
There are many types of activity in which workers move at irregular inter-
vals between a number of points in the working area, with or without material. This
situation occurs very often in industry and commerce and even in the home. In
manufacturing concerns it occurs when-
bulk material is being fed to or removed from a continuous process, and is
stored around the process;
an operative is looking after two or more machines;
labourers are delivering materials to or removing work from a series of
machines or workplaces.
Outside manufacturing operations, examples of its occurrence are-
in stores and shops where a variety of materials are being removed from or
put away into racks or bins;
in restaurant and canteen kitchens during the preparation of meals;
in control laboratories where routine tests are carried out at frequent inter-
vals.

2. The string diagram

One technique for recording and examining this form of activity is the string
diagram. It is one of the simplest of the techniques of method study and one of the
most useful.

The string diagram (see Frgure 38) is thus a special form of flow diagram, in
which a string or thread is used to measure distance. Because of this it is necessary
that the string diagram be drawn correctly to scale, whereas the ordinary flow 125
 MOVEMENT OF WORKEBS IN THE WOBKING ABEA

Figure 38. A string diagram

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4
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N
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diagram will probably be drawn only approximately to scale, with pertinent distances
marked on it so that scaling off is unnecessary. The string diagram is started in exact-
ly the same way as all other method studies: by recording all the relevant facts from
direct observation. Like the flow diagram, it will most often be used to supplement a
flow process chart, the two together giving the clearest possible picture of what is ac-
tually being done. As always, the flow process chart will be examined critically in
order to make sure that all unnecessary activities are eliminated before a new method
is developed.
A string diagram can be used to plot the movements of materials, and this is
sometimes done, especially when a work study man wants to find out easily just how
far the materials travel. We could have constructed a string diagram for each of the
examples in the last chapter, but this was not necessary. The simple flow diagram
showed all that was needed, and was quicker to prepare for the circumstances illus-
trated. The string diagram is most often used, however, for plotting the movements of
workers, and it is this application which is considered in the examples given in the
present chapter.
The work study man proceeds to follow the worker in whom he is interested
as he moves from point to point in doing his job. (If the working area is a fairly small
one and he can see the whole of it from one point, he can watch the worker without
moving.) The studyman notes methodically each point to which the worker moves
and, if the journeys are fairly long, the times of arrival and departure. It will save a
good deal of writing if the observer codes the various machines, stores and other
126 points of call by numbers, letters or other means.
 MOVEMENT OF WORKEBS IN THE WOBKING AREA

Figure 39. Simple movement studY sheet

MOVEMENT STUDY SHEET

SHEET No. I OF 2 OPERATIVE(S):

OPERATION : Tronsport biscuil liles
from inspeclion to sloroge bins CHARTED BY:
unlood inlo bins DATE:
LOCATION : Biscuil worehouse CROSS.REFERENCE:
1ond2
4 5

MOVE TO NOTES

lnspeclion bench (l)

to Bin 4

t13
r5
r32
I18

The form of study sheet required is very simple. A sample of the headings
required is given in flrgure 39. Continuation sheets need only give columns 1,2,3, 4
and 5.
The recording of movements will continue for as long as the work study
man thinks is necessary to obtain a representative picture of the worker's movements,
which may be a few hours, a day, or even longer. The studyman must be sure that he
has noted all the journeys made by the worker and has seen them made enough times
to be sure of their relative frequency. Insuflicient study may produce a misleading pic-
ture, since the work study man may only have watched the worker during a part of
the complete cycle of activities when he was using only a few of his various paths of
movement. Later in the cycle he may not use these at all but use others a great deal.
Once the studyman is satisfied that he has a true picture-which should be checked
with the worker concerned to make sure that there is nothing else which is usually
done that has not been observed-the string diagram may be constructed.
A scale plan of the working area similar to that required for a flow diagram
must be made (the same plan may be used so long as it has been accurately drawn). 127
 Machines, benches, stores and all points at which calls are made should be drawn in
to scale, together with such doorways, pillars and partitions as are likely to affect
paths of movements. The completed plan should be attached to a softwood or com-
position board, and pins driven into it flrmly at every stopping point, the heads being
allowed to stand well clear of the surface (by about 1 cm). Pins should also be driven
in at all the turning points on the route.
Ameasured length of thread is then taken and tied round the pin at the
starting point of the movements (the inspection bench (I) in figure 38). It is then led
around the pins at the other points of call in the order noted on the study sheet until all
the movements have been dealt with.
The result is an over-all picture of the paths of movement of the operative,
those which are most frequently traversed being covered with the greatest number of
strings, the effect being as in figure 38.
It will be seen from the sketch that certain paths-in particular those
between A and D, A and H, and D and L-are traversed more frequently than the
others. Since most of these points are at a fair distance from one another, the diagram
suggests that critical examination is called for, with a view to moving the work points
which they represent closer together.
It will be remembered that the thread used was measured before the
studyman started to make the diagram. By measuring the length remaining and sub-
tracting this from the total length, the length used can be found. This will represent, to
scale, the distance covered by the worker. If two or more workers are studied over the
same working area, different coloured threads may be used to distinguish between
them.
The examination of the diagram and the development of the new layout can
now proceed on the same lines as with a flow diagram, with templates being used and
the pins and templates being moved around until an arrangement is found by which
the same operations can be performed with a minimum movement between them. This
can be ascertained by leading the thread around the pins in their new positions,
starting from the same point and following the same sequence. When the thread has
been led around all the points covered by the study, the length left over can again be
measured. The difference in length between this and the thread left over from the
original study will represent the reduction in distance travelled as a result of the
improved layout. The process may have to be repeated several times until the best
possible layout (i.e. the layout with which the minimum length of thread is used) is
achieved.
The string diagram is a useful aid in explaining proposed changes to
management, supervisors and workers. If two diagrams are made, one showing the
original layout and one the improved layout, the contrast is often so vivid-particular-
ly if brightly coloured thread is used-that the change will not be difficult to 'osell".
Workers especially are interested in seeing the results of such studies and discovering
how far they have to walk. The idea of reducing one's personal effort appeals to
almost everyone!
The following example shows this technique as applied to the movements of
128 labourers storing tiles after inspection.
 MOVEMENT OF WORKERS IN THE WORKING ABEA

EXAMPLE OF A STRING DIAGRAM: STORING TILES AFTER TNSPECTION

! RECORD
In the operation studied in this example, 'obiscuit" tiles (i.e. tiles after first
hring and before glazing) are unloaded from kiln trucks on to the bench, where they
are inspected. After inspection they are placed on platforms according to size and
type. The loaded platforms are taken on hand-lift trucks to the concrete bins where the
tiles are stored until required for glazing. The original layout of the store is shown in
flrgure 40.
It was decided to make a study using a string diagram to find out whether
the arrangement, which appeared to be a logical one, was in fact the one involving the
least transport. Studies were made of a representative number of kiln truck loads. This
was because the types of tile on each truck varied somewhat, although l0 cm x l0 cm
and I 5 cm x 15 cm plain tiles formed by far the largest part of each load.
A form of the type shown in figure 39 above was used for recording the in-
formation. Only a portion is shown, since the nature of the record is obvious. (The bin
numbers are those shown in figure 40.)
It will be seen that, in this case, times were not recorded. It is more useful to
record times when long distances are involved (such as in trucking between depart-
ments of a factory).
The string diagram was then drawn up in the manner shown (figure 40).
The width of the shaded bands represents the number of threads between any given
points and hence the relative amount of movement between them.

tr EXAMINE critically
A study of the diagram shows at once that the most frequent movement is
up the l0 cm x l0 cm and 15 cm x 15 cm rows of bins. The bin into which any par-
ticular load of tiles is unloaded depends on which are full or empty (tiles are con-
stantly being withdrawn for glazing). Travel in the case of the 10 cm x l0 cm and
15 cm x 15 cm tiles may therefore be anywhere up or down the rows concerned.
It is equally obvious that the "special feature" tiles (used for decorative pur-
poses in comparatively small numbers) are handled only rarely, and are generally
placed by the inspectors on one truck and delivered to several bins at once. Deliveries
of tiles other than those mentioned are fairly evenly distributed,

tr DEVELOP the new layout

The first step in developing the new layout is to locate the bins containing
the most handled tiles as near as possible to the inspection bench and those containing
"special feature" tiles as far away as possible. This certainly spoils the tidy sequence
and may, for a time, make tiles a little more diffrcult to rmd; however, the bins, which
have concrete partitions between them about 1 metre high, can carry cards with the
contents marked on them. The cards can be seen from a distance, and the arrange-
ment will soon be memorised by the workers. After a number of arrangements had
been tried out, the one shown in figure 41 proved to be the most economical of trans-
port time. The distances covered were reduced from 520 to 340 metres, a saving of
35 per cent. 129
 MOVEMENT OF WORKERS IN THE WORKING AREA

Figure 4O. String diagram: storing tiles (original method)

32
20x20
REICORNER

31

20,2o
PLAIN

30
222
l0 cm STRIP a
J
&

o
29
z
15x8 a
RE J
L
o
o
2A
I 5xB

27
15x10
RE

26
15'10
PLAIN

25
15x15
CORNERS

130
 MOVEMENT OF WORKERS IN THE WORKING AREA

Figure 41. String diagram: storing tiles (improved method)

SINGLE JOURNEY SINGLE JOURNEY

38
'10x5
RE

131
 3. The man type flow process chart
In table 9 in Chapter 8 five different types of process chart were listed. The
outline process chart was described in Chapter 8, and the two-handed process chart
will be dealt with in Chapter 11. The other three are flow process charts:
Flow process chart-man tYPe
Flow process chart-material tYPe
Flow process chart-equipment type
Several examples of material type flow process charts have already been
given (figures 26 and 28 in Chapter 8; figures 32 and 34 in Chapter 9). We shall now
deal with man type flow process charts.

The same techniques as have been used to follow materials through the
operations and movements which they undergo can be used to record the movements
of a man. Man type flow process charts are frequently used in the study ofjobs which
are not highly repetitive or standardised. Service and maintenance work, laboratory
procedure and much of the work of supervisors and executives can be recorded on
charts of this type. Since the charts follow one individual or a group performing the
same activities in sequence, the standard flow process chart forms can be used. It is
usually essential to attach to the man type flow process chart a sketch showing the
path of movement of the worker while he is carrying out the operation charted.
The charting procedure used in compiling a man type flow process chart is
almost exactly the same as that used on material type flow process charts. There is
one slight difference however-a useful charting convention which helps to distinguish
man type charts from the other two flow process charts, and which will be found quite
natural in practice.
The definition of the man type chart given above states that it records what
the worker does. The definitions of the other two flow process charts, however, state
that they record (material type) how material is handled or treated, and (equipment
type) how the equipment is used. The definitions thus reflect the charting practice,
which is to use mainly the active voice on man type charts, and mainly the passive
voice on the other two. The convention, which has been followed on all the flow
process charts illustrated in this book, will be clear from the following examples of
typical entries:
Flow Process Charts
Man type Material type

Drills casting Casting drilled

Carries to bench Carried to bench
Picks up bolt (bolt) Picked up
132 lnspects for finish Finish inspected
 MOVEMENT OF WORKERS IN THE WORKING AREA

An example of a man type flow process chart applied to hospital activities

is given below.

EXAMPLE OF A MAN TYPE FLOW PROCESS CHART:

SERVING DINNERS IN A HOSPITAL WARD
t] RECORD
Figure 42 shows the layout of a hospital ward containing 17 beds. When
dinners were served by the original method, the nurse in charge of the ward fetched a
large tray bearing the first course, together with the plates for the patients, from the
kitchen. The food was usually contained in three dishes, two of which held vegetables
and the third the main dish. The nurse placed the tray on the table marked "Serving
Table" in the diagram. She set the large dishes out on the table, served one plate with
meat and vegetables and carried it to bed 1. She returned to the serving table and
repeated the operation for the remaining 16 beds. The paths which she followed are
shown by the full lines in the diagram. When she had served all the patients with the
first course, she returned to the kitchen with the tray and the empty dishes, collected
the dishes and plates for the second course and returned to the ward. She then
repeated the complete operation, replacing the plates emptied by the patients with
plates containing their portions ofthe second course and returning the used plates to
the serving table, where she stacked them. Finally she made a tour of the ward, col-
lecting up the empty plates from the second course, and carried everything on the tray
back to the kitchen. (To avoid confusion on the diagram, the final collection of empty
plates is not shown. In both the original and the improved method the distance
covered and the time taken are the same, since it is possible for her to carry several
plates at a time and move from bed to bed.) The operation has been recorded in part
on the flow process chart in figure 43 but only enough has been shown to demonstrate
to the reader the method of recording, which it will be seen is very similar to that used
for material type flow process charts, bearing in mind that it is a person and not a
product that is being followed. As an exercise the reader may wish to work out the
serving cycles for himself on the basis provided by the diagram. The dimensions of the
ward are given. It is, of course, possible to complete the man type flow process chart
in much greater detail if desired.

U EXAMINE critically
A critical examination of the flow process chart in conjunction with the
diagram suggests that there is considerable room for improvement. The first ooWhy?"
which may come to mind is: *Why does the nurse serve and carry only one plate at a
time? How many could she carry?" The answer is almost certainly: "At least two." If
she carried two plates at a time, the distance she would have to walk would be almost
halved. One of the first questions asked would almost certainly be: "Why is the serv-
ing table there, in the middle of the ward?" followed, after one or two other questions,
by the key questions: "Why should it stand still? Why can it not move round? Why
not a trolley?" This leads straight to the solution which was adopted.

tr DEVELOP the new method

It will be seen from the broken line in the diagram (representing the revised
path of movement of the nurse when provided with a trolley) and from the flow 133
 MOVEMENT OF WORKEBS IN THE WORKING AREA

Figure 42. Flow diagram: serving dinners in a hospital ward

11.5
METRES

I
!

ABLE

r--1
lcl
l'l
l-rJ
L\
tT' i
I
I
t il t
iL
\
- \ --l

lr
ooon Q
ORIGINAL METHOD
I kiichan 1 2 matres from doot
I
IMPROVED METHOD I
----

134
 MOVEMENT OF WOFKERS IN THE WOBKING AREA

Figure 43. Flow process chart-man type: serving dinners

in a hospital ward

FLOW PROCESS CHART M AN /i,I*FEFI*LI€€XJ{+HII+ TY PE

CHART No.7 SHEET No. 7 OF I SU MM RY

Subjact chartsd: ACTIVITY PRESENT PBOPOSED SAVING
Hospital nu6e oPERATON o 34 t8 t6
TRANSPORT O 60 ,: (-12)
ACTIVITY: DELAY D
Serue dinnerc to t7 patients TNSPECT|ON E
STORAGE V
METHOD : PRESENT/PROPOSED DISTANCE (m) 436 197 239
TIME (man-h) 39 2A
OPERATIVE(S): CLOCK No. COST:
LABOUR
CHARTED BY: DATE: MATEBIAL r/Iro s24
APPROVED BY: DATE: TOfAL lCaDital) $24
DIST- SYMBOL
DESCRI PTION OTY. ANCE TIME REMARKS
ORIGINAL METHOD ,latel (m) (min) C $ D u V
fransports litst coutse and Dlates - Awkwad load
kitchen to setvino table on trev I ,6 .50
,'laces ct$hes and Dlales on table I .30
Setves hom thrce dishes to plaae .25
Cafiies Dlate to bed 't and rctun 7.3 25
Serves 25
Carios Dlate to bed 2 and retuh I 6 2i
J.erves 25
(conttnues unttl ail I 7 beds arc sorued. See
fiourc 32 lot
Setvice comDleted. olaces dishes on trdv
and rctums to kitchen .50
fobl disldnce and time. first cvcle 192 10 71 1 20
REPEATS CYCLE FOR SECOND COURSE 192 10.71 t7 20
Collects empty second coutso plates 52 2.0
TOfAI t36 34 t;0
IMI'HOVED METHOD
TrunsDorTs fitst coutse and nlatqs Seruing
k i t! E!J9-p9!4!9!4 -! elby t7 16 .50 trclley
Setves two Dlates 40
9q!ej!ye!!aL9t!o bed 1; leaves one: 1.5 |
cailies one plate ttom bed I to bod 2, 2 lo.6 .25
returns to posilion A Trg,I
Pushes trclley to position B 3.O
.40
Canies two Dlates to bed 3: leaves one: t5
cafiies one plate hom bed 3 to bed 4: 2 .25
rc!q!!!L9_p9t!!o! t 1.5 I
(Continues until all 17 bads arc seNed. SeA
lisurc 32 and note vatiation at
bed 11
Retuns to kitchen with ttolley 16 .50
fobl distance aid time, first cvcle 72.5 /.49 9 26
REPEA|S CYCLE FOR SECOND AOIIRSF 72.5 7.49 26
Collocts empty second cource plates 52 200 20

TOTAL 197 16.98 t8 72

135
 MOVEMENT OF WORKERS IN THE WORKING AREA

process chart that the final solution involves the nurse in serving and carrying two
plates at a time (which also saves a small amount of serving time).
The result, as will be seen from the process chart, is a reduction of over 54
per cent in the total distance walked in serving and clearing away the dinners (the sav-
ing is 65 per cent if the distance walked in removing the second-course plates, which
is the same in both the old and the new methods, is excluded).
What is important here is not so much the reduction in cost, which is very
small, as the fact that the nurse's fatigue, resulting from the considerable distance
which she had to walk within the ward and while carrying the loaded tray to and from
the kitchen, is lessened.

4. The multiple activity chart

We come now to the first of the charts listed in table 9 which use a time
scale-the multiple activity chart. This is used when it is necessary to record on one
chart the activities of one subject in relation to another.

By using separate vertical columns, or bars, to represent the activities of dif-

ferent operatives or machines against a common time scale, the chart shows very
clearly periods of idleness on the part of any of the subjects during the process. A
study of the chart often makes it possible to rearrange these activities so that such in-
effective time is reduced.
The multiple activity chart is extremely useful in organising teams of
operatives on mass-production work, and also on maintenance work when expensive
piant cannot be allowed to remain idle longer than is absolutely necessary. It can also
Le used to determine the number of machines which an operative or operatives should
be able to look after.
In making a chart, the activities of the different operatives or of the different
operatives and machines are recorded in terms of working time and idle time. These
times may be recorded by ordinary wristwatch or by stop-watch, according to the
duration of tt various periods of work and idleness (i.e. whether they are a matter of
"
minutes or seconds). Extreme accuracy is not required, but timing must be accurate
enough for the chart to be effective. The times are then plotted in their respective
columns in the manner shown in figure 44.
136 The use of the multiple activity chart can best be shown by an example.
 MOVEMENT OF WORKERS IN THE WORKING AREA

Figure 44. Multiple activity chart: inspection of catalyst in a converter (original method)

HOURS ELECTRICIAN FTTTER PROCESS

AND MATE AND MATE RIGGER MEN

T *;rv
ll'""ln"J'*
EXAMPLE OF A MULTIPLE ACTIVITY CHART APPLIED TO TEAM WORK:
INSPECTION OF CATALYST tN A CONVERTERl
tr RECORD
This is an application in the field of plant maintenance and is useful in show-
ing that method study is not confined to repetition or production operations.
During the "running-in" period of a new catalytic converter in an organic
chemical plant, it was necessary to make frequent checks on the condition of the
catalyst. In order that the converter should not be out of service for any longer than
was strictly necessary during these inspections, the job was studied.
In the original method the removal of the top of the vessel was not started
until the heaters had been removed, and the replacement of the heaters was not started

tAdapted lrom an example in Method study, a handbook issued by Imperial Chemical Industries
Ltd. Work Study Department. 137
 unril the top had been completely fixed. The original operation, with the relationships
between the working times of the various workers, is shown in figure 44.

U EXAMINE critically
It will be seen from this chart that, before the top of the vessel was removed
by the fitter and his mate, the heaters had to be removed by the electrician and his
mate. This meant that the fitters had to wait until the electricians had completed their
work. Similarly, at the end of the operation the heaters were not replaced until the top
had been replaced, and the electricians had to wait in their turn. A critical examination
of the operation and questioning of the existing procedure revealed that in fact it was
not necessary to wait for the heaters to be removed before removing the top.

Figure 45. Multiple activity chart: inspection of catalyst in a converter (improved method)

ELECTRICIAN FITTER PROCESS

HOURS AND MATE AND MATE RIGGER MEN

TIME
SAVED
32 PER CENT

138
I
tr DEVELOP the new method
Once this had been determined, it was possible to arrange for the top to be
unfastened while the heaters were being removed and for the heaters to be replaced
while the top was being secured in place. The result appears on the chart in figure 45.
It will be seen that the idle time of the electrician and fitter and their respec-
tive mates has been substantially reduced, although that of the rigger remains the
same. Obviously the rigger and the process men will be otherwise occupied before and
after performing their sections of the job and are not, in fact, idle while the heaters and
cover are being removed or replaced. The saving effected by this simple change was
32 per cent of the total time of the operation.
The simple form of multiple activity chart shown here can be constructed
on any piece of paper having lines or squares which can be used to form a time scale.
lt is more usual, however, to use printed or duplicated forms, similar in general layout
to the standard flow process charts, and to draw vertical bars to represent the ac-
tivities charted. Figures 46,47 and 50 show multiple activity charts drawn on printed
forms.
The multiple activity chart can also be used to present a picture of the
operations performed simultaneously by a man and one or more machines. The chart
may be drawn in the manner shown in figure 46, with the vertical activity bars close to
each other down the middle of the sheet. In this way the beginning and end, and hence
the duration, of every period of activity of either man or machine are clearly seen in
relation to one another. By a study of these activities it is possible to determine
whether better use can be made of the operative's time or of the machine time. [n par-
ticular, it offers a means of determining whether a man minding a machine, whose
time is only partly occupied, can manage to service another machine, or whether the
increase in ineffective time of the two machines will offset any gain to be obtained
from employing the man's time more fully. This is an important question in those
countries where manpower is more readily available than machines and other capital
equipment.

EXAMPLE OF A MULTIPLE ACTIVITY CHART RECORDING MAN AND

MACHINE: FINISH MILL CASTING ON A VERTICAL MILLER

tr RECORD
Figure 46 represents a common form of man-and-machine multiple activity
chart recording the operation of a vertical milling machine finish-milling one face of a
cast iron casting parallel to the opposite face, which is used for locating it in the fix-
ture. This is a very simple example, typical of the sort of operation carried out every
day in an engineering shop.
The heading of the chart records the usual standard information, with one
or two additions. The graduated scale on the edge of the chart can be made to repre-
sent any scale of time required; in this case one large division equals 0.2 of a minute.
The making of the chart and noting of the operations are self-evident and should not
require further explanation. 139
 MOVEMENT OF WORKERS IN THE WORKING AREA

Figure 46. Multiple activity chart-man and machine: finish mill casting briginal method)

MULTIPLE ACTIVITY CHART

CHABT No.A SHEET No. I OF I S U M M A R

PRODUCT: PRESENT PROPOSED SAVING

CYCLE TIME (min)
8,239 Castins
DRAWING No. B.239ll Man 20
Machine 2.O
PROCESS:
Finish mill sacond faca WORKING
Man 1.2
Machine o-a
MACHINE(S): SPEED FEED IDLE
Cincinnati No.4 80 15 Man o.a
vartical millq r,p.m. in.lmin Machine 1.2
UTILISATION
OPERATIVE: CLOCK No. 1234 Man 60%
CHARTED BY: DATE: Machino /rlr%

TIME MAN MACHINE

TIME

I
(min) (min)

Removes finishad casting

Cleans with compressod ait o.2

Gaugas dopth on suiace plate

o.4 o.4

Breaks sharp edga with file ldlo

0.6 Claans with comprassed air o.6

Places in box
o.B Obtains naw casting 08

Cleans machina with comprcssed ait

t.o !.0
Locatas casting in fixlure:
1.2 stans machina and auto feed t.2

1.tt t.4

ldla Wo*ing
t.6
Finish mill socond lace r.6

r.8 t.8

20 ?.0

2.2

2.1 2.4

7.6 2.6

2,E 2.8

3.0 3.0

32 t.2

3.4 3-t

- 3.6 3.6

3.8 3.8

140
 MOVEMENT OF WORKERS IN THE WORKING AREA

Figure 47. Multiple activity sfian-m6n and machine: finish mill casting (improved method)

MULTIPLE ACTIVIW CHART

CHART No.9 SHEET No. I oF t s U M M A R

PBODUCT PRESENT PROPOSED SAVING

I 239 Castins CYCLE TIME {min)
DRAWING No.8.239/l Man 2.O 1-36 o.64
Machins 2.0 t.36 o.64
PROCESS
Finish mill second faco WORKING
Man 1.2 1.12 o.o8
Machine o.8 o.8
MACHINE(S) SPEED FEED IDLE
Cincinnoti No.4 vonical millil 80 ,5 o.a u.24 o.56
Lp.m. in.lmin Machine 1.2 o.56 o.64
UTILISATION Gain
OPERATIVE: CLOCK No. 1234 Man 60* ur% 2fi
CHARTED BY: DATE; Machine /tth 5lX tlx
TIME TIME
MAN MACHINE min
mln
Ramovas linished casting
o.2 o.2

Claans machine with cotpprossod air. Locates now

ldla
o.4 casting in lixtuto: starts machina and outo faed o.4

o.8 o.6

Brcaks edga ol machinad casting with tile:

cleans with comprossed air
o.B 0.8

Gaugas depth on suiaco plato

t.o Places casting in box: Picks ltp now casting Working t.0
^nd
Finish mill sacond lace

I
t-2 1.2

ldlo
1.L 1.L

t6 t.6

ia t8

2.0 2.0

2.2 2.2

2.a 2,1

2.6 ?.6

,i 2.6 -
3_O 3.0

3-2 37

3.4 3.t

3.6 3.6

3.t 3.0

141
 MOVEMENT OF WOBKERS IN THE WORKING AREA

tr EXAMINE critically
It will be seen from flrgure 46, which represents the method by which the
operative was doing the job before the study was made, that the machine remains idle
during nearly three-quarters of the operation cycle. This is due to the fact that the
operative is carrying out all his activities with the machine stopped, but remains idle
while the machine is running on an automatic feed.
Examination of the chart shows that the work carried out by the operative
can be divided into two parts: that which must be done with the machine stopped,
such as removing and locating the workpiece, and that which can be done while the
machine is running, such as gauging. It is obviously an advantage to do as much as
possible while the machine is running as this will reduce the over-all operation cycle
time.

! DEVELOP the new method

Figure 47 shows the improved method of operation. It will be seen that
gauging, deburring the edges of the machined face, placing the casting in the box of
finished work, picking up an unmachined casting and placing it on a work table ready
to locate in the fixture are now all done while the machine is running. A slight gain in
time has been made by placing the boxes with the finished work and the work to be
done next to one another, so that one casting can be put away at the same time as the
new one is lifted from its box. The cleaning of the machined casting with compressed
air has been deferred until after the sharp edges have been broken down, thus saving
an extra operation.
The result of this rearrangement, which has involved no capital outlay, is a
saving of 0.64 of a minute on 2 minutes, a gain of 32 per cent in the productivity of
the milling machine and operative.
The next example is one of a multiple activity chart recording the activities
of a team of workers and a machine.

EXAMPLE OF MULTIPLE ACTIVITY CHART RECORDING THE

ACTIVITIES OF A TEAM OF WORKERS AND A MACHINE:
FEEDING BONES TO A CRUSHER IN A GLUE FACTORY

This interesting example of a combined teamwork and machine chart (see

figure 48) is applied to the feeding of sorted bones from a storage dump to a crushing
machine in a glue factory in a developing country.
The original layout of the working area is shown in figure 49. Raw material
in the form of animal bones of all sorts was brought by the suppliers to one of the
dumps labelled "Bones", 80 metres from the bone crusher. The crusher was fed by
means of a small trolley running on rails.

t] RECORD
o'hard" types. The selected bones
workers sorted the bones into'osoft" and
were carried to a heap, ready for loading by two workers into the trolley. The loading
142 was done by hand. These two workers were idle during the time that the trolley was
 MOVEMENT OF WORKERS IN THE WORKING ABEA

Figure 48. Combined team work and machine multiple activity chart: crushing bones
(original method)

MU LTIPLE ACTIVITY CHART

CHART No. rO SHEET No.1 OF I (1) MACHINE(S) "/o U1, LISATION
(2) LABOUB: 6AIN
flR€,EUCT/ MATER IAL
Mixed bones (1 ) Crusher 68
Trolley 96
OPERATION: Load and tnnsport bones in uolley
(25O kg load) from dump to crusher (2) Loaders 2 47.5 I
frolleymen 2 475 I
METHOD: PRESENT/PROPOSED Crushetmen 4 dEd
LoCATION
CHARTED BY: DATE

Il,T.t :RUSHEB rRoLLEy TRILLEIMEN LIADERI ]l,Yt

l.o f.o
T,,, 7.O /.u

te r4.0
0 ,0 r0

?0 10.0 ro 70.
14.O

t,25 0 0
30

9.5 .0 /.0
14.0

to 4.0

10 25 r.0 ,0
s |t.o

3.75

6
975 0 r0
4.0

0
m ,.0 ,0

i0

Replace 140
n btoken bell --a' 10.0

50

'dle. nol empiled + 5 5

90

6.5 T

14.0
t6
!0 70
L 7.O

llo tn

I
10.0 r.0

t
4.0

T I
L

= lt7sin usis-- LJ
-1m

143
 MOVEMENT OF WOFKERS IN THE WORKING AREA

Figure 49. Crushing bones: layout of working area

BONES

I
I

v*) +-t
+-t
6 +'r
?+'r
[ +.] I
+.1
E
6 I
o
I

I
HE^P OF SETECTED
BONES E
o
@

E I
ct
<! I
I
ao
I u I
z
o I

t,
ao
I L
o I
lt 3
tt
II
I
I
o
J I
I
I
I

r
_r-
I
I
144
 TKERS IN THE WOBKING AREA

being pushed to the crusher, emptied into it and brought back. Two other workers
pushed the trolley; they were idle while it was being loaded.

The following figures relate to the activities of the loaders, the trolley and
the crushing machine during eight cycles, which lasted 117.5 minutes.
Trolley loading time 7 min (2 men)
Trolley to crusher, empty and return 7 min (2 men)
Trolley load 250 kg
Weight transported in 117.5 minutes 8x250:2,000 kg
Crusher waiting time 37.75 min

A chart (figure 48) has been made relating the activities of the crusher, trol-
ley, trolleymen and loaders. From this it will be seen that 10 minutes of the crusher
waiting time was taken up in replacing a broken belt; however, after the belt was
repaired, the crusher ran continuously for 16.5 minutes instead of the usual 10,
because a fresh trolley load was ready for it. If a normal 4 minutes of idleness is
allowed, the net idleness due to the broken belt becomes only 6 minutes.

U EXAMINE critically
A critical examination of the chart shows at once that the crusher was nor-
mally idle for 31.75 out of 111.5 minutes (37.75 out of 117.5 minutes if the 6 minutes
breakdown time is included), or 28.5 per cent of the possible working time. Each of
the two groups of men (loaders and trolleymen) was idle for 50 per cent of its available
time. The first question that might arise in the mind of someone studying the diagram
and chart is: ooWhy cannot the trolleymen load the trolley?"
The answer to this question is that, if they did so, they would get no rest
and would have to work continuously just to keep the crusher going for the same
percentage of its time as at present. There would be a saving of manpower but no
improvement in the productivity of the plant. In any case, no one can work for three
or four hours on end without some rest, especially when engaged on heavy work like
loading and pushing the trolley, where the allowance would normally be 25 per cent or
possibly more of the total time allowed for the job (for the treatment of relaxation
allowances see Chapter 18). If the two trolleymen took their relaxation allowances,
the productivity of the crusher would be still lower.
A study of the diagram of the working area and of the information given
above shows that the workers sorting the bones at the dumps labelled o'Bones" have to
carry the sorted bones from the points where they are working to the ooHeap of
selected bones", so that they can be loaded into the trolley. This raises the question:
"Why cannot the bone sorters load the sorted bones straight into the trolley?"
The answer is that they could do so, if the rails were extended another 20
metres to the bone dumps.
This eliminates the loaders but still leaves the problem of the 4 minutes of
idle time of the crusher, while he is waiting for the trolley to return with a load. There
are more bone sorters than loaders and they can load the trolley more quickly; if
each trolley load were reduced, it would take less time to load and would require less
effort to push. In this way it might be possible to keep up with the cycle of the crusher.
The load was therefore reduced to 175 kilograms. waiting time was eliminated. 145
 MOVEMENT OF WORKERS IN T

tl DEVELOP the improved method

The line of crosses in figure 49 shows the extension of the rails to the bone
dumps. The loaders who were eliminated were transferred to other work in the
factory. This was probably made possible by the fact that, as will be seen, the crusher
output rose substantially as a result of the change of method.
Figure 50 is the multiple activity chart showing the improved method. It will
be seen from this that the percentage running time of the crusher has considerably
improved.

Performance figures are now-

Trolley loading time I min
Trolley to crusher, empty and return 6 min
Trolley load 175 kg
Weight transported in 115.5 minutes 15 x 175:2,625k9
Crusher waiting time 6 min

The crusher waiting time will be seen from the chart to include 3 minutes for
clearing hard bones-an abnormal occurrence. If this time is excluded to enable the
original and improved performances to be compared, the over-all time during which
the crusher is available for action is 112.5 minutes. The increase in output from the
crusher over almost identical periods is 625 kilograms; the increase in productivity of
the crusher is 29.5 per cent.
Two labourers out of eight have been released for other work; the labour
productivity has therefore increased by

/ 2625 x 8
x loo :
\ zooo, o-rlI
75 per cent.

The space formerly occupied by the 'oHeap of selected bones" is now avail-
able for other uses.
This example is a dramatic illustration of the manner in which the produc-
tivity of land, plant and labour can be increased by method study properly and
systematically applied, at a cost of only 20 metres of light railway track.

5. The travel chart

The string diagram is a very neat and effective way of recording for critical
examination the movement of workers or materials about the shop, especially when
readily understood "before" and'oafter" models are needed to help in presenting the
merits of a proposed change. String diagrams do take rather a long time to construct,
however, and when a great many movements along complex paths are involved the
diagram may end up looking like a forbidding maze of criss-crossing lines. When the
movement patterns are complex, the travel chart is a quicker and more manageable
146 recording technique.
 MOVEMENT OF WORKERS IN THE WORKING AREA

Figure 50. Combined team work and machine multiple activity chart: crushing bones
(improved method)

M ULTI PLE ACTIVITY CHAR"I

CHART No. r, SHEET No. t OF t (1) M^cHrNE(s): UTILI5ATION
(O LABOUR: GAIN
MATERIAL:
Maed boncs (1) Lrchct 6E YJ Z'
fmllet 96 95 _,
OPERATION: Lood ond ,rcnsFn Dp/B/,lrollel
(rl5 kg. lold) from dumP lo c6her (2) lmden 2 47.5 Ttnt ittcd
lrclleyma 2 47.5 0l J3.'
METHOD : IlSSEflTi PROPOSED
'Crushuren I
. No' nuiled

CHAPTFD RY. DAIL: N.8. Lodlng w dom b1 bilctt

TIME TIMf
CRUSHER fROLLEY TAOU.ETMEN SORIEA.IOADERS

- l-0
mla
7.0 6.0 mtn Et ltig \.onia rcrt l@ding
\Sorl,ng
o.5 ,.0 Woltlng
a\r@dcr3
10 r0

Rcmovc 3.0
-
hord bones
20

t610
l6d oo,
/ t.0 3.0
I emptted s
r.0

ao
t4.s

!0 0.5 I

Dcloy t.0 ,.0

&

7! ,o

Delol t.0 r.0

o &
lXlol t.0 1.9

I
II
90

o_5

'to
o.5
6.5
i
M.n
fl0 lr0
,t1.0 mtn

lrSS min 7 N. B. During delays to uolley

im sorting continues !20

147
 MOVEMENT OF WORKERS IN THE WORKING AREA

Figure 51 shows a typical travel chart. It records the movements of a mes-

senger delivering papers or information to the various desks and work stations in an
office. The layout of the office, showing the relative positions of the work stations, is
sketched beneath the travel chart.
The travel chart is always a square, having within it smaller squares. Each
small square represents a work station-that is, in the present example, a place visited
by the messenger. There are ten stations, and so the travel chart is drawn with ten
small squares across, numbered I to 10 from left to right, and ten small squares
down, again numbered 1 to l0 going down. Thus for ten work stations the travel chart
contains a total of l0 x 10 : 100 small squares, and has a diagonal line drawn across
it from top left to bottom right.
The squares from left to right along the top ofthe chart represent the places
from where movement or travel takes place: those down the left-hand edge represent
the stations to which the movement is made. For example, consider a movement from
station 2 to station 9. To record this, the studyman enters the travel chart at the
square numbered 2 along the top of the chart, runs his pencil down vertically through
all the squares underneath this one until he reaches the square which is horizontally
opposite the station marked 9 on the left-hand edge. This is the terminal square, and
he will make a mark in that square to indicate one journey from station 2 to station 9.
All journeys are recorded in the same way, always starting at the top in the square of
departure, always travelling vertically downwards, and always ending in the square
opposite the station of arrival, as read from the left-hand edge. Of course, the study
man does not actually trace in the path over which his pencil moves but just places a
small tick or other mark in the terminal square to record the journey.
To make the recording method completely clear, let us suppose that the
messenger travelled the following route: 2 to 9 to 5 to 3 and back to 2. The journey
from 2 to 9 will be marked by a tick as described above. To enter the journey from 9
to 5, the studyman will return to the top of the chart, select square 9, move down the
column below this until he reaches the square opposite 5 on the left-hand edge, and
record the movement by a tick there. To the top again to select square 5, down from
there to that opposite 3; another tick for that journey. Finally, up to the top once more
to select square 3, and down to that opposite number 2 for the recording of the final
leg of the messenger's walk.

EXAMPLE OF TRAVEL CHART: MOVEMENT OF MESSENGER lN AN OFFICE

! RECORD
The flrrst stage of the recording process, that is when the method study man
148 observes the movement of the messenger actually in the office, can be carried out very
 MOVEMENT OF WORKERS IN THE WORKING ABEA

Figure 51. Travel chart: movements of messenger in office

Movement FROM

3456 10

2 @ (D
'@
tr Y
o @
@
7
@
z
.rO
o
r
-o
E
1

2
a / f,
c
3 o a z .9
3

,@ G
4 o o 3 o
o
4
, / 7 F
z
o
t- 5 o o @ o o a 6 q
5
c ,@ ,o C
o
o
E
o
6 a @ @ 5 E
o
6

o ,@ o
7 o @ @ + E
o
7

,@

4
J
8 "@ @ 3 o I
E
7 E
9 @ a 7 =
.t) I

10 @ @ @ @ @ 5 L 10

z .lO 2 5 6 5 ? 3 7 5
SummaV of movements FROM station number
1- 1
1 2 3 4 5 6 7 I I 10

Layout sketch
of office
showing location
of stations

149
 MOVEMENT OF WORKEBS IN THE WORKING AREA

Figure 52. Simple study sheet

STUDY SHEET

Department: nilaaE Section ./ StudyNo. l$7

Equipment: l,;ll iiral, hll,l, Sheet: / of 2
Operation: lltflt*..t;A. on ol.obhl habh, Taken by: CAA

nildrr. ad lLu h iu*rh, UlrN Date:

T.2u z C' 7 + .3 q 6 , q 6 J 2 ?
D .l 7 tl 3 q 6 I .l 6 3 2 q 7
ilo LO to 30 to 30 to so
"$.Ju
7...* 7 I 3 I I I z 5 ? 7 z 5 ?
to , 6 + ? I z 5 q 7 z 5 q e
{o. olau lo 20 30 lo 20 to tto ,lO zo to 30 tt<)

Ttm, 6 ,l ?
T6 ,l .l 6
.r%. J ant, 30 30
-/
-/

simply on a study sheet similar to that shown in figure 52. Once the stations visited
have been numbered and keyed to a sketch of the workplace, the entries recording the
journeys made require very little writing.
The travel chart is then compiled in the method study oflice. After all the
movements have been entered on the chart with ticks, the ticks in each small square
are added up, the total being entered in the square itself. The movements are then
summarised, in two ways. Down the right-hand side of the chart, the number of move-
ments into each station is entered against the square representing the station, as read
from the left-hand edge. Underneath the chart, the number of movements ftom each
station is recorded, this time under the relevant squares as read off the top of the
chart.
In the chart in figure 51 there were two movements into station 1, as can be
seen by running an eye across the line of squares against station 1 on the left-hand
edge. Similarly, in the next horizontal line of squares, that opposite station 2, there are
150 altogether 10 movements shown, into station 2. For the movements from stations, the
 MOVEMENT OF WORKERS IN THE WORKING AREA

totalling is carried out vertically: it will be seen that there were 10 movements into sta-
tion 2, as shown in the column of squares under station 2 at the top of the chart. With
very little practice, the chart and its summaries can be compiled extremely
quickly-much quicker than it takes to describe what is done.
ln figure 51 the summary of movements into each station shows the same
number of movements as those recorded at the bottom as being made from that sta-
tion, indicating that the messenger ended his travels at the same station as he started
out from when the study commenced. If he had finished somewhere else (or if the
stufy had been broken off when he was somewhere else), there would have been one
station where there was one more movement in than the number of movements out,
and this would be where the study hnished.

tr EXAMINE critically
An examination of the chart shows that ten journeys have been made into
station 2, seven into station 9, and six into station 5. These are the busiest stations. A
scrutiny of the body of the chart helps to confirm this: there were six journeys from
station 2 to station 9, and five from station 5 to station Z.The busiest route is 5-2-9.
This suggests that it would be better to locate these stations next to each other. It
might then be possible for the clerk at station 5 to place finished work directly into the
in-tray at station 2, and the clerk there to pass his work on to station 9, thus relieving
the messenger of a good deal of his travelling.

EXAMPLE OF A TRAVEL CHART: MATERIAL HANDLING

An example of a travel chart compiled as part of a material-handling study

is shown in figure 53. In the shop in which the study was made, eight mixing machines
were used to mix materials in different proportions, the final mixtures being taken to
an inspection bench (station 6). The mixes were transported in 25-litre cans, which
were placed on pallets and moved by a low lift truck.

t] RECORD
Movements were recorded on the shop floor on a study sheet of the type
shown in figure 52. The entries show not only the journeys made but also the number
of cans carried on each trip. In the travel chart shown in figure 53, there are nine sta-
tions, the eight mixing machines and the inspection bench. The travel chart was made
exactly as in the previous example, except that in this instance the number of cans
delivered was also entered in the destination squares, beside the ticks for the journeys,
and both journeys and cans delivered have been summarised. It will be seen that, for
instance, two journeys were made from station 5 to station 9, one with a load of 40
cans and the other with 30.

U EXAMINE critically
Not much can be learned from the study sheet, except that seven of the 29
trips made were run without any load, and that the size of load varied from 10 to 40
cans. The travel chart, however, shows at once that stations 6 and 9 are busy ones.
Five trips were made to station 6, with a total of 150 cans being delivered. (Station 6
was the inspection bench.) Four of these trips were from station 9, bringing in a total
of 130 cans. The largest number of trips, and the greatest quantity of cans, was from 't 51
 MOVEMENT OF WORKERS IN THE WORKING AREA

Figure 53. Travel chart: materials

:
E-
Movement FROM Summary
Y No. of No. of
trips INTO cans
Station I 4O\V.,O
5 zo
J act YU
3 {o
o f.& fto
F L LO
o)
E
t?3
@ 2 2A
o
/4
/ro ,K)
Z
rizlt
5 4g
47 /.=
7ro
ru
3 .to

I qo
ft9 (.Q fsa (1+<
I t& ,s( I t70

Summary

No. of
trips 3 t222+ 54 I
o
E
tt

t;;lt 50 to +o to zo so ?e 4@
station 9 to the inspection bench, suggesting that this route might be laid out so that it
would be as short as possible. It might be possible to install a roller conveyor between
these points, thus relieving the lift truck of a great deal of work.
Eight trips were made into station 9, to deliver 170 cans. The cans came
from stations 1,2,4 and 5, one trip without load being made from station 3. Stations
1,2, 4 and 5 appear to feed station 9, which sends its work on to the inspection bench
(longer study might be necessary to confirm this). If so, there would be a case for
modifying the layout of the shop in order to bring these stations closer together, when
roller conveyors might allow gravity to do most of the transporting between them. In
this example there is no sketch of the shop layout or table of distances between sta-
tions, both of which are essential complements to a travel chart.
It is interesting to note that four trips were made from station 2, but only
three into the station; and that only four were made from station 6, although five were
made into it. This is because the study started at station 2 and finished at the inspec-
152 tion bench.
 ChapteUl
Methods and movements
atthe workplace

1. General considerations
In this book we have gradually moved from the wide field of the produc-
tivity of industry as a whole to considering in a general way how the productivity of
men and machines can be improved through the use of work study. Still moving from
the broader to the more detailed approach, we have also examined procedures of a
general nature for improving the effectiveness with which complete sequences of
operations are performed and with which material flows through the working area.
Turning from material to men, we have discussed methods of studying the movements
of men around the working area and the relationships between men and machines or
of men working together in groups. We have done so following the principle that the
broad method of operation must be put right before we attempt improvements in
detail.
The time has now come to look at one man working at a workplace, bench
or table and to apply to him the principles which have been laid down and the
procedures shown in the examples given.

In considering the movements of men and materials on the larger scale, we

have been concerned with the better utilisation of existing plant and machinery (and,
where possible, materials) through the elimination of unnecessary idle time, the more
effective operation of processes and the better utilisation of the services of labour
through the elimination of unnecessary and time-consuming movement within the
working area of.factory, department or yard.
As our example (Chapter 10) of the trolleymen's need for relaxation shows,
the factor of fatigue affects the solution of problems even when we are dealing with
areas larger than the individual workplace. But when we come to study the operative
at the workplace, the way in which he applies his effort and the amount of fatigue
resulting from his manner of working become primary factors affecting his produc-
tivity.
Before embarking on a detailed study of an operative doing a job at a single
workplace, it is important to make certain that the job is in fact necessary and is being
done as it should be done. The questioning technique must be applied as regards-

t] PURPOSE
to ensure that thejob is necessary; 153
 tr PLACE
to ensure that it is being done where it should be done;

tr SEQUENCE
to ensure that it is in its right place in the sequence of operations;

tr PERSON
to ensure that it is being done by the right person.
Once these have been verified and it is certain that the job cannot be
eliminated or combined with another operation, it is possible to go on to determine the

N MEANS
by which the job is being done
and to simplify them as much as is economically justified.
Later in this chapter we shall consider the recording techniques adopted to
set out the detailed movements of an operative at his workplace in ways which
facilitate critical examination and the development of improved methods, in particular
the two-handed process chart. Before doing this, however, it is appropriate to discuss
the principles of motion economy and a number of other matters which influence the
design of the workplace itself, so as to make it as convenient as possible for the worker
to perform his task.

2. The principles of motion economyl

There are a number of "principles" concerning the economy of movements
which have been developed as a result of experience and which form a good basis for
the development of improved methods at the workplace. They were first used by
Frank Gilbreth, the founder of motion study, and have been amplified by other
workers, notably Professor Barnes.2 They may be grouped under three headings-

A. Use of the human body

B. Arrangement of the workplace
C. Design of tools and equipment

They are useful in shop and office alike and, although they cannot always be applied,
they do form a very good basis for improving the efliciency and reducing the fatigue
of manual work. The ideas expounded by Professor Barnes are described here in a
somewhat simplified fashion.
A. Use of the human body
When possible-

t In the B. S. Glossary, op. cit., the term

"characteristics of easy movement" is preferred, rather than
"principles ol motion economy". The eadier term has been retained here, however, as being more descriptive of
the rest ofthis section ofthe chapter.
2
See Ralph M. Barnes: Motion and time study: Design and measurement of work (New York and
154 London, John Wiley, 6th ed., 1969), Chapters 17-19.
 VEMENTS AT THE WORKPLACE

l. The two hands should begin and complete their movements at the same time.
2. The two hands should qot be idle at the same time except during periods of rest.
3. Motions of the arms should be symmetrical and in opposite directions and should
be made simultaneously.
4. Hand and body motions should be made at the lowest classification at which it is
possible to do the work satisfactorily (see section 3 below).
5. Momentum should be employed to help the worker, but should be reduced to a
minimum whenever it has to be overcome by muscular effort.
6. Continuous curved movements are to be preferred to straight-line motions involv-
ing sudden and sharp changes in direction.
7. "Ballistic" (i.e. free-swinging) movements are faster, easier and more accurate than
restricted or controlled movements.
8. Rhythm is essential to the smooth and automatic performance of a repetitive
operation. The work should be arranged to permit easy and natural rhythm
whenever possible.
9. Work should be arranged so that eye movements are confined to a comfortable
area, without the need for frequent changes of focus.

B. Arrangement of the workplace

l. Definite and fixed stations should be provided for all tools and materials to permit
habit formation.
2. Tools and materials should be pre-positioned to reduce searching.
3. Gravity feed, bins and containers should be used to deliver the materials as close to
the point of use as possible.
4. Tools, materials and controls should be located within the maximum working area
(see figure 54) and as near to the worker as possible.

5. Materials and tools should be arranged to permit the best sequence of motions.
6. "Drop deliveries" or ejectors should be used wherever possible, so that the
operative does not have to use his hands to dispose of the finished work.
7. Provision should be made for adequate lighting, and a chair of the type and height
to permit good posture should be provided. The height of the workplace and seat
should be arranged to allow alternate standing and sitting.
8. The colour of the workplace should contrast with that of the work and thus reduce
eye fatigue.

C. Design of tools and equipment

l. The hands should be relieved of all work of "holding" the workpiece where this can
be done by ajig, fixture or foot-operated device.
2. Two or more tools should be combined wherever possible.
3. Where each finger performs some specific movement, as in typewriting, the load
should be distributed in accordance with the inherent capacities of the fingers. 1 55
 METHODS AND MOVEMENTS AT THE WOBKPLACE

Figure 54. Normal and maximum working areas

NORMAL WORKING AREA

Diagram 1. FINGER, WRIST AND ELBOW MOVEMENTS

Diagram 2.
MAXIMUM WORKING AREA
SHOULDER MOVEMENTS

Right hand
maximum
working area

4. Handles such as those on cranks and large screwdrivers should be so designed that
as much of the surface of the hand as possible can come into contact with the
handle. This is especially necessary when considerable force has to be used on the
handle.
5. Levers, crossbars and handwheels should be so placed that the operative can use
them with the least change in body position and the greatest "mechanical advan-
156 tage".
 METHODS AND MOVEMENTS AT THE WORKPLACE

These "principles", which reflect those discussed in Chapter 6, can be made

the basis of a summary'oquestionnaire" which will help, when laying out a workplace,
to ensure that nothing is overlooked.
Figure 54 shows the normal working area and the storage area on the
workbench for the average operative. As far as possible, materials should not be
stored in the area directly in front of him, as stretching forwards involves the use of
the back muscles, thereby causing fatigue. This has been demonstrated by physio-
logical research.

3. Classification of movements
The fourth "rule" of motion economy in the use of the human body calls for
movements to be of the lowest classification possible. This classification is built up on
the pivots around which the body members must move, as shown in table 10.

Table lO. Classification of movements

Pivot Body membe(s) moved

I Knuckle Finger
2 Wrist Hand and lingers
3 Elbow Forearm, hand and fingers
4 Shoulder Upper arm, forearm, hand and fingers
5 Trunk Torso, upper arm, forearm, hand and fingers

is obvious that each movement above Class I will involve movements of

It
all classes below it. Thus the saving in effort resulting from using the lowest class pos-
sible is obvious. If, in laying out the workplace, everything needed is placed within
easy reach, this will minimise the class of movement which the work itself requires
from the operative.

4. Further notes on workplace layout

A few general notes on laying out the workplace may be useful.
l. If similar work is being done by each hand, there should be a separate supply of
materials or parts for each hand.
2. If the eyes are used to select material, as far as possible the material should be kept
in an area where the eyes can locate it without there being any need to turn the
head.
3. The nature and the shape of the material influence its position in the layout.
4. Hand tools should be picked up with the least possible disturbance to the rhythm
and symmetry of movements. As far as possible the operator should be able to pick
up or put down a tool as the hand moves from one part of the work to the next,
without making a special journey. Natural movements are curved, not straight;
tools should be placed on the arc of movements, but clear of the path of movement
of any material which has to be slid along the surface of the bench. 157
 \T THE WORKPLACE

5. Tools should be easy to pick up and replace; as far as possible they should have an
automatic return, or the location of the next piece of material to be moved should
allow the tool to be returned as the hand travels to pick it up.
6. Finished work should be-
(a) dropped down a hole or a chute;
(D) dropped through a chute when the hand is starting the first motion of the next
cycle;
(c) pat in a container placed so that hand movements are kept to a minimum;
(d) if the operation is an intermediate one, placed in a container in such a way that
the next operative can pick it up easily.
7. Always look into the possibility of using pedals or knee-operated levers for locking
or indexing devices on fixtures or devices for disposing of finished work.

AN EXAMPLE OF A WORKPLACE LAYOUT

Let us now look at a typical workplace with the principles of motion
economy and the notes in the previous section in mind.
Figure 55 shows a typical example of the layout of a workplace for the
assembly of small electrical equipment (in this case electric meters). Certain points
will be noticed at once:
(l) A fixture has been provided for holding the workpiece (here the chassis of the
meter), leaving both the operative's hands free for assembly work. The use of one
hand purely for holding the part being worked on should always be avoided, ex-
cept for operations so short that a fixture would not be justified.
(2) The power screwdriver and box spanner are suspended in front of the operative so
that she has to make only a very short and easy movement to grasp them and
bring them to the work. They are, however, clear of the surface of the table and of
the work. The hammer and hand screwdriver for use with the left hand are within
easy reach, so that the operative can pick them up without searching, although
picking up the screwdriver might involve a little fumbling. They are in line with
the trays of parts but below them, and so do not get in the way.
(3) All the small parts are close to the operative, well within the o'maximum working
are{'. Each part has a definite location, and the trays are designed with "scoop"
fronts for easy withdrawal, parts being drawn forward with the tips of the fingers
and grasped as they come over the rounded edge. They are arranged for sym-
metrical movements of the arms, so that parts which are assembled simultane-
ously are picked up from trays in the same relative position to the operative, on
either side of her. It will be noted that the trays come almost in front of the
operative, but this is not very important in this case as the length of reach is not
excessive and will not involve much play of the shoulder and back muscles.
(4) The operative has taken a small number of the formed wire parts normally kept in
a tray to her left front and placed them conveniently in front of and to the side of
the workpiece, in order to make a shorter reach.
(5) The backrest of the operative's chair is an interesting and ingenious improvisa-
158 tion. Special chairs with this type of backrest were not produced locally.
 METHODS AND MOVEIVENTS AT THE WORKPLACE

Assembling an electric meter

* t{n,

8,

5. Notes on the design of jigs, tools and fixtures

The designer's object in providing jigs and fixtures is primarily accuracy in

machining or assembly. Often, opening and closing them or posilioning ihe *orkpiece
calls for more movements on the part of the operative than are stricfly1"".rru.y. Fo. 159
 METHODS AND MOVEMENTS AT THE WORKPLACE

example, a spanner may have to be used to tighten a nut when a wing nut would be
more suitable; or the top of the jig may have to be lifted off when the part might be
slid in.
Co-operation between the work study man and the jig and tool designers, in
industries where they are employed (principally the engineering industry), should start
in the early stages of designing, and tool designers should be among the first people to
take appreciation courses in method study. Some points worth noting are-

(1) Clamps should be as simple to operate as possible and should not have to be
screwed unless this is essential for accuracy of positioning. If two clamps are re-
quired, they should be designed for use by the right and left hands at the same
time.
(2) The jig should be such that both hands can load parts into it with a
design of the
minimum. of obstruction. There should be no obstruction between the point of
entry and the point from which the material is obtained.
(3) The action of unclamping a jig should at the same time eject the part, so that ad-
ditional movements are not required to take the part out of the jig.
(4) Where possible on small assembly work, fxtures for a part which does not require
both hands to work on it at once should be made to take two parts, with suffrcient
space between them to allow both hands to work easily.
(5) In some jigs are made to take several small parts. It will save loading time if
cases
several parts can be clamped in position as quickly as one.
(6) The work study man should not ignore machine jigs and fixtures such as milling
jigs. A great deal of time and power is often wasted on milling machines owing to
the fact that parts are milled one at a time, when it may be quite feasible to mill
two or more at once.
(7) If spring-loaded disappearing pins are used to position components, attention
sfroutd be paid to theit strength of construction. Unless the design is robust, such
devices tend to function well for a while but then have to be repaired or
redesigned.
(8) tn introducing a component into a jig it is important to ensure that the operative
should be able to see what he is doing at all stages; this should be checked before
any design is accepted.

6. Machine controls and displays of dials

Until recenfly, machinery and plant of all kinds was designed with very little
thought being given to the convenience of the operative. In short cycle work especial-
ly, tlie manipuLtion of the controls (changing speeds on a capstan lathe, for example)
often involvis awkward movements. There is not much that the user can do about the
controls of a machine after he has bought iU but he can draw the attention of the
makers to inconvenient controls so that they can make improvements in later models'
There is some evidence that machinery makers generally are beginning to be more
160 conscious of this problem, but a great deal remains to be done. In the few companies
 METHODS AND MOVEMENTS AT THE WORKPLACE

that make their own machinery or plant, the work study department should be called
in at the earliest possible stage ofthe design process, to give assistance and advice.
Physiologists and psychologists have given some thought to the arrange-
ment of dials with a view to minimising the fatigue to people who have to watch them.
The arrangement of the control panels for chemical processes and similar types of
process is often made at the works installing them, and the work study man should be
consulted when this is done.
There is a good deal of published literature on the subject, and this can be
consulted in order to arrive at an easily readable o'display" or arrangement of dials or
visual indicators.
The growing awareness of the importance of arranging machine controls
and workplaces so that they are convenient for the people who have to do the work
has led in recent years to the development of a new field of scientific study which is
concerned entirely with such matters. This is ergonomics:l the study of the
relationship between a worker and the environment in which he works, particularly
the application of anatomical, physiological and psychological knowledge to the
problems arising therefrom. Ergonomists have carried out many experiments to
decide on matters such as the best layout for machine controls, the best dimensions
for seats and worktops, the most convenient pedal pressures, and so on. It may be ex-
pected that their findings will gradually be incorporated in the designs of new
machines and equipment over the next few years, and will eventually form the basis of
standard practice.

7. The two-handed process chart

The study of the work of an operative at the bench starts, as does method
study over the wider field, with a process cha'rt. In this case the chart used is the fifth
of the charts indicating process sequence (table 9), the one known as the two-handed
process chart.

The two-handed process chart is a specialised form of process chart

because it shows the two hands (and sometimes the feet) of the operative moving or
static in relation to one another, usually in relation to a time scale. One advantage of
incorporating a time scale in the chart form is that the symbols for what the two hands
are doing at any given moment are brought opposite each other.

t See Chapter 6.
161
 METHODS AND MOVEMENTS A

The two-handed process chart is generally used for repetitive operations,

when one complete cycle of the work is to be recorded. Recording is carried out in
more detail than is normal on flow process charts. What may be shown as a single
operation on a flow process chart may be broken down into a number of elemental ac-
tivities which together make up the operation. The two-handed process chart generally
employs the same symbols as the other process charts; however, because of the
greater detail covered, the symbols are accorded slightly different meanings-

o OPERATION is used for the activities of grasp, position, use, release, etc.
of a tool, component or material.

D TRANSPORI is used to represent the movement of the hand (or limb) to

DELAY
or from the work, or a tool, or material.
is used to denote time during which the hand or limb being
D charted is idle (although the others may be in use).

V HOLD
(oostorage")
The term storage is not used in connection with the two-
handed process chart. Instead, the symbol is redesignated as
hold and is used to represent the activity of holding the
work, a tool or material-that is, when the hand being
charted is holding something.
The symbol for inspection is not much used because the hand movements
when an operative is inspecting an article (holding it and examining it visually or
gauging it) may be calssified as "operations" on the two-handed chart. It may, how-
ooinspection"
ever, sometimes be useful to employ the symbol to draw attention to the
examination of a piece.r
The very act of making the chart enables the work study man to gain an in-
timate knowledge of the details of the job, and the chart itself enables him to study
each element of the job by itself and in relation to other elements. From this study
ideas for improvements are developed. These ideas should be written down in chart
form when they occur, just as in all other process charting. It may be that different
ways of simplifying the work can be found; if they are all charted, they can be com-
pared easily. The best method is generally that which requires the fewest movements.
The two-handed process chart can be applied to a great variety of assembly,
machining and clerical jobs. In assembly operations, tight fits and awkward position-
ing present certain problems. In the assembly of small parts with close fits, "position-
ing before assembly" may be the longest element in the cycle. In such cases "posi-
tioning" should be shown as a separate movement ('Operation") apart from the
actual movement of assembly (e.g. fitting a screwdriver in the head of a small screw).
Attention can thus be focused on it and, if it is shown against a time scale, its relative
importance can be assessed. Major savings can be made if the number of such
positionings can be reduced, as for example by slightly countersinking the mouth of a
hole and putting a chamfer on the end of the shaft fitting in it, or by using a screw-
driver with a self-centring bit.
, Some authorities feel that the standard process-chart symbols are not entirely suitable for recording
hand and body movements and have adopted variants, such as-
O: Operation. H: Hold.
Loaded. R:
TL: Transport Rest.
162 TE: Transport Empty.
 METHODS AND MOVEMENTS AT THE WORKPLACE

NOTES ON COMPILING TWO-HANDED PROCESS CHARTS

The chart form should include-
Spaces at the top for the usual information.
Adequate space for a sketch of the layout of the workplace (corresponding
to the flow diagram used in association with the flow process chart), or
sketch ofjigs, etc.
Spaces for the movements of right and left hands.
Space for a summary of movements and analysis of idle time.
Examples are given in the following pages.
Some points on compiling charts are worth mentioning-
l. Study the operation cycle a few times before starting to record.
2. Chart one hand at a time.
3. Do not record more than a few symbols at a time.
4. The action of picking up or grasping a fresh part at the beginning of a cycle of
work is a good point at which to start the record. Start with the hand that handles
the part first or the hand that does the most work. The exact point of starting is not
really important, as the complete cycle will eventually come round to it again, but
the point chosen must be definite. Add in the second column the kinds of work
done by the other hand.
5. Only record actions on the same level when they occur at the same moment.
6. Actions which occur in sequence must be recorded on the chart at different
horizontal levels. Check the chart for the time relation of the hands.
7. Care must be taken to list everything the operative does and to avoid combining
operations and transports or positionings, unless they actually occur at the same
time.

EXAMPLE OF A TWO-HANDED PROCESS CHART: CUTTING GLASS TUBES

This very simple example describes how a two-handed process chart was
constructed for cutting off short lengths of glass tube with the aid of a jig. This is
illustrated on the form; the operations involved are self-explanatory (figure 56).

tr RECORD
In the original method the tube was pressed to the stop at the end of the jig,
marked with the file and then eased back for notching. It was then taken out of the jig
for breaking. The chart goes into great detail in recording the movements of the
hands, because in short cycle work of this kind fractions of seconds, when added
together, may represent a large proportion of the total time needed for the job.

D EXAMINE critically
An examination of the details of the original method, using the questioning
technique, at once raises certain points. (It is not considered necessary to go through 163
 METHOOS AND MOVEMENTS AT THE WOBKPLACE

Figure 56. Two-handed process chart: cutting glass tubes (original method)

TWO.HANDED PROCESS CHART

CHART No. / SHEET No.1 OF I WORKPLACE LAYOUT

DRAWING AND PART: Glasstube 3 mm dia.,

ORIGINAL METHOD
I metre orisinal length
OPERATION: Cut to lengths of 1.5 cm

+._.ltG
LOCATION: General shoP
OPERATIVE:
CHARTED BY: DATE:

LEFT.HAND DESCRIPTION olo D V oto D V RIGHT.HAN D DESCRIPTION

Holds tube Picks up file

To iio Holds file
lnserts tube to iis File to tube
Presses to end Holds file
Holds tube Notches tube with file
Withdrcws tube slishtlv Holds file
Rotates tube l20"/180" Holds file
Pushes to end iis Moves file to tube
Holds tube Notches tube
Withdraws tube Places file on table
Moves tube to R.H. Moves to tube
Bends tube to break Bends tube
Holds tube Releases cut Piece
Chanoes oraso on tube To file

SUMMARY
METHOD --W J PROPOSED
L. H. R. H. L.H. I R.H.
Operations 8 5
fransports 2 5
Delays
Holds 4 4
lnspections
Totals 14 14

164
 METHODS AND MOVEMENTS AT THE WORKPLACE

the questions in sequence at this stage in the book: it is assumed that the reader will
always do so.)

l. Why is it necessary to hold the tube in the jig?

2. Why cannot the tube be notched while it is being rotated instead of the right hand
having to wait?
3. Why does the tube have to be taken out of the jig to break it?
4. Why pick up and put down the file at the end of each cycle? Can it not be held?
A study of the sketch will make the answers to the first three questions plain.
l. The tube will always have to be held because the length supported by the jig is
short compared with the total length of the tube.
2. There is no reason why the tube cannot be rotated and notched at the same time.
3. The tube has to be taken out of the jig to be broken because, if the tube were
broken by bending against the face of the jig, the short end would then have to be
picked out-an awkward operation if very little were sticking out. If a jig were so
designed that the short end would fall out when broken, it would not then be neces-
sary to withdraw the tube.

The answer to the fourth question is also obvious.

4. Both hands are needed to break the tube using the old method. This might not be
necessary ifa newjig could be devised.
tl DEVELOP the new method
Once these questions have been asked and answered, it is fairly easy to find
a satisfactory solution to the problem. Figure 57 shows one possible solution. It will
be seen that, in redesigning the jig, the studyman has arranged it in such a way that
the notch is cut on the right-hand side ofthe supporting pieces, so that the short end
will break away when given a sharp tap and it will no longer be necessary to withdraw
the tube and use both hands to break off the end. The number of operations and
movements has been reduced from 28 to six, as a result of which an increase in
productivity of 133 per cent was expected. In fact this was exceeded, because thejob
is now more satisfactory following the elimination of irritating work such as "position
tube in jig". The new method can be carried out without looking closely at the work,
so that workers can be trained more easily and become less fatigued.

8. Reorganisation of a workplace by means of a

two-handed process chart
ASSEMBLY OF POWER MOTOR STARTING WINDING TO COREI
Figure 58 shows the workplace before reorganisation. Some thought has
evidently been given to the operation, since a fxture has been provided for holding the
rThis example from industrial practice was provided by the General Electric Company Ltd, Witton
(United Kingdom), through whose courtesy the photographs and process charts have been made available. The
process charts are reproduced in their original form. It will be seen that they differ somewhat from the newer
practice recommended in this book, but careful examination will make them perfectly clear to the reader. 165
 METHODS AND MOVEMENTS AT THE WORKPLACE

Figure 57. Two-handed process chart: cutting glass tubes (improved method)

TWO-HANDED PROCESS CHART

CHART No.2 SHEET No. / OF 1 WORKPLACE LAYOUT

DRAWING AND PART: Glass tube 3 mm dia. IMPf,OVED METHOD
metre orioinal lenoth
1
OPEMTION: Cut to lenoths of 1.5 cm

<_sToP
LOCATION: General shop
OPERATIVE: POSITTON
CHARTED BY: DATE:
GLASS TUBE
\ FOR NOTCH
,rG

LEFT-HAND DESCRIPTION olo D V olo D V RIGHT.HAND DESCRI PTION

Pushes tube to stop Holds file
Rotates tube Notches with file
Holds tube a Taos with lile:
end drops to box

SUMMARY
PRESENT PROPOSED
METHOD H. t(. H. L.H t-(. H
Operctions I 5 2 2
ftanspotts 2 5
Delays
Holds 4 4
lnsDections
fohls 14 14 3 3

't66
assembly. Apart from this, the organisation of the workplace appears to have been left
to the worker. The various tools and the ring gauge are placed quite conveniently at
ooBefore" process
her right hand, although a study of the chart shows that she always
has to pick up the tamping tools with her right hand and pass them to her left. This
occurs seven times in the course of one assembly. The handles of the tools are
awkward to grasp since they lie flat on the bench. Lengths of systoflex tubing are
upright in a tin in front of the fixture (a long reach for the worker). The prepared coils
(not visible in this figure but seen in a tray in figure 59) are stated in the process chart
to be placed on the shelf in front of the worker (another long reach).
Figure 61 shows the two-handed process charts before and after the altera-
tion in method and re-laying out the workplace, in the original form in which they
were drawn at the time. The process charts are accompanied (figure 60) by right- and
left-handed activity charts (not described in this book) which show the relative activity
of the individual hands. From these it will be seen that under the original method the
left hand is idle during a considerable part of the cycle: the right hand performs nearly
ooBefore" process
twice as many operations. Reference to the chart shows that the left
hand is used very largely either to hold components or to assist the right hand.
The "After" activity chart shows that the activities of the two hands are
more nearly balanced. The number of operations performed by the right hand has
been reduced to 143, although the number of delays has increased from nine to 16.
This, however, is more than compensated by the r.eduction in both the number and the
duration ofthe delays ofthe left hand, whose operations have been reduced to l29.It
will be seen also in figure 60 that transport by hand (H) has been eliminated by the use
of a conveyor (C).
The "After" process chart shows that the left hand is now much more
usefully employed. There is only one "hold" for each hand; although the left hand is
still used to some extent to assist the right, it is also used to carry out a number of
operations of its own.
The process chart, although it gives details of the change in method, does
not give any indication of the changes in the workplace layout. These may be seen in
figure 59.
The workplace has been laid out according to the principles of motion
economy and the working areas shown in figure 54. The workpiece and all the compo-
nents and tools are well within the maximum working area. The fxture is the same,
but it has been placed nearer the edge of the bench, where it is more convenient to the
worker. The systoflex, wedges and other components are conveniently located in stan-
dard trays; the coils (a larger item) are in the large tray within easy reach of the
worker's left hand. Special note should be taken of the positioning of the tools. These
are located for the use of the appropriate hand with the handles in a position that is
easy to grasp: even the scissors are tucked between the trays with their handles
upwards. The ring gauge, which in figure 58 is to be seen lying flat on the bench (a
difficult position from which to pick it up), is now upright in a specially shaped tin on
the right-hand side of the bench where it is very simple to grasp: the operative need
not look up from her work.
Figure 59 repays careful study. The compactness of the workplace en-
courages the operative to keep things in their proper places: a large amount of bench 167
 I\4ETHODS AND MOVEMENTS AT THE WORKPLACE

Figure 58. Example of workplace layout (original method)

Jff
4

%ffi
I d

168
 METHODS AND MOVEMENTS AT THE WORKPLACE

Figure 59. Example of workplace layout (improved method)

"\
5*
,e

169
 METHODS AND MOVEMENTS AT THE WORKPLACE

Figure 6O. Right- and left-handed activity charts: assembly of

power motor starting winding to core

170
 METHODS AND MOVEMENTS AT THE WORKPLACE

space is an invitation to scatter tools and components on it. As regards economy of

lactory space, this new layout will pay for itself in two ways: first by making it pos-
sible to establish more workplaces in a given area; and second, by providing greater
output from a given workplace. The operative will also find the work much less tiring
because she no longer has to stretch and search.

9. Micromotion study
In certain types of operation, and particularly those with very short cycles
which are repeated thousands of times (such as the packing of sweets into boxes or
food cans into cartons), it is worth while going into much greater detail to determine
Table ll. Therbligs

Symbol Name Abbreviation Colour

O Search Sh Black

o Find F Grey

Select SI Light Grey

-)n Grasp G Red

A Hold H Gold ochre

Transport
\O/ Load
TL Green

? Position P Blue

# Assemblc A Violet

U Use U Purple

TT Disassemble DA Light violet

0 Inspect Burnt ochre

Pre-position
E PP Pale blue

,,,O\ Release load RL Carmine red

Transport TE Olive green

Empty

t Rest for over-

coming fatigue
R Orange

a Unavoidable
delay
Avoidable
UD Yellow

AD Lemon yellow
L-O delay

Plan
? Pn Brown
171
 METHODS AND MOVEMENTS A

where movements and effort can be saved and to develop the best possible pattern of
movement, thus enabling the operative to perform the operation repeatedly with a
minimum of effort and fatigue. The techniques used for this purpose frequently make
use of filming, and are known collectively as micromotion study.
The micromotion group of techniques is based on the idea of dividing
human activity into divisions of movements or groups of movements (known as
therbligs) according to the purpose for which they are made.
The divisions were devised by Frank B. Gilbreth, the founder of motion
study; the word "therblig" is an anagram of his name. Gilbreth differentiated l7 fun-
damental hand or hand and eye motions, to which an eighteenth has subsequently
been added. The therbligs cover movements or reasons for the absence of movement.
Each therblig has a specific colour, symbol and letter for recording purposes. These
are shown in table 11.
Therbligs refer primarily to motions of the human body at the workplace
and to the mental activities associated with them. They permit a much more precise
and detailed description of the work than any other method so far described in this
book. On the other hand, considerable practice is required before they can be used for
analysis with any degree of assurance.
It is not felt necessary in an introductory book of this kind to go deeply into
these techniques, because so much can be done to improve productivity by using the
simpler ones already described, before it becomes necessary to use such refinements.
They are used much less than the simpler techniques, even in the highly industrialised
countries, and then mainly in connection with mass-production operations, and they
are more preached about than practised. They are, however, techniques for the expert,
and in any case it would be imprudent for the trainee or comparatively inexperienced
work study man to waste his time trying to save split seconds when there are sure to
be plenty of jobs where productivity can be doubled and even trebled by using the
more general methods.

10. The simo chart

Only one recording technique of micromotion study will be described here,
namely the simultaneous motion cycle char! known as the simo chart for short.

The simo chart is the micromotion form of the man type flow process chart.
Because simo charts are used primarily for operations of short duration, often per-
172 formed with extreme rapidity, it is generally necessary to compile them from films
 METHODS AND I\4OVEMENTS AT THE WORKPLACE

Figure 62. A simo chart'

SIMO CHART
AWING No. AND NAME: 2l Bo,tle Drcppel FILM No. A-6-cc
Top CHART No. 42
iRATION: Assemble SHEET No. lofl
OP. No. DT 27 A CHARTED BY:
ERATIVL DATE:

iu
-z
(,
J
I
J
LEFT HAND u u
<6
1< DESCRIPTION
6
4
u : TIME IN ro
E
g
RIGHT HAND
Ju
)c, r
F
tr 2000/mrn. F
= I
F
DESCRIPTION

0
Finished pot, to ttoy TL 6
TE
,t- 20 To rubber togs
UD

7o bokerire cops TE 16
20
10 G RuDDer lopr

Bokelile cop G E

12 IL To work oreo
To work oreo TL 4
40

6 P To bokelite
For ossembling H t8
6 U
) 'nll Rubber lops
For R.H. to gtosp top P 2. 60 4 TE To lo| of tubbet
2= :G= Top of rubber
For R.H. lo pull tubbet to| H 14
I U Pull rubber lhrough

\^ \_-___
^

made of the operation which can be stopped at any point or projected in slow motion.
It will be seen from the chart illustrated in figure 62 that the movements are recorded
against time measured in "winks" (1 wink : l/2000 minute). These are recorded by a
"wink counter" placed in such a position that it can be seen rotating during the film-
ing.
Motions are classified for each hand according to the list given in section 3
of this chapter. Some simo charts are drawn up listing the fingers used, wrist, lower
and upper arms. The hatching in the various columns represents the therblig colours
associated with the movements; the letters refer to the therblig symbols.
We shall not discuss the simo chart in any greater depth. The reader is
advised not to try out micromotion study in practice without expert supervision.

tAdapted from Marvin E. Mundel: Motion and time study: Principles and practice (Engtewood
Cliffs, NJ, and Hemel Hempstead, UK, Prentice-Hall,4th ed., 1970). 173
 METHODS AND MOVEMENTS AT THE WORKPLACE

11. The use of films in methods analysis

In methods analysis, films may be used for the following purposes:

l. MEMOMOTION PHOTOGRAPHY (A form of time-lapse photography which

records activity by the use of a cin6 camera adapted to take pictures at longer in-
tervals than normal. The time intervals usually lie between % sec and 4 sec).
A camera is placed with a view over the whole working area to take pictures at
the rate of one or two per second instead of the usual rate of 24 frames a second.
The result is that the activities of 10 or 20 minutes may be compressed into one
minute and a very rapid survey of the general pattern of movements may be ob-
tained, from which the larger movements giving rise to wasted effort can be
detected and steps taken to eliminate them. This method of analysis, which is a re-
cent development, has considerable possibilities and is very economical.

MICROMOTION STUDIES
These have already been touched upon in the preceding section. The advantages
of films over visual methods are that they-
(a) permit greater detailing than eye observation;
(b) provide greater accuracy than pencil, paper and watch techniques;
(c) are more convenient;
(d) provide a positive record;
(e) help in the development of the work study men themselves.
Where short cycle operations are being studied, it is usual to make the film into a
loop so that the same operation can be projected over and over again. It is often
necessary to project frame by frame, or to hold one frame in position for some
time. Special film viewers may be used.
Besides the analysis of methods, films can be very useful for

RETRAINING OF OPERATIVES
Both for this purpose and for analysis it may be necessary to have slow motion
pictures of the process (produced by photographing at high speed); considerable
use can be made of loops for this purpose.

12. Other recording techniques

Here we shall describe very briefly one or two other techniques of recording
and analysis which have so far only been mentioned, and which will not be dealt with
further in this introductory book.
Table 9 in Chapter 8 listed five diagrams indicating movement which are
commonly used in method study. Three of these, the flow diagram, the string diagram
and the travel chart, have already been described, with examples, in earlier chapters.
The other two are the cyclegraph and the chronocyclegraph.
The cyclegraph is a record of a path of movement, usually traced by a con-
174 tinuous source of light on a photograph, preferably stereoscopic. The path of move-
 METHODS AND MOVEMENTS AT THE WORKPLACE

ment of a hand, for instance, f,&y be recorded on a photograph in this way if the
worker is asked to wear a ring carrying a small light which will make the trace on the
photograph. Alternatively, such a light may be attached to a worker's helmet if the
purpose is to obtain a record of the path over which he moves during the performance
of a task.
The chronocyclegraph is a special form of cyclegraph in which the light
source is suitably interrupted so that the path appears as a series ofpear-shaped dots,
the pointed end indicating the direction of movement and the spacing indicating the
speed of movement.
In comparison with the other recording techniques outlined in this book, the
cyclegraph and chronocyclegraph are of limited application, but there are occasions
on which photographic traces of this sort can be useful.

13. The development of improved methods

In each of the examples of the different method study techniques given so
far, our discussion has covered the three stages of RECORD, EXAMINE and
DEVELOP, but has been focused primarily on the first two, the development stage
being discussed only as far as was necessary to draw attention to the improvements
made in method as a result of using the particular diagram or form being
demonstrated.
It will now be appropriate to study a little more closely the manner in which
improved methods can be developed.
One of the rewards of method study is the large saving which can often be
made from quite small changes and inexpensive devices, such as chutes or suitable
jigs.
An example of this is a small spring-loaded table, very cheaply made in
plywood, for removing the tiles from an automatic tile-making machine. The spring
was so calibrated that, each time a tile was pushed on to it by the machine, it was
compressed until the top of the tile dropped to the level of the machine platform so
that the table was ready to receive the next tile. This enabled the girl operating the
machine to concentrate on loading the finished tiles on to a rack ready for firing while
the new stack was piling up. When about a dozen tiles were in place, she was able to
lift them off the table, which immediately sprang up to the level of the machine plat-
form ready to receive the first tile of the next stack. This very simple device enabled
the second operative formerly employed on this operation to be released for other
work, an important feature in an area where skilled tile-pressers were diffrcult to ob-
tain.
In many manufacturing plants the work study man may have to go beyond
the study of the movements of materials and workers if he is going to make the most
effective contribution to increased productivity. He must be prepared to discuss with
the designers the possibility of using alternative materials which would make the
product easier and quicker to manufacture. Even if he is not an expert in design-and,
indeed, he cannot be expected to be-drawing attention to the possibilities of an alter-
native may put ideas into the minds of the designers themselves which they had 175
 METHODS AND MOVEMENTS AT THE WORKPLACE

previously overlooked. After all, like everyone else, they are human and often hard-
worked, and there is a strong temptation to specify a given material for a given
product or component simply because it has always been used in the past.
Apart from the elimination of obviously wasteful movements-which can
be done from the flow diagram or process chart-the development of improved
methods calls for skill and ingenuity. It is likely to be more successful if the work
study man is also well acquainted with the industry with which he is concerned. In any
but the simplest manual operations, he will have to consult with the technical or super-
visory staff and, even if he does know the right answer, it is better that he should do
so, since a method which they have taken part in developing is likely to be accepted
more readily than one which is introduced as someone else's idea. The same is true of
the operatives. Let everyone put forward his ideas-two heads are better than one!
The fact that really successful methods improvement is a combined opera-
tion is being increasingly recognised. Many organisations,large and small, have set up
groups for the improvement of manufacturing and operating methods. These groups
may be permanent or set up for some particular job such as the reJaying out of a shop
or factory, or the organisation of work. Such groups often decide on the division and
allocation of work as well as other related functions such as the control of quality.
In the United Kingdom Joseph Lucas Ltd, manufacturers of electrical
equipment and motor car accessories, have developed similar groups at various levels
which consider every aspect of manufacturing effrciency from designing the product
for more economic production onwards through all the processes and methods.

14. The methods laboratory

There is great value in having a small room or shop where the work study
men can develop and try out new methods. It need not be elaborate or expensive;
many devices can be tried out in wood before they are manufactured in metal. If the
scale of the work study activities justifies it, one or two good all-round craftsmen can
be seconded to this laboratory with some simple tools, such as a drill press and sheet-
metal equipment, together with a good operative from the production shops who will
try out the different'ogadgets" in collaboration with the work study staff until the best
method has been found. Having such a place saves interfering with the production
shops or the plant engineer's department when things are wanted in a hurry, and the
work study staff feel much freer to try out revolutionary ideas. New methods can be
demonstrated to the management, foremen and operatives, who can be encouraged to
try them out and make suggestions to be incorporated in the final version.
Do not let the work study shop become the place where everyone in the
works comes when they "want a little job done quickly" or private repairs executed.
There is a real danger of this, as more than one company has discovered.
On no account may the operative attached to the work study shop be used
for the setting of time standards. It is quite acceptable to time him in order to compare
the effectiveness of different methods, but time studies for standard setting must
176 always be made in the shops under production conditions with regular operatives.
 Chapterfz
DefitrG, install, maintain

1. Obtaining approval for the improved method

Once a complete study of the job has been made, and the preferred new
method developed, it is generally necessary to obtain the approval of the works
management before proceeding to install it. The work study man should prepare a
report giving details of the existing and proposed methods and should give his reasons
lor the changes suggested.
The report should show-
( l) Relative costs in material, labour and overheads of the two methods, and the sav-
ings expected.
(2) The cost of installing the new method, including the cost of any new equipment
and of re-laying out shops or working areas, if this is required.
(3) Executive actions required to implement the new method.

Before it is finally submitted, the report should be discussed with the

departmental supervision or management; if the costs of the change are small and all
are agreed that it is a useful change, the work may proceed on the authority of the
departmental manager or foreman.
If capital
expenditure is involved, such as the purchase of material-handling
equipment, or if complete agreement cannot be obtained from everyone concerned on
the desirability of the change, the matter may have to be decided on by the manage-
ment. In this case, it is almost certain that the work study man will be called upon to
justify his estimates. If capital investment is involved to any extent, he will have to be
able to convince doubting people, often non-technical, that it will really be justified.
Great care must therefore be taken in preparing such estimates, since a failure to live
up to them may damage both the work study man's own reputation and that of work
study itself.

2. Defining the imProved method

THE WRITTEN STANDARD PRACTICE

For all jobs other than those performed on standard machine tools or
specialised machines where the process and methods are virtually controlled by the 177
 DEFINE, INSTALL, I\4AINTAIN

machine, it is desirable to prepare a written standard practice, also known as an

"operative instruction sheet". This serves several purposes:
(1) It records the improved method for future reference, in as much detail as may be
necessary.
(2) Itcan be used to explain the new method to the management, foremen and
operatives. It also advises all concerned, including the works engineers, of any
new equipment required or of changes needed in the layout of machines or
workplaces.
(3) It is an aid to training or retraining operatives and can be used by them for
reference until they are fully conversant with the new method.
(4) It forms the 6asis on which time studies may be taken for setting standards,
although the element breakdown (see Chapter 16, section 6) will not necessarily
be the same as the breakdown of motions.

The written standard practice outlines in simple terms the methods to be

used by the operative. Therbligs and other method study symbols should not be used.
Three sorts of information will normally be required-

( l) The tools and equipment to be used and the general operating conditions.
(2) A description of the method. The amount of detail required will depend on the
nature of the job and the probable volume of production. For a job which will oc-
cupy several operatives for several months, the written standard practice may
have to be very detailed, going into fltnger movements.
(3) A diagram of the workplace layout and, possibly, sketches of special tools, jigs or
fixtures.

A very simple written standard practice for the operation studied in Chapter
I l, section 7 (cutting glass tubes to length), is illustrated in figure 63. The same princi-
ple is followed in more complex cases. In some of these the description may run into
several pages. The workplace layout and other diagrams may have to be put on a
separate sheet. With the more widespread use in recent years of standardised printed
sheets for process charts, it is becoming common practice to attach a fair copy of the
appropriate process chart to the written standard practice, whenever the simple
description entered thereon does not constitute a complete definition of the method.

3. lnstalling the imProved method

The final stages in the basic procedure are perhaps the most diflicult of all.
It is at this point that active support is required from the management and trade
unions alike. It is here that the personal qualities of the work study man, his ability to
explain clearly and simply what.he is trying to do and his gift for getting along with
other people and winning their trust become of the greatest importance.
lnstallation can be divided into five stages, namely-
178 (1) Gaining acceptance of the change by the departmental supervision.
 DEFINE, INSTALL, MAINTAIN

Figure 63. Standard practice sheet

ANDARD PRACTICE H E
PRODUCT: EOUIPMENT
3 mm diam. glsss tube, Jig No.231
supplied in 1 metrc Half-tound l5 cm
lengths
OPERATION:
File and brcak to lengths
ol f .5 cm (supprr o, iub!.)
| | l-llts
Tubc uroP dalrvcry
b, GhutG

Bor und.rn.ath.
WORKING CONDITIONS:
Light good Opsrative's siool'

LOCATION: Fittins shop :. STUO|ES NOS.

OPERATIVE: CLOCK No.54 CHARTED BY: '2_ '3. DATE
APPROVED BY: DATE

ET LEFT HAND RIGHT HAND EL

1 fake lube between thumb and litst two lingorc: push lotward Hold file: wait fot L.H.
to slop

2 Rotate tube between thumb and fingarc Notch tuba all round with adge ol lile hatd up against 2
lace ol iig

3 Hold tube fap notched ond ol tubs sharply with lite so that it latts 3
into chute

179
 DEFINE. INSTALL, MAINTAIN

(2) Gaining approval of the change by the management.

These two steps have already been discussed. There is little point in trying
to go any further unless they have been successful.
(3) Gaining acceptance of the change by the workers involved and their represen-
tatives.
(4) Retraining the workers to operate the new methods.
(5) Maintaining close contact with the progress of the job unr.il satisfied that it is run-
ning as intended.
If
any changes are proposed which affect the number of workers employed
in the operation-as is often the case-the workers' representatives should be con-
sulted as early as possible. Plans for any displacement of labour must be very care-
fully worked out so that the least possible hardship or inconvenience is caused.
Remember, even on a one-man operation, the worker in a workshop or any other
organisation does not work in isolation. If he is not a member of a team for the
specific purpose of his job, he is a member of a section or department; he gets used to
having the same people working around him, to spending his meal breaks with the
same "gang". Even if he is too far away from them to carry on a conversation during
his work, he can see them; he can, perhaps, exchange a joke with them from time to
time or grouse at the management or the foreman. He adjusts his personality to them
and they to him. If he is suddenly moved, even if it is only to the other end of the shop,
his social circle is broken up, he feels slightly lost without them and they without him.
In the case of a team or gang working together, the bonds are far stronger;
and breaking up such a team may have serious effects on productivity, in spite of
improved methods. It is only since the 1930s that the importance of group behaviour
in a working area has come to be recognised. Failure to take this into account may
lead the workers to resist changes which they would otherwise accept
It is in carrying out the first three steps of installation that the importance of
preliminary education and training in work study for all those likely to be concerned
with it-management, supervisors and workers' representatives-becomes evident.
people are much more likely to be receptive to the idea of change if they know and
understand what is happening than if they are merely presented with the results of a
sort of conjuring trick.
Where redundancy or a transfer are not likely to be involved, the workers
are much more likely to accept new methods if they have been allowed to share in
their development. The work study man should take the operative into his confidence
from the start, explaining what he is trying to do and why, and the means by which he
expects to do it. If the operative shows an intelligent interest, the uses of the various
tools of investigation should be explained. The string diagram is one of the most useful
of these in gaining interest: most people like to see their activities portrayed, and the
idea that he walks so far in the course of a morning's work is often a surprise to the
worker and makes him delighted with the idea of reducing his efforts. Always ask the
worker for his own suggestions or ideas on improvements that can be made, and
wherever they can be embodied, do so, giving him the credit for them (major sugges-
tions may merit a monetary reward). Let him play as full a part as possible in the
180 development of the new method, until he comes to feel it is mainly or partly his own.
 DEFINE, INSTALL, MAINTAIN

It may not always be possible to obtain very active co-operation from un-
skilled personnel, but even they usually have some views on how their jobs can be
made easier-or less subject to interruption-which may give important leads to the
work study man in reducing wasted time and effort.
Wholehearted co-operation at any level will only come as the result of con-
fidence and trust. The work study man must convince the management that he knows
what he is doing. He must have the respect of the supervisors and technicians, and
they must realise that he is not there to displace them or show them up, but as a
specialist at their disposal to help them. Finally, he must convince the workers that he
is not going to harm them.
Where there is deep-rooted resistance to change, it may be necessary to
decide whether the savings likely to be made by adopting the new method justify the
time and trouble involved in putting the change through and retraining older
operatives. It may be cheaper to concentrate on new trainees and let the older workers
continue to work in the way they know.
In gaining the trust of the workers, the work study man will find that they
will tend to turn to him for decisions rather than to the foreman (a danger already dis-
cussed). This situation must not be allowed to arise. The work study man must make
certain from the first that everyone understands that he cannot give executive deci-
sions and that the instructions concerning the introduction and application of the new
methods must come from the foreman to the worker in the first instance. Only then
can he proceed.

4. Training and retraining operatives

The extent to which the workers require retraining will depend entirely on
the nature of the job. It will be greatest in the case of jobs involving a high degree of
manual dexterity which have long been done by traditional methods. In such cases it
may be necessary to resort to films to demonstrate the old and the new methods and
the manner in which movements should be made. Each job will have to be treated on
its merits.
In the training or retraining of operatives, the important thing is to develop
the habit of doing the job in the correct way. Habit is a valuable aid to increased
productivity as it reduces the need for conscious thought. Good habits can be formed
just as easily as bad ones.
Beginners can be taught to follow a numbered sequence illustrated on a
chart or they may be taught on the machine itself. Either way, they must be made to
understand the reason for every movement. Still pictures together with instruction
sheets have proved very successful. Film strips can also be used.
Films are particularly valuable when retraining. When old habits have to be
brokeno it may be found that the operative is quite unaware of what he is doing. A
film in slow motion will enable him to see his exact movements and, once he knows,
he can start to learn the new method. It is important that the new method should be
really different from the old, otherwise the operative will tend to slip back into his old
ways, especially if he is not young and has spent many years doing the job. 181
 DEFINE. INSTALL, MAINTAIN

Figure 64. A typical learning curve

o
)
.=
E
U
J
()
o
CE
U
o-

tr

PRACTICE

ln learning a new series of movements, the operative gathers speed and

reduces the time required to perform them very quickly at first. The rate of improve-
ment soon begins to slow up, however, and it often requires long practice to achieve
really high and consistent speed, although the adoption of modern accelerated training
methods will considerably shorten the time needed. A typical "learning curve" is
shown in figure 64.
Experiments have shown that in the first stages of learning, to obtain the
best results, rests between periods of practice should be longer than the periods of
practice themselves. This situation alters rapidly, however, and when the operative has
begun to grasp the new method and to pick up speed, rest periods can be very much
shorter.
As part of the process of installation it is essential to keep in close touch
with the job, once it has been started, to ensure that the operative is developing speed
and skill and that there are no unforeseen snags. This activity is often known as "nurs-
ing" the new method, and the term is an apt one. Only when the work study man is
satisfied that the productivity of the job is at least at the level he estimated and that the
operative has settled down to it can it be left-for a time.

5. Maintaining the new method

It is important that, when a method is installed, it should be maintained in
its specified form, and that workers should not be allowed to slip back into old
methods, or introduce elements not allowed for, unless there is very good reason for
182 doing so.
 DEFINE, INSTALL, MAINTAIN

To be maintained, a method must first be very clearly defined and specified.

This is especially important where it is to be used for setting time standards for incen-
tive or other purposes. Tools, layout and elements of movement must be specified
beyond any risk of misinterpretation. The extent to which it is necessary to go into
minute details will be determined by the job itself.
Action by the work study department is necessary to maintain the applica-
tion of the new method because, human nature being what it is, workers and foremen
or chargehands will tend to allow a drift away from the method laid down, if there is
no check. Many disputes over time standards arise because the method being followed
is not the one for which the time was specified; foreign elements have crept in. If the
method is properly maintained, this cannot happen. If it is found that an improvement
can be made in the method (and there are very few methods which cannot be
improved in time, often by the operative himself), this should be officially incor-
porated, a new specification drawn up and new time standards set.

6. Conclusion
In this and the preceding chapters an attempt has been made to explain and
illustrate some of the more common methods of improving productivity through the
saving of wasted effort and time, and by reducing the work content of the process.
Good method studies will do more than this, because they will draw attention to waste
of material and waste of capital invested in equipment.
In the chapters which follow, we shall discuss work measurement. This is
one of the principal tools of investigation by which sources of ineffective time can be
disclosed. It is also the means of setting time standards on which planning and control
of production, incentive schemes and labour cost control data can be based. All these
are powerful tools for reducing ineffective time and for raising productivity.

183
 Partthree
Workmeasurement
 General remarks
on work measurement

1. Definition
In Chapter 4 it was said that work study consists of two complementary
techniques-method study and work measurement.In that chapter both were defined,
and before we go on to discuss work measurement it is worth while repeating the
definition of that technique given there.

We shall have occasion to examine several features of this carefully

thought-out definition in more detail in later chapters. For instance, the reader will
have noted the references to
ooa
qualified worker", and to ooa defined level of perfor-
mance". We need not coficern ourselves with the exact meaning of these terms for the
moment. It is worth noting, however, that the term 'owork measurement", which we
have referred to hitherto as a technique, is really a term used to describe a family of
techniques, any one of which can be used to measure work, rather than a single
technique by itself. The principal techniques which are classed as work measurement
techniques are listed in section 5 ofthis chapter.

2, The PurPose of work measurement

In Chapter 2 we discussed the way in which the total time of manufacture
of an article was increased by undesirable features of the product itself, by bad opera-
tion of the process and by ineffective time added in the course of production owing to
shortcomings on the part of the management or to actions of the workers. All these
factors tended to reduce the productivity ofthe enterprise.
In Chapter 3 we discussed the management techniques by which these fac-
tors could be eliminated or, at any rate, reduced. Method study has been shown to be
one of the principal techniques by which the work involved in the product or the pro-
cess could be decreased by the systematic investigation and critical examination of exist-
ing methods and processes and the development and installation of improved methods. 187
 Reference to figures 4 and 5 (pp. 19 and 23) shows, however, that the
reduction of the actual work involved in the product or the process to the minimum
possible takes us only part of the way towards achieving maximum productivity from
the resources of manpower and plant available. Even if the essential work is reduced
to the minimum, there is quite likely to be a great deal of unnecessary time taken in the
course of manufacture, due to the failure of the management to organise and control
as efficiently as it might; and, beyond that, further time is likely to be wasted through
the action or inaction of workers.
Method study is the principal technique for reducing the work involved,
primarily by eliminating unnecessary movement on the part of material or operatives
and by substituting good methods for poor ones. Work measurement is concerned
with investigating, reducing and subsequently eliminating ineffective time, that is time
during which no effective work is being performed, whatever the cause.
Work measurement, as the name suggests, provides the management with a
means of measuring the time taken in the performance of an operation or series of
operations in such a way that ineffective time is shown up and can be separated from
effective time. In this way its existence, nature and extent become known where
previously they were concealed within the total. One of the surprising things about
factories where work measurement has never been employed is the amount of ineffec-
tive time whose very existence is unsuspected-or which is accepted as "the usual
thing" and something inevitable that no one can do much about-that is built into the
process. Once the existence of ineffective time has been revealed and the reasons for it
tracked down, steps can usually be taken to reduce it.
Here work measurement has another role to play. Not only can it reveal the
existence of ineffective time; it can also be used to set standard times for carrying out
the work, so that, if any ineffective time does creep in later, it will immediately be
shown up as an excess over the standard time and will thus be brought to the attention
of the management.
Earlier it was mentioned that method study can reveal shortcomings of
design, material and method of manufacture, and, as such, affects mainly technical
people. Work measurement is more likely to show up the management itself and the
behaviour of the workers. Because of this it is apt to meet with far greater resistance
than method study. Nevertheless, if the efficient operation of the enterprise as a whole
is being sought, the application of work measurement, properly carried out, is one of
the best means of achieving it.
It is unfortunate that work measurement-and in particular time study, its
principal technique-acquired a bad reputation in the past, especially in trade union
circles. This was because in many early applications it was directed almost exclusively
to reducing the ineffective time within the control of the operatives by setting stan-
dards of performance for them, while the ineffective time within the control of the
management was virtually ignored. The causes of ineffective time over which the
management has some control are much more numerous than those which lie within
the direct control of the workers. Furthermore, experience has shown that, if causes. of
ineffective time such as hold-ups due to lack of raw materials or to plant breakdowns
are allowed to go on without real efforts being made to eliminate them, operatives tend
188 to get discouraged and slack, and "workers' ineffective time" increases. This is only to
 o'Well, if we are going
be expected: the attitude taken by the workers is, quite simply:
to be stopped from doing our jobs by something which we can do nothing about and
which it is the management's job to put right, why should we work harder? Let the
management put its own house in order first." It is an argument that can hardly be
countered.
Just as method study should precede work measurement in any reorganisa-
tion that takes place, so must the elimination of ineffective time due to management
shortcomings precede any attack on the ineffective time within the control of the
workers. Indeed, the mere fact of reducing the hold-ups and stoppages within the con-
trol of the management will tend to reduce the waste of time by the operatives,
because they will find themselves faced with proper supplies of work and of material,
and will have the general feeling that the management is "on its toes". This will in itself
have a beneficial effect without the application of incentive schemes or of any form of
coercion.
Work measurement may start a chain reaction throughout the organisation.
How does this come about?
The first thing to realise is that breakdowns and stoppages taking effect at
the shop floor level are generally only the end results of a series of management
actions or lailures to act.
Let us take an example of excessive idle time of an expensive machine,
revealed by a study taken over several days. This piece of plant is very productive
when operating but takes a long time to set up. It is found that a great deal of the idle
time is due to the fact that the batches of work being put on this machine are very
small, so that almost as much time is spent in resetting it to do new operations as is
spent in actual production. The chain of reactions resulting from this discovery may
be something like this:

n The work study department

+ reports that work measurement reveals that the machine is idle

for excessively long periods because of small orders coming from
the planning office. This is substantially increasing the cost of
manufacture. It suggests that the planning office should do some
proper planning and either combine several orders for the same
product into one large order or make more for stock.

tr The planning office

complains that it has to work on the instructions of the sales
+ office, which never seems to sell enough of any one product to
make up a decent-sized batch and cannot give any forecast of
future orders so that more can be made for stock.

u The sales office

says that it cannot possibly make forecasts or provide large
+ orders of any one product as long as it remains the policy of top
management to accept every variation that customers like to ask
for. Already the catalogue is becoming too large: almost every
job is now a "special". 189
 GENEBAT REMARKS ON WOHK MEASUREMENT

tr The managing director

when the effect of his marketing policy (or lack of it) on the
production costs is brought to his attention, is surprised and says
that he never thought of it like that; all he was trying to do was to
prevent orders going to his competitors by being as obliging to his
customers as possible.

One of the principal purposes of work study will have been served if the
original investigation leads the managing director to think again about his marketing
policy. Enthusiastic work study men may, however, find it well to pause a moment
and think about the fact that such chains of reaction tend to make someone ask:
"Who started this, anyway?" People do not like being "shown up". This is one of the
situations in which a good deal of tact may have to be used. It is not the work study
man's job to dictate marketing policy, but merely to bring to the attention of the
management the effect of that policy on the company's costs and hence on its com-
petitive position.
Thus it can be seen that the purposes of work measurement are to reveal the
nature and extent of ineffective time, from whatever cause, so that action can be taken
to eliminate it; and then to set standards of performance of such a kind that they will
be attainable only if all avoidable ineffective time is eliminated and the work is per-
formed by the best available method and by personnel suitable in training and ability
to their tasks.
We can now go on to discuss in greater detail the uses and techniques of
work measurement.

3. The uses of work measurement

Revealing existing causes of ineffective time through study, important
though it is, is perhaps less important in the long term than the setting of sound time
standards, since these will continue to apply as long as the work to which they refer
continues to be done and will show up any ineffective time or additional work which
may occur once they have been established.
In the process of setting standards it may be necessary to use work
measurement-
(1) To compare the efficiency of alternative methods. Other conditions being equal,
the method which takes the least time will be the best method.
(2) To balance the work of members of teams, in association with multiple activity
charts, so that, as nearly as possible, each member has a task taking an equal time
to perform (see Chapter.l0, section 4).
(3) fo determine, in association with man and machine multiple activity charts, the
number of machines an operative can run (see Chapter 10, section 4).
The time standards, once set, may then be used-
(4) To provide information on which the planning and scheduling of production can
be based, including the plant and labour requirements for carrying out the
190 programme of work and the utilisation of available capacity.
 GENERAL REMARKS ON WORK MEASUREMENT

(5) To provide information on which estimates for tenders, selling prices and delivery
promises can be based.
(6) To set standards of machine utilisation and labour performance which can be
used for any of the above purposes and as a basis for incentive schemes.
(7) To provide information for labour-cost control and to enable standard costs to be
fixed and maintained.

It is thus clear that work measurement provides the basic information

necessary for all the activities of organising and controlling the work of an enterprise
in which the time element plays a part. Its uses in connection with these activities will
be more clearly seen when we have shown how the standard time is obtained.

4. The basic procedure

In section 5 of Chapter 4 we described the basic steps of work study,
embracing both method study and work measurement. The basic procedure of
method study has been described separately in figure 2l (page 817 and in the text on
page 80. We shall now isolate those steps which are necessary for the systematic
carrying out of work measurement. These steps and the techniques necessary for
achieving them are shown diagrammatically in figure 65. They are-

tr SELECT the work to be studied.

u RECORD all the relevant data relating to the circumstances in

which the work is being done, the methods and the ele-
ments of activity in them.

tr EXAMINE the recorded data and the detailed breakdown criti-

cally to ensure that the most effective method and
motions are being used and that unproductive and
foreign elements are separated from productive ele-
ments;

tr MEASURE the quantity of work involved in each element, in

terms of time, usin9 the appropriate work measure-
ment technique.

t] COMPILE the standard time for the operation, which in the case
of stop-watch time study will include time allowances
to cover relaxation, personal needs, etc.
t] DEFINE precisely the series of activities and method of opera-
tion for which the time has been compiled and issue
the time as standard for the activities and methods
specified.
191
 GENERAL REMARKS ON WORK MEASUREMENI

Figure 65. Work measurement

Select, record, examine and measure quantity

of work performed using

predetermined
work stop-watch
sampling time study time standards
(PTS)

with allowances to get

to get standard standard time
time of operations of operations

COMPILE

to establish standard
data banks

It will be necessary to take the full range of steps listed above only if a time
is to be published as a standard. When work measurement is being used only as a tool
of investigation of ineffective time before or during a method study, or to compare the
effectiveness of alternative methods, only the first four steps are likely to be needed.

5. The techniques of work measurement

The following are the principal techniques by which work measurement is
carried out:
tr work sampling;
tr stop-watch time study;
D predetermined time standards (PTS);
tr standard data.
In the next few chapters we shall describe each of these techniques in some
192 detail.
 Ghapteg+
Worksampling

1. The need for work sampling

Work sampling (also known as "activity sampling", "ratio-delay study",
"random observation method", "snap-reading method" and "observation ratio study")
is, as the name implies, a sampling technique. Let us first see why such a technique
is needed.
In order to obtain a complete and accurate picture of the productive time
and idle time of the machines in a specific production area, it would be necessary to
observe continuously all the machines in that area and to record when and why any of
the machines were stopped. It would of course be quite impossible to do this unless a
large number of workers spent the whole of their time on this task alone-an un-
realistic proposition.
If it were possible to note at a glance the state of every machine in a factory
at a given moment, however, it might be found that, say, 80 per cent of the machines
were workin g and 20 per cent were stopped. If this action were repeated 20 or more
times at different times of the day and if each time the proportion of machines work-
ing was always 80 per cent, it would be possible to say with some confidence that at
any one time there were always 80 per cent of the machines working'
As it is not generally possible to do this either, the next best method has to
be adopted: that of making tours of the factory at random intervals, noting which
machines are working and which are stopped, and noting the cause of each stoppage.
This is the basis of the work sampling technique. When the sample size is large enough
and the observations made are indeed at random, there is quite a high probability that
these observations will reflect the real situation, plus or minus a certain margin of
error.
2. A few words about sampling
Unlike the costly and impractical method of continuous. observation, samp-
Iing is mainly based on probability. Probability has been defined as "the extent to 193
 which an event is likely to occur". A simple and oft-mentioned example that illus-
trates the point is that of tossing a coin. When we toss a coin there are two pos-
sibilities: that it will come down "heads", or that it will come down "tails". The law of
probability says that we are likely to have 50 heads and 50 tails in every 100 tosses of
the coin. Note that we use the term "likely to have". In fact, we might have a score of
55-45, say, or 48-52, or some other ratio. But it has been proved that the law becomes
increasingly accurate as the number of tosses increase. In other words, the greater the
number of tosses, the more chance we have of arriving at a ratio of 50 heads to 50
tails. This suggests that the larger the size of the sampleo the more accurate or
oopopulation", or group of items
representative it becomes with respect to the original
under consideration.
We can therefore visualise a scale where, at one end, we can have the com-
plete accuracy achieved by continuous observation and, at the other end, very doubt-
ful results derived from a few observations only. The size of the sample is therefore
important, and we can express our confidence in whether or not the sample is
representative by using a certain confidence level.

3. Establishing confidence levels

Let us go back to our previous example and toss five coins at a time, and
then record the number of times we have heads and the number of times we have tails
for each toss of these five coins. Let us then repeat this operation 100 times. The
results could be presented as in table 12, or graphically as in figure 66.

Tabte 12. Proportional distribution of "heads" and "taits" (lOO tosses of five coins at a time)

Combination Number of combinationr

Heads Tails
(p) (q)

5 0 3

4 I t1
3 2 30
2 3 30
I 4 L7

0 5 3

If we considerably increase the number of tosses and in each case toss a

large number of coins at a time, we can obtain a smoother curve, such as that shown
in figure 67.
This curve, called the curve of normal distribution, may also be depicted as
in figure 68. Basically, this curve tells us that, in the majority of cases, the tendency is
for the number of heads to equal the number of tails in any one series of tosses (when
p : q the number of tosses is a maximum). In few cases, however, is p markedly dif-
194 ferent from q due to mere chance.
 WOBK SAMPLING

Figure 66. Proportional distribution of "heads" and "tails" (1OO tosses of five coins at a time)

Number of
combinations

30

25

20-
t5
10

5-
p 0 'I 2 3 4 5
g 5 4 3 2 1 0
Combination

Curves of normal distribution may be of many shapes. They may be flatter,

or more rounded. To describe these curves we use two attributes: -x, which is the
average or measure of central dispersion; zind q which is the deviation from the
average, referred to as standard deviation. Since in this case we are dealing with a
proportion, we use qp to denote the standard error of the proportion.
The area under the curve of normal distribution can be calculated. In figure
68 one ap on both sides oflgives an area of 68.27 per cent of the total area; two qp
on both sides of x gives an area of 95.45 per cent and three qp on both sides ofTgives
an area of 99.73 per cent. We can put this in another way and say that, provided that
we are not biased in our random sampling, 95.45 per cent of all our observations will
fall within 7 + 2 ap and 99.73 per cent of all our observations will fall within 7 + 3 cp.

Figure 67. Distribution curve showing probabilities of combinations

when large samples are used

Combinations oI p and q
(from, say,p :
O, q :
100 top = 10O, S : 0) 195
 WORK SAMPLING

Figure 68. Curve of normal distribution

|t- 68.270/o

95.45o/o
99.73o/o

- 3o-x - 2o-x - 'l o-x

This is in fact the degree of confidence we have in our observations. To make things
easier, however, we tiy to avoid using decimal percentages: it is more convenient
to
speak of a 95 per ceni confidence level than of a 95.45 per cent confidence level' To
achieve this we can change our calculations and obtain-

95 per cent confidence level or 95 per cent of the area under the curve
: l'96 ap
gg per cent confidence level or 99 per cent of the area under the curve
: 2'58 ap
99.9 per cent confidence level or 99.9 per cent of the area under the curve
: 3'3 ap

In this case we can say that if we take a large sample at random we can be
confident that in 95 per cent of the cases our observations will
fall within + 1.96 cp'
and so on for the other values.
In work sampling the most commonly used level is the 95 per cent con-
fidence level.

4. Determination of samPle size

As well as defining the confidence level for our observations we have to
We must be
decide on the margin of error that we can allow for these observations'
oiwe are confident that for 95 per cent of the time this particular
able to say that:
other range of
observation is correct within * 5 per cent," or 10 per cent, or whatever
accuracy we may decide on.
Let us now return to our example about the productive time and the idle
the sample
time of the machines in a factory. There are two methods of determining
method' and the
size that would be appropriats for this example: the statistical
't96 nomogram method.
 WORK SAMPLING

STATISTICAL METHOD
The formula used in this method is-

cp: /Pq
/n
where
op : standard error ofproportion
p : percentage of idle time
Q : percentage of working time
n: number of observations or sample size we wish to determine.

Before we can use this formula, however, we need to have at least an idea of
the values of p and q.The first step is therefore to carry out a number of random
observations in the working area. Let us assume that some 100 observations were car-
ried out as a preliminary study and at random, and that these showed the machine to
be idle in 25 per cent of the cases (p : 25) and to be working 75 per cent of the time
(q :75). We thus have approximate values forp and q; in order now to determine the
value of n, we must find out the value of crp.
Let us choose a confidence level of 95 per cent with a l0 per cent margin of
error (that is, we are confident that in 95 per cent of the cases our estimates will be
+ l0 per cent ofthe real value).
At the 95 per cent confidence level
1.96 oP : l0
ap - 5 (approx.).
We can now go back to our original equation to derive n:

ap:

5:
75 observations.

If we reduce tt
".u.gin
*.rr; a * 5 per cent, we have
1.96 op: 5
cp: 2.5 (approx.)

2.5 :

n: (2.s)'

300 observations. 197

 WOBK SAMPLING

In other words, if we reduce the margin of error by half, the sample size will
have to be quadrupled.

NOMOGRAM METHOD
An easier way to determine sample size is to read off the number of obser-
vations needed directly from a nomogram such as the one reproduced in figure 69.
Taking our previous example, we draw a line from the "percentage occurrence"
ordinate p (in this case 25-75) to intercept the'oerror (accuracy required)' ordinate
(say, 5 per cent) and extend it until it meets the 'onumber of observations" ordinate r,
which it intercepts at 300 for the 95 per cent confidence level. This is a very quick
way of determining sample size.

5. Making random observations

Our previous conclusions are valid provided that we can make the number
of observations needed to attain the confidence level and accuracy required, and also
provided that these observations are made at random.
To ensure that our observations are in fact made at random, we can use a
random table such as the one in table 13. Various types of random table exist, and
these can be used in different ways. In our case let us assume that we shall carry out
our observations during a day shift of eight hours, from 7 a.m. to 3 p.m. An eight-
hour day has 480 minutes. These may be divided into 48 ten-minute periods.
We can start by choosing any number at random from our table, for exam-
ple by closing our eyes and placing a pencil point somewhere on the table. Let us as-
sume that in this case we pick, by mere chance, the number I I which is in the second
block, fourth column, fourth row (see table l3). We now choose any number between
I and 10. Assume that we choose the number 2; we now go down the column picking
out every second reading and noting it down, as shown below (if we had chosen the
number 3, we should pick out every third figure, and so on).

ll 38 45 87 68 20 ll 26 49 05

Looking at these numbers, we find that we have to discard 87, 68 and 49 because they
are too high (since we have only 48 ten-minute periods, any number above 48 has to
be discarded). Similarly, the second 1l will also have to be discarded since it is a
number that has already been picked out. We therefore have to continue with our
readings to replace the four numbers we have discarded. Using the same method, that
is choosing every second number after the last one (05), we now have

t4 l5 47 22

These four numbers are within the desired range and have not appeared before. Our
final selection may now be arranged numerically and the times of observation
throughout the eight-hour day worked out. Thus our smallest number (05) represents
the fifth ten-minute period after the work began at 7 a.m. Thus our first observation
198 will be at ?.50 a.m., and so on (see table l4).
 WORK SAMPLING

Table 13. Table of random numbers

49 54 43 54 82 t7 37 93 23 78 87 35 20 96 43 84 26 34 91 64
57 24 55 06 88 770/.744767 2t 76 33 sO 2s 83 92 t2 06 76
16 95 55 67 l9 98 l0 50 7l 75 t2 86 73 58 07 44 39 52 38 79
78 64 56 07 82 52 42 07 44 38 15 51 00 13 42 99 66 02 79 54
09 47 27 96 s4 49 t7 46 09 62 90 52 84 '17 27 08 02 73 43 28

44 |'t 16 58 09 '19 83 86 t9 62 06 76 50 03 l0 55 23 64 05 05
84 16 07 44 99 83 tt 46 32 24 20 14 85 88 45 l0 93 72 88 7l
82 97 't7 't't 81 o7 4s 32 t4 08 32 98 94 07 72 93 85 79 l0 75
so s2 26o. s7 00 56 76 31 38 80 22 02 53 53 86 60 42 04 53
83 39 50 08 30 42 34 07 96 88 54 42 06 87 98 35 85 29 48 39

40 33 20 38 26 13 89 51 03 74 t7 16 37 L3 04 07 74 2l t9 30
96 83 50 87 75 97 t2 25 93 47 70 33 24 03 54 91 1',| 46 44 80
88 42 95 45 72 16 64 36 16 00 04 43 r8 66 79 94 77 24 2t 90
33 27 t4 34 09 45 s9 34 68 49 t2 72 07 34 45 99 21 72 95 t4
50 27 89 87 19 20t537@49 52 85 66 60 44 38 68 88 ll 80

55 74 30 77 40 44 22 78 84 26 04 33 46 09 s2 68 07 97 06 57
59 29 97 68 60 7t 9t 38 67 54 t3 58 t8 24 76 15 54 55 95 52
48 55 90 65 72 96 57 69 36 tO 96 46 92 42 45 97 60 49 04 9t
66 31 32 20 30 7',1 84 57 03 29 l0 45 65 04 26 tt 04 96 67 24
68 49 69 I0 82 53 ?5 91 93 30 34 2s 20 s1 27 40 48 73 st 92

836264nt2 6't t9 N 7l 74 60 47 2t 29 68 02 02 37 03 3t
06 09 t9 '14 66 02 94 3't 34 02 76 70 90 30 86 38 45 94 30 38
33 32 5t 26 38 79 't8 45 04 9t t6 92 53 56 t6 02 75 s0 95 98
42 38 97 0t 50 87 75 66 8t 4t 40 0t 74 9t 62 48 51 84 08 32
96 44 33 49 t3 34 86 82 53 9r 00 52 43 48 8s 27 55 26 89 62

64 05 7l 95 86 lr 05 65 09 68 '16 83 20 37 90 57 16 00 ll 66
7s 73 88 0s 90 52 27 4t t4 86 22 98 t2 22 08 01 52 74 9s 80
33 96 02 75 t9 0't 60 62 93 55 59 33 82 43 90 49 37 38 44 59
97 5t 40 t4 02 04 02 33 31 08 39 54 16 49 36 47 95 93 13 30
15 06 15 93 20 0t 90 r0 75 06 40 78 78 89 62 02 67 74 t7 33

22 3s 85 15 33 92 03 5t 59 77 59 56 78 06 83 52 9r 05 70 74
09 98 42 99 64 6t 7t 62 99 t5 06 51 29 16 93 58 05 77 09 5t
54 87 66 47 54 73 32 08 tt t2 44 95 92 63 t6 29 56 24 29 48
58 37 78 80 70 42 tO 50 67 42 32 t7 5s 85 74 94 44 67 t6 94
87 59 36 22 4t 26 78 63 06 5s 13 08 27 0l s0 Ls 29 39 39 43

7t 4t 6t 50 72 12 4t 94 96 26 44 95 27 36 99 02 96 74 30 83
23 52 23 33 t2 96 93 02 t8 39 07 02 t8 36 07 2s 99 32 70 23
3t 04 49 69 96 l0 47 48 45 88 t3 4t 43 89 20 97 t7 t4 49 t7
31 99 73 68 68 35 81 33 03 76 2430124860 r8 99 t0 72 34
94 58 28 4t 36 45 37 59 03 09 90 35 s'.! 29 12 82 62 54 65 60

199
 WORK SAMPLING

Figure 69. Nomogram for determining number of observations

Percentage Error Number of
occurrence (accuracy required) observations
bt (nl

2000

4000
.50/o
I 600
3500
500
1
400
1
3000
1 300

12o,0
2500 1 100
2000 1 000

900
1.0 800

700
1 500
600
1 300
1 200
I 100 500
1 000
2.O 900 400
800

700

3.O 600
7 93

8 92 soo
o 9l 4.O
10 90
1I 89
o
12 88
13 a7
14 86 .o
15 85
16 84
l8 82 7.O
20 80
8.0
75 I'O
70 10
11
60
50 12
13
14
15

99 .80/o 95o/o
conlidence
200 level
 WORK SAMPLING

Table 14. Determining the sequence of time for random observations

Usable numbers as selected Arranged in numerical order Time of observationr

from the random table

lt 05 7.50 a.m.
38 ll 8.50 a.m.
45 r4 9.2O a.m.
20 15 9.30 a.m.
26 20 10.20 a.m.
05 22 10.40 a.m.
t4 26 I1.20 a.m.
l5 38 1.20 a.m.
47 45 2.30 a.m.
22 47 2.50 a.m.
'j Multiply each number by ten minutes and start from 7 a.m.

6. Conducting the study

DETERMINING THE SCOPE OF THE STUDY
Before making our actual observations, it is important that we decide on the
objective of our work sampling. The simplest objective is that of determining whether
a given machine is idle or working. In such a case, our observations aim at detecting
one of two possibilities only:

Observations

Machine working Machine idle

We can, however, extend this simple model to try and find out the cause of
the stoppage of the machine:

Observations

Machine working Machine idle

Waiting Waiting Personal

for for needs of
repairs supplies workers

Again, we may be interested in determining the percentage of time spent on

each activity while the machine is working:

Observations

Machine working Machine idle

Cutting Boring Filing 201

 WORK SAMPLING

Or perhaps we may wish to get an idea of the percentage distribution of

time when the machine is working and when it is idle, in which case we combine the
last two models.
We may also be interested in the percentage time spent by a worker or
groups of workers on a given element of work. If a certain job consists of ten different
elements, by observing a worker at the defined points in time we can record on which
element he is working and therefore arrive at a percentage distribution of the time he
has been spending on each element.
The objectives to be reached by the study will therefore determine the
design of the recording sheet used in work sampling, as can be seen from hgures 70,
7l and72.

MAKING THE OBSERVATIONS

So far we have taken the first five logical steps in conducting a work samp-
ling study. To recapitulate, these consist of-

tr Selecting the job to be studied and determining the objectives of the study.
tr Making a preliminary observation to determine the approximate values ofp
and q.
D In terms of a chosen confidence level and accuracy range, determining n
(the number of observations needed).
tr Determining the frequency of observations, using random tables.
tr Designing record sheets to meet the objectives of the study.

There is one more step to take: that of making and recording the observa-
tions and analysing the results. In making the observations, it is essential from the out-
set that the work study man is clear in his own mind about what he wants to achieve
and why. He should avoid ambiguity when classifying activities. For example, if the
engine of a fork-lift truck is running while the truck is waiting to be loaded or un-
loaded, he should decide beforehand whether this means that the truck is working or
idle. It is also essential for the work study man to contact the persons he wishes to
observe, explaining to them the purpose of the study, indicating to them that they
should work at their normal pace and endeavouring to gain their confidence and co-
operation.
The observation itself should be made at the same point relative to each
machine. The work study man should not note what is happening at the machines
ahead of him, as this tends to falsify the study. For example, in a weaving department
the observer may notice a loom that is stopped, just ahead of the one he is observing.
The weaver may have it running again by the time he reaches it. If he were to note it
as idle, he would be giving an untrue picture.
The recording itself, as can be seen, consists simply of making a stroke in
front of the appropriate activity on the record sheet at the proper and predetermined
time. No stop-watches are used.
The analysis of results can be calculated readily on the record sheet. It is
202 possible to find out the percentage of effective time compared with that of delays, to
 WORK SAMPLING

Figure 7O. Example of a simple work sampling record sheet

Date: Observer: Study No.:

Number of observations: 75 Total Percentage

Machine y4 ytfr yn xil wrt tfi yfr w l*il tltl lllf llfl ll 62 82.7
running

Machine
idle v(fi nt 13 17.3

Figure 71. Work sampting record sheet showing machine utilisation and distribution of idle time

Date: Observer: Study No.:

Number of observations: 75 Total Percentage

62 82.7
Machine running wfr[ yn yfr wil ltr ltil w
t4 wil [tI lll{ ll
Repairs 2 2.7
il

Machine
Supplies hlt 6 8.O

idle 't.3
Personal I
1

ldle 4 5.3
llil

Figure 72. Work sampling record sheet showing distribution of time on ten elements
of work performed by a group of four workers

Date: Observer: Study No.:

N umber of observations:
Elements of work

1 2 3 4 5 6 7 8 9 10

Worker No. 1

Worker No. 2
Worker No.3
Worker No. 4
203
 WORK SAMPLING

analyse the reasons for ineffective time and to ascertain the percentage time spent by a
worker, groups of workers or a machine on a given work element. These, in
themselves, provide useful information in a simple and reasonably quick way.

7. Using work sampling

Work sampling is widely used. It is a relatively simple technique that can
be used advantageously in a wide variety of situations, such as manufacturing, servic-
ing and offrce operations. It is, moreover, a relatively low-cost method and one that is
less controversial than stop-watch time study. The information derived from work
sampling can be used to compare the efficiency of two departments, to provide for a
more equitable distribution of work in a group and, in general, to provide the manage-
ment with an appreciation of the percentage of and reasons behind ineffective time. As
a result, it may indicate where method study needs to be applied, material handling
improved or better production planning methods introduced, as may be the case if
work sampling shows that a considerable percentage of machine time is spent idle,
waiting fbr supplies to arrive.

204
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 GhapterfS
Time study: The equipment

1. What is time study?

In Chapter l3 we listed the main techniques of work measurement. We shall
now examine, in the next few chapters, one of the most important of these techniques.
namely time study.

2. Basic time study equipment

If time studies are to be made, certain items of equipment are essential.
Basic time study equipment consists of-
tr a stop-watch;
tr a study board;
tr time study forms.

The studyman will need this equipment with him whenever he makes a time
study. In addition, in the study office there should be-

tr a small calculator;
tr a reliable clock, with a seconds hand;
tr measuring instruments such as a tape measure, steel rule, micrometer,
spring balance, and tachometer (revolution counter). Other measuring in-
struments may be useful, depending on the type of work being studied.

THE STOP-WATCH
Two types of watch are in general use for time study, namely the flyback
and the non-flyback types. A third type-the split-hand stop-watch-is sometimes
used. 2O5
 These watches may be obtained with any one of three graduated scales-
(l) Recording one minute per revolution by intervals of one-fifth of a second, with a
small hand recording 30 minutes.
(2) Recording one minute per revolution calibrated in l/l0fths of a minute, with a
small hand recording 30 minutes (the decimal-minute watch).
(3) Recording l/IOfth of an hour per revolution calibrated in l/10,000ths of an hour;
a small hand records up to one hour in 100 divisions (the decimal-hour watch).

It is also
possible to obtain watches with the main scale in decimal minutes
and an auxiliary scale outside it, usually in red, graduated in seconds and fifths of a
second.
A flyback decimal-minute stop-watch-probably the type in most general
use today-is shown in figure 73. The hand of the small dial makes l/30th of a
revolution for each revolution of the main hand, and thus makes a complete turn
every 30 minutes.
In this type of watch the movement is started and stopped by a slide (A) at
the side of the winding-knob (B). Pressure on the top of the winding-knob causes both
the hands to fly back to zero without stopping the mechanism, from which point they
immediately move forward again. If the slide is used, the hands can be stopped at any
point on the dial and restarted without returning to zero as soon as the slide is
released. This type of watch can be used for either "flyback" or "cumulative" timing
(see Chapter 16, section 9).

Figure 73. Decimal-minute stop-watch

A= Slide for stopping and starting the movement.

B= Winding knob. Pressure on this knob returns both
206 the hands to zero.
 TIME STUDY EOUIPMENT

The non-flyback type is controlled by pressure on the top of the winding-

knob. The first pressure starts the watch; the second pressure stops it; the third pres-
sure returns the hands to zero. This watch is suitable only for cumulative timing.
In the split-hand type of watch, pressing a secondary knob causes one of
the hands to stand still while the other continues to measure time. When the knob is
pressed a second time, the stopped hand returns to the moving one and the two go
on together. In this way, when a reading is takert a stopped hand is read instead of a
moving one, giving greater accuracy of reading.
The split-hand watch is easier to read, but is heavier, more expensive and,
because of its complexity, more troublesome to repair. With properly trained
studymen, equally good results can be obtained with a simpler, lighter and less expen-
sive watch. Unless there are special reasons for preferring one of the other types, the
single-pressure, centre-sweep hand, flyback watch with the main dial graduated in
l/l0fths of a minute and the smaller dial recording 30 minutes will be found most ser-
viceable for time study. This is the type illustrated in figure 73.
Whatever type of watch is used, it should always be remembered that it is a
delicate instrument which must be treated with care. Watches should be wound fully
before each study, and should be allowed to run down overnight. At regular intervals
they should be sent to a watchmaker for cleaning and routine overhaul.

THE STUDY BOARD

The study board is simply a flat board, usually of plywood or of suitable
plastic sheet, on which to place the forms for recording time studies. It should be rigid
and larger than the largest form likely to be used. It may have a fitting to hold the
watch, so that the hands of the work study man are left relatively free and the watch is
in a position to be read easily. For right-handed people the watch is normally placed
at the top of the board on the right-hand side, so that the board may be rested on the
left forearm with the bottom edge against the body and the forefinger or middle finger
of the left hand used to press the winding knob when resetting the watch (see figure
74). Some work study men prefer to attach their watches with strong rubber bands or
leather thongs around the two middle fingers of their left hands and to hold them at
the top of the board in that way. It is largely a matter of individual preference,
provided that the watch is securely held and can be easily read and manipulated. A
strong spring clip should also be fitted to the board to hold the forms on which the
study is recorded.
A study board which is either too short or too long for the studyman's arm
soon becomes tiring to use. Most studymen prefer therefore to have their own in-
dividual boards made up to fit their own arm lengths, after they have had sufficient
practice to know which size will be most comfortable.

3. Time study forms

Studies can be made on plain paper, but it is a nuisance having to rule up
new sheets every time a study is made. It is more convenient to have printed forms of
a standard size prepared, so that they can be filed neatly for reference, an essential 207
 TIME STUDY EOUIPMENT

Figure 74. Time study boards

(o) Study board for general purpose form

(b) Study board for short cycle form

208
 Printed-or cyclostyled-forms also ensure that
feature of well-conducted time study.
time studies are always made in a standard manner and that no essential data are
omitted.
The number of different designs of time study forms is probably not far
short of the number of work study departments in the world. Most experienced work
study men have their own ideas on the ideal layout. The examples shown in this book
represent designs which have been proved in practice to be satisfactory for general
work.
The principal forms used in time study fall into two groups: those used at
the point of observation while actually making the study, and which should therefore
be of a size to fit conveniently on the study board; and those which are used after the
study has been taken, in the study offtce.

FORMS USED ON THE STUDY BOARD

tr Time study top sheet: the top and introductory sheet of a study, on which is
recorded all the essential information about the study, the elements into
which the operation being studied has been broken down, and the break
points used. It may also record the first few cycles of the study itself. The
example shown in figure 75 has spaces in the heading for all the information
normally required about a study except the sketch of the workplace layout,
which should either be drawn on the reverse of the sheet, if the layout is
very simple, or should be drawn on a separate sheet (preferably of squared
paper) and attached to the study.
tr Continuation sheet: for further cycles of the study. An example is shown in
figure 76, from which it will be seen that the form consists only of the
columns and space for the study and sheet number. It is usual to print this
ruling on both sides of the paper; on the reverse side the heading is not
necessary.
These two forms are the ones most generally used. Together they are ade-
quate for most general time study work. For the recording of short cycle
repetitive operations, however, it is convenient to use a specially ruled form
instead.
tl Short cycle study form. Two examples of a short cycle form are illustrated.
That in figure 77 shows a simple type of form which serves very well for
most common short cycle work. The other, shown (front) in figure 78 and
(reverse) in figure 79, is a more complicated form, adapted from one in
general use in the United States; it may be more suitable if short cycle work
is the rule rather than the exception.

The international standard A4 size of paper is a good one to use for these
forms, as it is the biggest standard size which will fit conveniently on a study board.
Foolscap is generally found to be a little too long.

FORMS USED IN THE STUDY OFFICE

tr Working sheet: for analysing the readings obtained during the study and
obtaining representative times for each element of the operation. One exam- 209
 TIME STUDY EOUIPMENT

Figure 75. General-purpose time study top sheet

TIME STUDY TOP SHEET

DEPARTMENT: STUDY No.:
OPERATION: M.S. No.:
SHEET No.: OF
TIME OFF:
PLANT/MACHINE: No.: TIME ON:
ELAPSED TIME:
TOOLS AND GAUGES: UHtsHAIIVE:
CLOCK No.:
PRODUCT/PART: No.: STUDIED BY:
DWG. No.: MATERIAL DATE:
QUALITY: CHECKED:
,V.8. Skotch the WORKPLACE LAYOUT/SET-UP/PART on the rovsrse, or on a soparate shoet and attach

ELEMENT DESCRIPT]ON R. w.R. S.T. B.T. ELEMENT DESCilTTloN R. w.R, s.T. B.T.

N.B. R. = Rating. W. R. = Watch Reading. S.T. = Subtracted Time. B.T. = Basic Time.

210
 TIME STUDY EOUIPMENT

Figure 76. Continuation sheet for general-purpose time study (front)

srUDy No.: ITIME STUDY CONTINUATTON SHEET SHEET No. Ot

ELEMENT DESCRIPTION R. w.R. S.T. B.T. ELEMENT DESCRIPTION R. w.R. S.T. B.T.

N.B. Reverse side similar. but without upper line of heading.

211
 IIME STUDY EOUIPMENT

Figure 77. Simple type of short cycle study form

SHORT CYCLE STUDY FORM

DEPARTMENT: SECIIUN: STUDY No.
SHEET No.: OF:
OPERATION: M.S. No.: TIME OFF:
TIME ON:
PLANT/MACHINE: No. ELAPSED TIME:
OPERATIVE:
TOOLS AND GAUGES:
PRODUCT/PART: No. CLOCK No.:
DWG. No. MATERIAL: STUDIED BY:
DATE:
OUALITY: WORKING CONDITIONS:
CHECKED:

N.B. Sketch the workplace overleaf.

Et. Observed Time Total
ELEMENT DESCRIPTION 8g€ R B.T
No. 1 2 3 4 5 6 7 E I t0 o.T. o.T.

N.B. R = Rating. O.T. = Observed Time. B.T. = Basic Time.

212
 TIME STUDY EOUIPMENT

Figure 78. Short cycle study form (front)

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ple of a working sheet is shown in figure 100 in Chapter 20. As will be seen
later, there are various ways in which the analysis may be made, each re-
quiring a different ruling on the sheet. For this reason many studymen
prefer to use simple lined sheets, of the same size as the study sheets, for
making their analyses, clipping these to the study sheets when complete.
tr Study summary sheet: to which the selected or derived times for all the ele-
ments are transferred, with the frequencies of the elements' occurrence. This
sheet, as its name suggests, summarises neatly all the information which has
been obtained during the course of the study. The heading includes all the
details recorded about the operation at the top of the time study top sheet.
The completed study summary sheet is clipped on top of all the other study
sheets and is thus filed with them. The summary sheet should therefore be of
the same size as that chosen for the study sheets. An example is shown in
figure 80, from which it will be seen that the main body of the sheet has
space for the ruling of additional columns, should these be needed for the
particular study being summarised.
tr Analysis of studies sheet: on which are recorded, from the study summary
sheets, the results obtained in all the studies made on an operation. The
analysis of studies sheet records the results of all the studies made of a par-
ticular operation, no matter when they were made or by whom. It is from
the analysis of studies sheet that the basic times for the elements of the
operation are finally compiled. The sheet is often much larger than the
ordinary study forms. See figure 81, and figure 102 in Chapter 20.
! A specially ruled sheet for the compilation of Relaxation Allowances is also
often used.

The use of all these forms, both those employed when actually making the
study and those used afterwards to analyse and record it, will be described in detail in
subsequent chapters.

4. Other equipment
As well as the stop-watch, other timing devices are used when very accurate
measurement is required. They will not be discussed in detail in this book, as the stop-
watch provides the accuracy necessary for the work that most readers are likely to
undertake during the first few years of their application of work measurement tech-
niques. Two of them may, however, be mentioned.

(l) The motion picture camera running at a constant speed, the film being projected
at an equal constant speed.
(2) The time study machine. In this machine marks are made on a paper tape run-
ing at constant speed, by pressure ofthe fingers on two keys. Its only advantage
over the stop-watch is that it leaves the work study man free to observe the opera-
tion continuously instead of having to look at and read the watch. It also enables
very short elements to be timed. The tape has to be measured at the end of the
study. 215
 TIME STUDY EOUIPMENT

Figure 80. Study summary sheet

STUDY SUMMARY SHEET

UETAH IMEN I SEU I IUN: 5t uuY No.:
UTtsHAIIUN: M.5. NO.: SHEET No. OF:
UAI E:
I IME OFF
PI.ANT/MACHINE: No.: TIME ON:
EIIPSED TIME:
CHECK TIME:
TOOLS & GAUGES: NET TIME:
PRODUCT/PART: No.: OBS.TIME:
UNACC.TIME:
DWG. No.: MATERIAL:
U.T. AS %
OUALITY: WORKING CONDITIONS: STUDIED BY:
CHECKED:
OPERATIVE: M/F CLOCK No.
Sketch and Notes on back of Sheet 1

Et.
No. ELEMENT DESCRIPTION B.T. F. Obs

,ty.A. B.T. = Basic Time. F. = Frequency of occurrence per cycle. Obs. = No. of observations

216
 :uld 'H's/'u\t's EOUIPMENT

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 Among the equipment listed in section 2 was a reliable clock, with a seconds
hand, for use in the study office. Before leaving the office to make a study, the
studyman starts his stop-watch and notes on his study sheet the time by the office
clock at which he did so. If the studyman has a wrist-watch, this can be used instead,
provided that it is reliable. In any case it is often an advantage for the studyman to
have a wrist-watch, though not essential.
The time study office will need the usual clerical equipment-staplers,
It is very useful to
punches, files and cabinets of some sort to put them in, and so on.
have an oflice-type pencil sharpener fixed somewhere near the door of the study
office.
As well as the measuring equipment mentioned in section 2, other instru-
ments may be found useful in particular trades. One instrument with a fairly wide
application is the Servis Recorder, which can be attached to a machine or vehicle and
will then make a record of the times when the machine it is placed on is in motion, and
when stopped. A micrometer is often useful: reliable ones can now be obtained quite
cheaply. Thermometers and instruments to measure relative humidity are often essen-
tial.

218
 Time study: Selecting
and timing the iob

1. Selecting the job

As in method study, the first step in time study is to select the job to be stu-
died. Generally speaking, there are few occasions when a work study man can go into
a factory or a department and select a job at random. There is nearly always a reason
why a particular job requires attention. Some possible reasons are-
( l) The job in question is a new one, not previously carried out (new product, compo-
nent, operation or set of activities).
(2) A change in material or method of working has been made and a new time stan-
dard is required.
(3) A complaint has been received from a worker or workers' representative about the
time standard for an operation.
(4) A particular operation appears to be a "bottleneck" holding up subsequent opera-
tions and possibly (through accumulations of work in process behind it) previous
operations.
(5) Standard times are required before an incentive scheme is introduced.
(6) A piece of equipment appears to be idle for an excessive time or its output is low,
and it therefore becomes necessary to investigate the method of its use.
(7) The job needs studying as a preliminary to making a method study, or to compare
the efficiency of two proposed methods.
(8) The cost ofa particularjob appears to be excessive.

If the purpose of the study is the setting of performance standards, it should

not normally be undertaken until method study has been used to establish and define
the most satisfactory way of doing the job. The reason for this is obvious: if the best
method has not been discovered by systematic study, there is always the possibility
that a much better way of doing it may be evolved, either by the worker himself or by
technical staff-a way which may need considerably less work to achieve the results
required. The amount and nature of the reduction in work may vary at different times,
according to which worker happens to be doing the job and the method he chooses to
employ. The quantity of work involved in the process or operation may actually in-
crease, if an operative less skilled than the one originally timed does the job later on
and uses a method more laborious than that on the basis of which the time was set. 219
 TIME STUDY: SELECTING AND I

Until the best method has been developed, defined and standardised, the
amount of work which the job or process involves will not be stable. Planning of
programmes will be thrown out, and, if the time standard is used for incentive pur-
poses, the payment made to the operative may become uneconomic for the job. The
worker may find the time unattainable, or, in the opposite case, may find that he can
complete the work in a much shorter time than that set as the standard. If so, he will
very probably restrict his output to the maximum which he thinks the management
will tolerate without starting to make inquiries into the validity of the time standard
which has been set. Although, in collective agreements introducing work study, it is
customary to include a clause permitting the retiming ofjobs when the work content is
altered in either direction (and the management would, in theory, be justified in invok-
ing this clause where a reduction in work content has been made, whether by worker
or management), the retiming of jobs in such circumstances always tends to cause
resentment, and if it is done frequently it will quickly shatter the confidence of the
workers in both the competence of the work study staff and the honesty of the man-
agement. Therefore make sure first that the method is righl Remember, too, that any
one time should refer only to one specified method.
There are problems in the selection ofjobs to be studied which have nothing
to do with the importance of the jobs to the enterprise or the abilities of the operatives.
One diflicult problem which may arise in factories where a piecework system is
already in operation is that the existing piecework times on certain jobs, fixed by
bargaining or estimation, may be so liberal that the workers have been earning high
bonuses which cannot possibly be maintained if the jobs are properly reassessed.
Attempts to alter the methods, which should automatically bring about a reassess-
ment of the times allowed, may meet with such resistance that it is unwise to proceed
with the studies. If this is the case, it is better, in an initial application, to tackle a num-
ber of jobs where it is evident that the earnings of the workers can be increased by the
application of time study, even though these jobs may be less important to the
performance of the shop as a whole. When the rest of the shop has been studied
and confidence in the integrity of the work study man has been established, it may be
possible to return to the "problem" jobs. It will almost certainly be necessary to nego-
tiate on these problem jobs with the workers' representatives, and it may be necessary
to compensate the workers concerned. It is nevertheless possible to carry through
such negotiations successfully, if the purpose of the change is fully understood by all
concerned.

2. The approach to the worker

The question of relationships between the work study man and the super-
visors and workers in the enterprise was dealt with at some length in Chapter 5. The
reason for mentioning it here is that what was said about work study in general
applies with even more force to time study, especially with respect to the workers.
The purpose of a method study is usually obvious to everyone: it is to
improve the method of doing the job, and everyone can see that it is a proper activity
for the work study man to engage in. His efforts may even be welcomed by operatives,
220 if he succeeds in relieving them of fatiguing or unpleasant work. The purpose of a time
 TIME STUDY: SELECTING AND TIMING THE JOB

study is less obvious and, unless it is very carefully explained to everyone concerned,
its object may be completely misunderstood or misrepresented, with consequent un-
rest and even strikes.
It is assumed that the work study man has already become a familiar figure
in the shop while making method studies and that he is well known to the foreman and
the workers' representatives. Nevertheless, if no time studies have previously been
made there, he should hrst bring the workers' representatives and the supervisors
together and explain in simple terms what he is going to do and why, and should invite
them to handle the watch. All questions should be answered frankly. This is where the
value of work study courses for workers' representatives and foremen shows itself.
a choice of workers is available, it is good policy to ask the foreman and
If
workers' representatives to suggest the one most suitable to be studied first, emphasis-
ing that he should be a competent, steady person. His rate of working should be
average or slightly better than average. Some people are not temperamentally suited
to being studied and cannot work normally while being watched. They should be
avoided at all costs.
It is important, where the job is one likely to be done on a large scale (pos-
sibly by a large number of workers), to take studies on a number of qualified workers.
A distinction is made in time study practice between what are termed
representative workers and qualified workers. A representative worker is one whose
skill and performance is the average of the group under consideration. He is not neces-
sarily a qualified worker. The concept of the qualified worker is an important one in
time study. He is defined as follows:

There is a reason for this insistence on selecting qualified workers. In setting

time standards, especially when they are to be used for incentives, the standard to be
aimed at is one which can be attained by the qualified worker, and which can be main-
tained without carrsing him undue fatigue. Because workers work at different speeds,
observed times have to be adjusted by factors to give such a standard. These factors
are dependent on the judgement of the studyman. Experience has shown that ac-
curacy of judgement is attainable only within a fairly narrow range of speeds close to
that which is normal for a qualified worker. The study of slow or unskilled workers or
of exceptionally fast workers will tend to result in the setting of time standards that are
either unduly large (known as "loose" times), and hence uneconomic, or unduly short
(known as "tight" times), in which case they are unfair to the worker and will
probably be the subject of complaints later. 221
 TIME STUOY: SELECTING AND 1

When the worker whose work is to be studied first has been selected, he
should be approached in company with the foreman and the workers' representative.
The purpose of the study and what is required should be carefully explained. The
worker should be asked to work at his usual pace, taking whatever rest he is ac-
customed to take. He should be invited to explain any difficulties he may encounter.
(This procedure becomes unnecessary as soon as work study is firmly established and
its purpose well understood. It should, however, be carried out with new workers, and
new members of the work study staffshould be introduced to supervisors and workers
when they start studies). It is important to impress on the supervisor that the worker is
then to be left alone. Some workers are liable to became apprehensive if one of their
direct supervisors is standing over them and watching them.

If a new method has been installated the worker must be allowed plenty of
time to settle down before he is timed. The "learning curve" in figure 64 (page 000)
shows that it takes quite a long time for an operative to become adapted and to reach
his maximum steady speed. Depending on the duration and intricacy of the operation,
it may be necessary to allow a job to run for days or even weeks before it is ready to
be timed for the purpose of setting standards. In the same way, the work done by
new operatives should never be used for timing until they have grown thoroughly
accustomed to their jobs.

The position in which the studyman stands in relation to the operative is

important. He should be so placed that he can see everything the operative does
(especially the movements of his hands), without interfering with his movements or
distracting his attention. The studyman should not stand directly in front of him, nor
should he stand so close to him that he has the feeling of "having someone standing
over him"-a frequent complaint made against time study. The studyman's exact
position will be determined by the type of operation being studied, but the position
generally recommended is to one side of the operative, slightly to the rear and about 2
metres away. In this position the operative can see him by turning his head a little, and
they can speak if it is necessary to ask a question or explain some point in connection
with the operation. The study board and watch should be held well up in line with the
job, to make reading the watch and recording easy while maintaining continuous
observation.

On no account should any attempt be made to time the operative without

his knowledge, from a concealed position or with the watch in the pocket. It is dis-
honest and, in any case, someone is sure to see and the news will spread like wildfire.
Work study should have nothing to hide.
It is equally important that the studyman should stand up while making his
is
study. There a tendency on the part of workers to regard themselves as having to do
all the work while the studyman simply stands around and watches them. This will be
increased if the latter settles himself into a comfortable position. He will quickly lose
the workers' respect, which is his greatest asset. He should neither sit nor lean but
should hold himself comfortably in a position which he can maintain, if necessary,
over a long period. Time study demands intense concentration and alertness,
especially when timing very short "elements" or "cycles" (defined later in this chap-
222 ter), and it is generally agreed that this is better attained when standing.
 TIME STUDY: SELECTING AND TIMING THE JOB

Most operatives will quickly settle down to their normal working pace, but
nervous workers, especially women, have a tendency to work unnaturally fast, which
will cause them to fumble and make errors. If this happens, the studyman should stop
the study and have a chat with the operative to put him at his ease, or even leave him
to settle down for a bit.

More difficult to cope with is the o'clever" worker who sets out to'oput one
across" the studyman. This is most likely to occur where it is known that the time
standard to be set will be used as a basis for an incentive. The operative will go un-
naturally slowly or insert unnecessary movements in the hope of getting a "looser"
(longer) time. Some workers, usually the young ones, may do so out of devilment in
order to match their wits against those of the studyman. It is hard to blame them,
because many industrial jobs are dull enough in all conscience, and the battle adds a
little spice to life! Nevertheless, from the studyman's point of view they are a nuisance.

On repetitive work it is generally easy to detect operatives who are

deliberately working at a pace which is not natural to them because, if they are work-
ing naturally, there will be very little variation in the times of the different cycles once
they have got going, whereas it is diflicult for them to control their cycle times when
they are not. When there are wide variations in successive cycle times, and when these
are not due to variations in the material being worked on or to the tools or machine (in
which case the studyman should report the variations to the proper authorities), the
differing cycle times must be due to action on the operative's part. If this is the case,
the studyman should discontinue the study and see the shop foreman. As a matter of
practical diplomacy it may be wiser not to report the operative for attempting to "pull
his leg", but to ask the foreman to come and look at the job as it does not seem to be
running quite right. This is the sort of human situation that must be dealt with
according to its merits if the studyman is not going to risk making himself unnecess-
arily unpopular, and is one of the reasons why the personal qualities of the studyman
listed in Chapter 5 are so essential.

When technical considerations have a considerable influence on the job be-

ing studied, it may be much less easy to detect attempts to stretch the time of the job,
unless the studyman himself is an expert is the process. This is especially so where
craft skill is involved (as in some sheet-metal work, or turning and screw-cutting
operations to fine tolerances and high finish on centre lathes), even where speeds and
feeds have been specified by the process planning department. It is dfficult to argue
with a skilled craftsman if you are not one yourselfl This is one of the reasons why it
is so important to establish precisely the method and conditions of an operation
before attempting to time it. A really good method study before the job is timed sim-
plifies immensely the task of setting time standards.

In the foregoing paragraphs an effort has been made to suggest some of the
practical problems the studyman will have to face in obtaining representative times;
but there are many others which can be learned only in the hard school of experience,
in the atmosphere of the workshop, among the men and women who work there. They
cannot be translated into print. The human-hearted man will delight in them; the
other sort should not become study men! 223
 TIME STUDY: SELECTING AND TIMING THE JOB

3. Steps in making a time study

When the work to be measured has been selected, the making of a time
study usually consists of the following eight steps (see also figure 65):

( l)
Obtaining and recording all the information available about the job, the operative
and the surrounding conditions, which is likely to affect the carrying out of the
work.
(2) Recording a complete description of the method, breaking down the operation
into "elements".
(3) Examining the detailed breakdown to ensure that the most effective method and
motions are being used, and determining the sample size.
(4) Measuring with a timing device (usually a stop-watch) and recording the time
taken by the operative to perform each "element" of the operation.
(5) At the same time, assessing the effective speed of working of the operative relative
to the observer's concept ofthe rate corresponding to standard rating.
(6) Extending the observed times to "basic times".
(7) Determining the allowances to be made over and above the basic time for the
operation.
(8) Determining the "standard time" for the operation.

4. Obtaining and recording information

The following information (or those items which apply to the operation be-
ing studied) should be recorded from observation before starting the study proper. It is
usual to do so on the time study top sheet. If the various headings are printed or sten-
cilled, this helps to ensure that no vital piece of information is overlooked. The exact
number of the items listed below which may have to be included when a time study
form is designed will depend on the type of work carried out in the undertaking in
which it is to be used. In non-manufacturing industries such as transport and catering,
it should not be necessary to include space for the ooproduct", etc. Factories where all
the work is manual will require space for "tools" but not for "plant or machine".
Details of the workplace can be recorded more quickly and with greater
accuracy when they are photographed with a simple instant-print-type camera with
flash attachment (even the simplest cameras of this type are now equipped with auto-
matic exposure control).
The filling-in of all the relevant information from direct observation is im-
portant in case the time study has to be referred to later; incomplete information may
make a study practically useless a few months after it has been made. The forms
shown in figures 75 to 79 are designed for manufacturing industry to show the maxi-
mum amount of information that is usually necessary.
224 The information to be obtained may be grouped as follows:
 :LECTING AND TIMING THE JOB

A. Information to enable the study to be found and identified quickly when

needed
Study number.
Sheet number and number of sheets.
Name or initials of the studyman making the study.
Date of the study.
Name of the person approving the study (head of the work study depart-
ment, production manager or other appropriate executive).

B. Information to enable the product or part being processed tb be identified

accurately
Name of product or part.
Drawing or specification number.
Part number (if different from drawing number).
Material.
Quality requirements.r

C. Information to enable the process, method, plant or machine to be accu-

rately identified
Department or location where the operation is taking place.
Description of the operation or activity.
Method study or standard practice sheet numbers (where they exist).
Plant or machine (maker's name, type, size or capacity).
Tools, jigs, fixtures and gauges used.
Sketch of the workplace layout, machine set-up and/or part showing sur-
faces worked (on the reverse of the time study top sheet, or on a separate
sheet attached to the study if necessary).
Machine speeds and feeds or other setting information governing the rate of
production of the machine or process (e.g. temperature, pressure, flow, etc.).
It is good practice to have the foreman initial the study form beside the
record of information of this sort, as an endorsement of its correctness.

D. Information to enable the operative to be identified

Operative's name.
Clock number.2

I In the case of some engineering products, parts may be modified from time to time and the drawings
reissued. It may therefore also be necessary to note the issue number.
For "Quality requirements" it may simply be suflicient to put a standard specification number or
"Good finish". In engineering practice, tolerances and finish are generally specified on the drawing.
2
In the case ofnewjobs or new operatives, it may be desirable to note the amount ofexperience the
operative has had on the particular operation at the time ofthe study, so that the point that they have reached on
the learning curve (see figure 64) may be assessed. 225
 TIME STUDY: SELECTING AND TIMING THE JOB

E. Duration of the study

The start of the study ('Time on").
The finish of the study ('Time off').
Elapsed time.

F. Working conditions
Temperature, humidity, adequacy of the lighting, etc., in supplement to the
information recorded on the sketch of the workplace layout.

5. Checking the method

Before proceeding with the study, it is important to check the method being
used by the operative. If the study is for the purpose of setting a time standard, a
method study should already have been made and a written standard practice sheet
completed. In this case it is simply a question of comparing what is actually being
done with what is specified on the sheet. If the study is being made as the result of a
complaint from a worker that he is unable to attain the output set by a previous study,
his method must be very carefully compared with that used when the original study
was made. It will often be found in such cases that the operative is not carrying out
the work as originally specified: he may be using different tools, a different machine
set-up or different speeds and feeds, temperatures, rates of flow or whatever the re-
quirements of the process may be, or additional work may have crept in.

Itmay be that the cutting tools are worn, or have been sharpened to incor-
rect profiles. Times obtained when observing work carried out with worn tools or in-
correct process conditions should not be used for the compilation of time standards.

In highly repetitive short cycle work, such as work on a conveyor band

(light assembly, packing biscuits, sorting tiles), changes in method may be much more
dfficult to deiect, since they may involve changes in the movements of the arms and
hands of the operative ('motion patterns") which can be observed only with diffrculty
by the naked eye and require special apparatus to analyse.

Although it has been emphasised repeatedly in this book that a proper

method study should be made before a time study is undertaken for the purpose of set-
ting time standards, there are occasions when time standards may have to be set
without a full-scale method study being conducted beforehand. This is most likely to
occur with short-run jobs which are only done a few times a year in the shop con-
cerned. In such cases the studyman should make a careful record of the method by
which the job is being done, after putting right any obvious ineffrciencies-in
organisation, for instance, by providing containers for finished work in the proper
positions or by checking machine speeds. This record becomes especially important as
it *ru be the only record available, and changes in methods will be more likely to
226 occur where operatives have not been instructed in one definite method.
 6. Breaking the job into elements
Once the studyman has recorded all the information about the operation
and the operative needed for proper identification in the future, and has satisfied
himself that the method being used is the correct one or the best possible in the
prevailing circumstances, he must start to break it down into elements.

A work cycle starts at the beginning of the first element of the operation or
activity and continues to the same point in a repetition of the operation or activity.
That is the start of second cycle. This is illustrated in the fully worked-out example of
a time study in Chapter 20.
A detailed breakdown into elements is necessary-
( l) To ensure that productive work (or effective time) is separated from unproductive
activity (or ineffective time).
(2) To permit the rate of working to be assessed more accurately than would be poss-
ible if the assessment were made over a complete cycle. The operative may not
work at the same pace throughout the cycle, and may tend to perform some ele-
ments more quickly than others.
(3) To enable the different types of element (see below) to be identified and dis-
tinguished, so that each may be accorded the treatment appropriate to its type.
(4) To enable elements involving a high degree of fatigue to be isolated and to make
the allocation of fatigue allowances more accurate.
(5) To facilitate checking the method so that the subsequent omission or insertion of
elements may be detected quickly. This may become necessary if at a future date
the time standard for the job is queried.
(6) To enable a detailed work specification (see Chapter 23) to be produced.
(7) To enable time values for frequently recurring elements, such as the operation of
machine controls or loading and unloading workpieces from fixtures, to be ex-
tracted and used in the compilation of standard data (see Chapter 22). 227
 TIME STUDY: SELECTING AND TIMING THE JOB

TYPES OF ELEMENT
Eight types of element are distinguished: repetitive, occasional, constant,
variable, manual, machine, governing, and foreign elements. The deflrnition of each, as
given in the British Standards Institution's Glossary of terms in work study, op. cit.,
is listed below, together with examples-
tr A repetitive element is an element which occurs in every work cycle of the
job.
. Examples: the element of picking up a paft prior to an assembly operation;
the element of locating a workpiece in a holding device; putting aside a
flrnished component or assembly.

tr An occasional element is an element which does not occur in every work

cycle of the job, but which may occur at regular or irregular intervals.
Examples: adjusting the tension, or machine setting; receiving instructions
from the foreman. The occasional element is useful work and a part of the
job. It will be incorporated in the final standard time for the job.

tr A conitant element is an element for which the basic time remains constant
whenever it is performed.
Examples: switch on machine; gauge diameter; screw on and tighten nut;
insert a particular cutting tool into machine.

tr A variable element is an element for which the basic time varies in relation
to some characteristics of the product, equipment or process, e.g. dimen-
sions" weight, quality, etc.
Examples: saw logs with handsaw (time varies with hardness and diameter);
sweep floor (varies with area); push trolley of parts to next shop (varies with
distance).

tr A manual element is an element performed by a worker.

D A machine element is an element automatically performed by a power-
driven machine (or process).
Examples: anneal tubes, fire tiles; form glass bottles; press car body shell to
shape; most actual cutting elements on machine tools.

tr A governing element is an element occupying a longer time than that of

any other element which is being performed concurrently.
Examples: turn diameter on a lathe, while gauging from time to time; boil
kettle of water, while setting out teapot and cups; develop photographic
negative, while agitating the solution occasionally.

D A foreign element is an element observed during a study which, after

analysis, is not found to be a necessary part ofthejob.
Examples: in furniture manufacture, sanding the edge of a board before
planing has been completed; degreasing a part that has still to be machined
228 further.
 -ECTING AND TIMING THE JOB

It will be clear from the definitions given above that a repetitive element
may also be a constant element, or a variable one. Similarly, a constant element may
also be repetitive or occasional; an occasional element may be constant or variable,
and so on, for the categories are not mutually exclusive.

7. Deciding on the elements

There are some general rules concerning the way in which a job should be
broken down into elements. They include the following:

tr Elements should be easily identifiable, with definite beginnings and endings

so that, once established, they can be repeatedly recognised. These begin-
nings and endings can often be recognised by a sound (e.g. the stopping of a
machine, unlocking a catch of a jig, putting down a tool) or by a change of
direction of hand or arm. They are known as the "break points" and should
be clearly described on the study sheet. A break point is thus the instant at
which one element in a work cycle ends and another begins.
tr Elements should be as short as can be conveniently timed by a trained
observer. Opinion differs on the smallest practical unit that can be timed
with a stopwatch, but it is generally considered to be about 0.04 min (2.4
sec).tFor less highly trained observers it may be 0.07 to 0.10 min. Very
short elements should, if possible, be next to longer elements lor accurate
timing and recording. Long manual elements should be rated about every
0.33 min (20 sec). (Rating is described and discussed in the next chapter.)
tr As far as possible, elements-particularly manual ones-should be chosen
so that they represent naturally unified and recognisably distinct segments
of the operation. For example, consider the action of reaching for a wrench,
moving it to the work and positioning it to tighten a nut. It is possible to
identify the actions of reaching, grasping, moving to the workpiece, shifting
the wrench in the hand to the position giving the best grip for turning it, and
positioning. The worker will probably perform all these as one natural set of
motions rather than as a series of independent acts. It is better to treat the
group as a whole, defining the element as "get wrench" or ooget and position
wrench" and to time the whole set of motions which make up the group,
than to select a break point at, say, the instant the fingers first touch the
wrench, which would result in the natural group of motions being divided
between two elements.
tr Manual elements should be separated from machine elements. Machine
time with automatic feeds or fixed speeds can be calculated and used as a
check on the stop-watch data. Hand time is normally completely within the
control of the operative. This separation is especially important if standard
times are being compiled.

rProfessor Barnes-says "0.03 to 0.04 minutes". See Ralph M. Barnes: Motion and time study:
pp.221ff,
Design and measurement of work (New York and London, John Wiley, 5th ed., 1966), 229
 TIME STUDY: SELECTING AND TIMING THE JOB

tr Constant elements should be separated from variable elements.

D Elements which do not occur in every cycle (i.e. occasional and foreign
elements) should be timed separately from those that do.

The necessity for a fine breakdown of elements depends largely on the type
of manufacturing, the nature of the operation and the results desired. Assembly opera-
tions in the light electrical and radio industries, for example, generally have short cycle
operations with very short elements.
The importance of the proper selection, definition and description of ele-
ments must again be emphasised. The amount of detail in the description will depend
on a number of factors, for instance-

tr Small batch jobs which occur infrequently require less detailed element
descriptions than long-running, high-output lines.
! Movement from place to place generally requires less description than hand
and arm movements.

Elements should be checked through a number of cycles and written down

before timing begins.
Examples of element descriptions and of various types of element are
shown in figures 95 and 97.

8. Sample size
Much of what we said in Chapter 14 on sampling, confidence levels and the
application of random tables applies here also. In this case, however, we are not con-
cerned with a proportion but with finding out the value of the representative average
for each element. Our problem, therefore, is to determine the sample size or number of
readings that must be made for each element, given a predetermined confidence level
and accuracy margin.
Here again, we can apply a statistical method or a conventional method.
For the statistical method, we have first to take a number of preliminary
readings (n'). We then apply the following equationr for the 95.45 confidence level
and a margin of error of + 5 per cent:

40 G
|,7, b'z -(Lxr l'z
n:
where
n : sample size we wish to determine
n' : number of readings taken in the preliminary study
I : sum ofvalues
x : value ofthe readings.

rThe explanation ofthe derivation ofthis formula falls outside the scope ofthis book. See Raymond
Mayer: Production and operations management (New York and London, McGraw-Hill, 3rd ed., 1975), pp. 516-
230 5 17.
 An example will make the point clear. Let us suppose that we take five
readings for a given element, and hnd that the value of the elapsed time in 1/100ths of
a minute is 7, 6, 7 , 7 , 6. We can then calculate the squares and the sum of the squares
of these numbers-
xxz
749
636
749
749
636
Ix:33 Ex2:219
nt :5 readings.
By substituting these values in the above formula, we obtain the value of n:

.- 140 v s(2le) - (33)'

(33),
tx )': 10.3 or 11 readings.

Since the number of preliminary readings n' that we took is less than the re-
quired sample size of I l, the sample size must be increased. However, we cannot
simply say that six more observations are needed. When we add the values obtained
from these six additional observations, the values of x and x2 will change, and this
may affect the value of n. Consequently it may be found either that a still larger sam-
ple is required, or that the sample taken was in fact adequate or more than adequate.
If we choose a different confidence level and accuracy margin, the formula
changes as well. Normally, however, we choose either the 95 or the 95.45 confidence
level.
The statistical method of determining the sample size is valid to the extent
that the assumptions made in deriving the formula are valid-in other words, that the
observed variations in the readings are due to mere chance and are not made inten-
tionally by the operative. The statistical method can be cumbersome, since a given
work cycle is composed of several elements. As the sample size will vary with the
readings for each element, we can arrive at different sample sizes for each element
within a given cycle, unless of course the elements have more or less the same
average. As a result, we may have to calculate the sample size, in the case of cumu-
lative timing, by basing it on the element that will call for the largest sample size.
Some authors, and companies such as General Electric, have therefore
adopted a conventional guide for the number of cycles to be timed, based on the total
number of minutes per cycle (see table l5).
It is also important that the readings be continued over a number of cycles
in order to ensure that occasional elements (such as handling boxes of finished parts,
periodical cleaning of machines or sharpening of tools) can be observed several times.
In conducting the study the table of random numbers (see Chapter 14) may
be used to determine the times at which the readings are to be taken. 231
 TIME STI.JDY: SELECTING AND TIMING THE JOB

Table 15. Number of recommended cycles for time study

Minutes per cycle To To To To To To To To fo To Over

0.r0 0.25 0.50 0.75 1.0 2.0 5.0 t0.0 20.0 40.0 40

Number of cycles
recommended 200 100 60 40 30 20 15 l0 8 5 3

Source: A. E. Shaw: "stopwatch time study". in H. B. Mayntrd (ed.): lndustrial engineering handbook, op. cit. Reproduced by kind permission
of the McGraw-Hill B@k Company.

9. Timing each element: stop-watch procedure

When the elements have been selected and written down, timing can start.
There are two principal methods of timing with the stop-watch:

tl Cumulative timing;
D Flyback timing.

In cumulative timing the watch runs continuously throughout the study. It

is started the beginning of the first element of the first cycle to be timed and is not
at
stopped until the whole study is completed. At the end of each element the watch
reading is recorded. The individual element times are obtained by successive subtrac-
tions after the study is completed. The purpose of this procedure is to ensure that all
the time during which the job is observed is recorded in the study.
In flyback timing the hands of the stopwatch are returned to zero at the end
of each element and are allowed to start immediately, the time for each element being
obtained directly. The mechanism of the watch is never stopped and the hand im-
mediately starts to record the time of the next element.
In all time studies it is usual to take an independent check of the over-all
time of the study, using either a wrist-watch or the clock in the study office. This also
serves the purpose of noting the time of day at which the study was taken, which may
be important if a retiming is asked for. For example, the cycle time of an operative on
a repititive job may be shorter in the first hour or two of the morning, when he is
fresh, than late in the afternoon, when he is tired.
In the case of flyback timing, the studyman walks to the clock; at an exact
minute, preferably at the next major division such as the hour or one of the five-
minute points, he sets his stop-watch running, noting the exact time in the "time on"
space on the form. He returns to the workplace where he is going to carry out the time
study with the watch running and allows it to do so continuously until he is ready to
start timing. At the beginning of the first element of the first work cycle, he snaps back
the hand, noting, as the first entry on the body of his study sheet, the time that has
elapsed. At the end of the study, the hand is snapped back to zero on completion of
the last element of the last cycle and thereafter allowed to run continuously until he
can again reach the clock and note the time of finishing, when the watch is finally
stopped. The final clock time is entered in the "time off' space on the form. The two
232 times recorded before and after the study are known as "check times". The clock
 TIME STUDY: SELECTING AND TIMING THE JOB

reading at the beginning ofthe study is subtracted from the clock reading at the end
of the study to give the "elapsed time"o which is entered on the form.
The sum of the times of all the elements and other activities noted in the
study plus ineffective time plus the check times is known as the'orecorded time" and is
also noted. It should in theory agree with the elapsed time, but in practice there is
usually a small difference owing to the cumulative loss of very small fractions of time
at the return of the hand to zero and, possibly, bad reading or missed elements. In cer-
tain firms it is the practice to discard any study in which the elapsed time differs from
the recorded time by more than t 2 per cent.
When the same practice is followed using cumulative timing, the elapsed
time and recorded time should be identical since the stop-watch is only read and not
snapped back.
Cumulative timing has the advantage that, even if an element is missed or
some occasional activity not recorded, this will have no effect on the over-all time. It is
strongly favoured by many trade unions, especially in the United States, since it is
regarded by them as more accurate than flyback timing and gives no opportunity for
altering times in favour of the management by omitting elements or other activities. Its
disadvantage is, of course, the amount of subtraction which has to be done to arrive at
individual element times, which greatly increases the time taken in working up the
study afterwards.
Flyback timing is still widely used. In competent hands it is almost as
accurate as cumulative timing. Mundel quotes some comparative tests of the two
methods carried out by Lazarus at the Purdue University Motion and Time Study
Laboratory with a number of experienced time study observers, in which the average
error in reading the watch using the cumulative method was + 0.000097 min per
reading and using the flyback method was
-0.00082 min per reading.r Errors of this
order are not large enough to influence subsequent calculations. It should be noted,
however, that these very small average errors were made by experienced observers.
There is reason to suppose that people being trained in the use of the stop-watch attain
a fair degree of accuracy more quickly when using the cumulative method than when
using the flyback method.
The experience of ILO missions in training in and applying time study has
in fact shown that, generally speaking, cumulative timing should be taught and used,
for the following reasons:
(1) Experience suggests that trainees achieve reasonable accuracy in the use of the
stop-watch more quickly if they use the cumulative method.
(2) lt does not matter if element times are occasionally missed by inexperienced
observers; the over-all time of the study will not be affected. Foreign elements and
interruptions are automatically included since the watch is never stopped.
(3) In assessing the working pace of the operative ('rating"), it is less easy to fall into
the temptation to adjust the rating to the time taken by the element than with the
flyback method, since only watch readings and not actual times are recorded.

I L. P. Lazarus: "The nature of stop-watch time study etors",'tn Advanced Management,May 1950,
pp. 15-16. 233
 TIME STUDY: SELECTING AND.

(4) Workers and their representatives are likely to have greater faith in the fairness of
time studies as a basis for incentive plans if they can see that no tirne could have
been omitted. The introduction of time study into an undertaking or an industry
may be made easier.

In the flyback method, errors in reading the watch may be added to the
slight delay which occurs when the hand is snapped back to zero. The percentage
error becomes greater for short elements. Cumulative timing is therefore likely to be
more accurate for short-element short-cycle work, while flyback timing can be more
safely used in jobs with long elements and cycles, since the error becomes too small to
matter. The question of the confidence of the workers is important as well.
There is a third method of timing which is employed for short-element
short-cycle work, and which may indeed be the only way of getting accurate times
with a stop-watch, for elements which are so very short that there is not enough time
for the studyman to read his watch and make a recording on his study sheet. In this
situation the method used is that known as differential timing. With differential timing,
elements are timed in groups, first including and then excluding each small element,
the time for each element being obtained subsequently by subtraction. For example, if
the job consists of seven short elements, the studyman may time numbers I to 3, and
4 to 7 for the first few cycles, recording only these two readings per cycle. He would
then time I to 4 and 5 to 7 for a few cycles; and so on. If differential timing is applied
in this fashion, either the cumulative or the flyback method of watch manipulation
may be used.
We have now discussed all the preliminaries to making a time study, from
the selection of the job, through the recording of all relevant data, the breakdown of
the job into elements and the examination of the methods employed, to the recording
of the actual element times. In the next chapter we shall discuss the means of modify-
ing these observed times to take into account variations in rates of working.

234
 Cha
Time study: Rating

In section 3 of the previous chapter, the making of a time study was broken
down into eight steps or stages, the first four of which were discussed in that chapter.
We now come to the ffth step, namely ooassessing the effective speed of working of the
operative relative to the observer's concept of the rate corresponding to standard
rating".
The treatment of rating which follows has beenselected because experience
in the use of this book for training purposes by ILO management and productivity
missions suggests that this approach to the subject is best suited to the conditions in
most of the countries for which the book is primarily intended.
Rating and "allowances" (dealt with in the next chapter) are the two most
controversial aspects of time study. Most time studies in industry are used to deter-
mine standard times for setting workloads and as a basis for incentive plans. The
procedures employed have a bearing on the earnings of the workers as well as on the
productivity and, possibly, the profits of the enterprise. Time study is not an exact
science, although much research has been and continues to be undertaken to attempt
to establish a scientific basis for it. Rating (the assessment of a worker's rate of work-
ing) and the allowances to be given for recovery from fatigue and other purposes are
still, however, largely matters of judgement and therefore of bargaining between
management and labour.
Various methods of assessing the rate of working, each of which has its
good and bad points, have been developed. The procedures set out in this chapter
represent sound current practice and, properly applied, should be acceptable to
management and workers alike, particularly when used to determine standards for
medium-batch production, which is the most common type in industry all over the
world outside the United States and a few large or specialised undertakings elsewhere.
They will certainly provide the reader with a sound basic system which will serve him
well for most general applications, and one which can later be refined if the particular
nature of certain special operations requires a modification of the system, so as to rate
something other than effective speed.

1. The qualified worker

It
has already been said that time studies should be made, as far as possible,
on a number of qualified workers; and that very fast or very slow workers should be 235
 TIME STUDY: RATING

avoided, at least while making the first few studies of an operation. What is a "quali-
fied worker"?
Different jobs require dilferent human abilities. For example, some demand
mental alertness, concentration, visual acuity; others, physical strength; most, some
acquired skill or special knowledge. Not all workers will have the abilities required to
perform a particular job, though if the management makes use of sound selection
procedures and job training programmes, it should normally be possible to arrange
that most of the workers engaged on it have the attributes needed to fit them for the
task. The definition of a qualified worker given in the previous chapter is repeated
here-

The acquisition of skill is a complicated process. It has been observedr that

among the attributes which differentiate the experienced worker from the inexperi-
enced are the following. The experienced worker-

achieves smooth and consistent movements;

acquires rhythm;
responds more rapidly to signals;
anticipates diffrculties and is more ready to overcome them;
carries out the task without giving the appearance of conscious attention,
and is therefore more relaxed.

It may take a good deal of time for a worker to become fully skilled in the
performance of a job. In one study (see figure 64) it was noted that it was only after
some 8,000 cycles of practice that the times taken by workers began to approach a
constant figure-which was itself half the time they took when they first essayed the
operation. Thus time standards set on the basis of the rate of working of inexperienced
workers could turn out to be quite badly wrong, if the job is one with a long learning
period. Some jobs, of course, can be learned very quickly.
It would be ideal if the time study man could be sure that, whatever job he
selected for study, he would find only properly qualified workers performing it. In
practice this is too much to hope for. It may indeed be that none of the workers
engaged on the task can really be said to be completely qualified to carry it out,
though it may be possible to alter this in time, by training; or that, though some of the

236 t W. D. Seymour: Industrial trainingfor manual operations (London, Pitman, 1966).

 TIME STUDY: RATING

workers are qualified, these are so few in number that they cannot be considered to be
average or representative of the group. A representative worker is defined as one
whose skill and performance is the ayera5e of a group under consideration. He is not
necessarily a qualified worker.
If the working group is made up wholly or mainly of qualified workers,
there will be one-or perhaps several-of these qualified workers who can be con-
sidered as representative workers also. The concept of a standard time is, at root, that
it is a time for a job or operation that should normally be attainable by the average
qualified worker, working in his ordinary fashion, provided that he is suffrciently
motivated to want to get on with the job. In theory, therefore, the time study man
should be looking for the average qualified worker to study. In practice, this is not as
easy as it might seem. It is worth looking more closely into what ooaverage" might
mean in this context.

2. The "average" worker

The truly average worker is no more than an idea. A completely average
worker does not exist, any more than an "average family" or an "average man" exists.
They are the inventions of statisticians. We are all individuals: no two of us are ex-
actly alike. Nevertheless, among a large number of people from, for instance, the same
country or area) variations in measurable characteristics such as height and weight
tend to form a pattern which, when represented graphically, is called the "normal dis-
tribution curve". To take one characteristic, height: in many western European
countries the average height for a man is about 5 ft. 8 n. (L72 cm). If a crowd is a
western European crowd, a large number of the men in it will be between 5 ft. 7 in.
and 5ft. 9 in. tall (17G175 im). The number of men of heights greater or smaller than
this will become fewer and fewer as those heights approach the extremes of tallness
and shortness.
The case as regards the performance of operatives is exactly the same. This
can be shown very convenienfly in a diagram (figure 82). If 500 qualified workers in a
given factory were to do the same operation by the same methods and under the same
conditions, the whole operation being within the control of the worker himself, the
times taken to perform the operation would be distributed in the manner shown in the
figure. To simplify the figure, the times have been divided into groups at intervals of
four seconds. It will be seen that the workers fall into the groups shown in table 16.
If the time groups are examined, it will be seen that 32.4 per cent of the
times are less than 46 seconds and 34.8 per cent of the times are greater than 50
seconds. The largest single group of times (32.8 per cent) lies between 46 and 50
seconds. We should therefore be justified in saying that for this group of 500 workers
the average time taken to perform this operation was between 46 and 50 seconds (say,
48 seconds). We could call 48 seconds the time taken by the average qualified worker
to do this job under these conditions. The time might not hold good for any other fac-
tory. Factories which are well run, where working conditions and pay are good, tend
to attract and keep the best workers, so that in a better run factory the average
worker's time might be less (say, 44 seconds), while in a poorly run factory with less
able workers it might be more (say, 52 seconds). 237
 TIME STUDY: RATING

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 IIME STUDY: RATING

Table 16. Specimen performance distribution

Time group (sec) Number ofworkers (out of 500) Percentage of total workers

30-34 4 0.8
34-38 l6 3.2
32.4
38-42 38 1.6
42-46 104 20.8
46-50 164 32.8 32.8
50-54 113 22.6
54-58 48 9.6
34.8
58-62 l1 2.2
62-66 2 0.4

100.0 100.0

If a curve is drawn to fit this distribution it will be found to assume the

oonormal
shape of the curve in the flrgure. This is known as the distribution curve". In
general, the larger the sample the more the curve will tend to be symmetrical about the
peak value, but this can be altered if special conditions are introduced. For example, if
the slower workers were to be transferred to otlrer work, the right-hand side of the
curve of performances of the group would probably become foreshortened, for there
would be fewer workers returning the very long times.

3. Standard rating and standard performance

In Chapter 13 it was said that the principal use of work measurement (and
hence of time study) is to set time standards which can be used for a number of dif-
ferent purposes (including programme planning, estimating, and as a basis for incen-
tives) for the various jobs carried out in the undertaking.t Obviously, if those time
standards are to be of any value at all, their achievement must be within the capacity
of the majority of workers in the enterprise. It would be no use setting standards so
high that only the best could attain them, since programmes or estimates based on
them would never be fulfilled. Equally, to set standards well within the achievement of
the slowest workers would not be conducive to efficiency.
How does the work study man obtain such a fair time from time studies?
We have already said that, as far as possible, studies should be taken on
qualified workers. If it were possible to obtain the times taken by 500 qualified
operatives for a single operation and plot them in the manner shown in figure 82, a
reliable average time would be obtained. Unfortunately, this is hardly ever possible. It
is not always possible to time a job on an average qualified worker; moreover, even if
it were, people do not work consistently from day to day or even from minute to
minute. The work study man has to have some means of assessing the rate of working
of the operative he is observing and of relating it to standard pace. This process is
known as rating.

tFor details olvarious well known types olincentive plans, seelLO: Payment by results, Studies and
reports, New series, No. 27 (Geneva, l4th impr., 1977). 239
 TIME STUDY: RATING

By definition, rating is a comparison of the rate of working observed by the

work study man with a picture of some standard level which he is holding in his mind.
This standard level is the average rate at which qualified workers will naturally work
at a job, when using the correct method and when motivated to apply themselves to
their work. This rate of working corresponds to what is termed the standard rating,
and is denoted by 100 on the rating scale recommended to readers of this book (see
section 7 below). If the standard pace is maintained and the appropriate relaxation is
taken, a worker will achieve standard performance over the working day or shift.

The rate of working most generally accepted in the United Kingdom and
the United States as corresponding to the standard rating is equivalent to the speed of
motion of the limbs of a man of average physique walking without a load in a straight
line on level ground at a speed of 4 miles an hour (6.4 kilometres per hour). This is a
brisk, business-like rate of walking, which a man of the right physique and well ac-
customed to walking might be expected to maintain, provided that he took ap-
propriate rest pauses every so often. This pace has been selected, as a result of long
experience, as providing a suitable benchmark to correspond to a rate of working
which would enable the average qualified worker who is prepared to apply himself to
his task to earn a fair bonus by working at that rate, without there being any risk of
imposing on him any undue strain which would affect his health, even over a long
period of time. (As a matter of interest, a man walking at 4 miles an hour (6.4 km/h)
appears to be moving with some purpose or destination in mind: he is not sauntering,
but on the other hand he is not hurrying. Men hurrying, to catch a train for instance,
tThe definition given in the B.S. Glossary, op. cit., concludes with the words "standard rating",
rather than "standard pace", as used here. It is considered that the word "pace" more exactly conveys the sense
of a rate of working than "rating", which has connotations implying a factor, or ratio, which do not help clarity
240 at this point in the explanation,
 TIME STUDY: RATING

often walk at a considerably faster pace before breaking out into a trot or a run, but it
is a pace which they would not wish to keep up for very long.)
It should be noted, however, that the "standard pace" applies to Europeans
and North Americans working in temperate conditions; it may not be a proper pace to
consider standard in other parts of the world. In general, however, given workers of
proper physique, adequately nourished, fully trained and suitably motivated, there
seems little evidence to suggest that different standards for rates of working are
needed in different localities, though the periods of time over which workers may be
expected to average the standard pace will vary very widely with the environmental
conditions. At the very least, the standard rate as described above provides a
theoretical datum line with which comparisons of performance in different parts of the
world could be made in order to determine whether any adjustment may be necessary.
Another accepted example of working at the standard rate is dealing a pack of 52
playing cards in 0.375 minutes.
Standard performance on the part of the average qualified worker (that is,
one with suffrcient intelligence and physique, adequately trained and experienced in
the job he is doing) will probably show as such only over a period of several hours.
Anyone doing manual work will generally carry out the motions directly concerned
with his work at his own natural working rate, which may not be exactly the standard
rate, since some men work faster than others. There will of course be different stan-
dard paces (or speeds of movement) for different activities, according to the complex-
ity or arduousness of the element making up the activity (among other things), so that
working at the standard rate will not always mean moving the hands or limbs at the
same speed. And in any event, it is not uncommon for workers to work faster at some
periods of the day than at others, so that the standard performance is rarely achieved
as the result of working, without any deviation, at the standard rate throughout the
working periods of the shift, but rather as the cumulative outcome of periods of work
at varying paces.
When time standards are used as a basis for payment by results, many
union-management agreements stipulate that the time standards should be such that a
representative or average qualified worker on incentive pay can earn 20-35 per cent
above his time rate by achieving the standard performance. If the worker has no
target to aim at and no incentive to make him desire a higher output, he will (apart
from any time he may waste consciously) tolerate the intrusion of small pieces of
ineffective time, often seconds or fractions of seconds between and within elements of
work. In this way he may easily reduce his performance over an hour or so to a level
much below that of the standard performance. If, however, he is given enough incen-
tive to make him want to increase his output, he will get rid of these small periods of
ineffective time, and the gaps between his productive movements will narrow. This
may also alter the pattern of his movements.l The effect of the elimination of these
small periods of ineffective time under the influence of an incentive can be illus-
trated diagrammatically (see figure 83).

rResearch carried out under the late Professor T. U. Matthew at the University ol Birmingham
(United Kingdom) tended to confirmthis. 241
 TIME STUDY: RATING

Figure 83. Effect of ineffective time on performance

Worker

l5 min 30 min 45 min

Work done in one hour by A

Work done in one hour by B

Productive time lneftective time

!

What happens may be seen in the case of a man working a lathe who has to
gauge his workpiece from time to time. His gauge is laid on the tool locker beside him.
If he has no particular reason to hurry, he may turn his whole body round every time
he wishes to pick up the gauge, turn back to the lathe, gauge the workpiece and turn
again to put the gauge down, each of these movements being carried out at his natural
pace. As soon as he has reason to speed up his rate of working, instead of turning his
whole body he will merely stretch out his arm, perhaps glancing round to check the
position of the gauge on the locker, pick up the gauge, gauge the workpiece and
replace the gauge on the locker with a movement of his arm, without bothering to
look. In neither case would there be a deliberate stopping of work, but in the second
some movements-ineffective from the point of view of furthering the
operation-would have been eliminated.
The effect of putting a whole shop or factory (such as the 500 workers in
figure 82) on an incentive is shown in figure 84.
Offering an incentive in the form of payment in proportion to output will
not make the unskilled or slow worker as fast or as skilled as the skilled or naturally
fast worker; but if everyone in the shop is put on a well designed incentive plan, other
conditions remaining the same, the result will be that everyone will tend to work more
consistently. The short periods of ineffective time discussed above will disappear, and
everyone's average time for the job will be reduced. (This is an over-simplification but
true enough for purposes of illustration.) The normal distribution curve shown in
figure 82 will move to the left while retaiiling approximately the same shape. This is
quite clearly shown in figure 84, where the peak of the curve (the average time) now
comes at 36 seconds instead of 48-a reduction of 25 per cent.
It
should be added that, although the standard rate of working is that at
242 which the average qualified worker will naturally perform his movements when
 TIME STUDY: RATING

Figure 84. Effect of a payment-by-results incentive on the time taken to perform an operation
a_

v,
e
t{
to
i
o
ci
e

srcofr'Ds 36 48
Workcrs on Workers not
incentive on incentive

motivated to apply himself to his task, it is of course quite possible and indeed normal
for him to exceed this rate of working if he wishes to do so, just as a man can walk
faster than 4 miles an hour if he wants to. Men will be observed to be working,
sometimes faster, sometimes slower than the standard rate, during short periods. Stan-
dard performance is achieved by working over the shift at paces which average the
standard rate.

4. Comparing the observed rate of working with the standard

How is it possible accurately to compare the observed rate of working with
the theoretical standard? By long practice.
Let us return once more to our man walking. Most people, if asked, would
be able to judge the rate at which a man is walking. They would start by classifying
rates of walking as slow, average or fast. With a little practice they would be able to
say: "About 3 miles an hour, about 4 miles an hour, or about 5 miles an hour" (or of
course the equivalent rates in kilometres if they are more used to kilometres). If,
however, a reasonably intelligent person were to spend all his time watching men
walking at different speeds, he would soon reach the point where he could say: "That
man is walking at 2Yz miles an hour and this one at 4Yq miles an hour", and he would
be right, within close limits. In order to achieve such accuracy, however, he would
need to have in his mind some particular rate with which to compare those which he
sees.

That is exactly what the work study man does in rating; but, since the
operations which he has to observe are far more complex than the simple one of walk-
ing without load, his training takes very much longer. Judgement of walking pace
is only used for training work study men in the flrrst stages; it bears very little
resemblance to most of the jobs that have to be rated. It has been found better to use
films or live demonstrations of industrial operations. 243
 Confidence in the accuracy of one's rating can be acquired only through
long experience and practice on many types of operation-and confidence is essential
to a work study man. It may be necessary for him to back his judgement in arguments
with the management, foremen or workers' representatives; unless he can do so with
assurance, the confidence of all parties in his ability will quickly disappear, and he
might as well give up practising time study. This is one of the reasons why trainees
may attempt method study after a comparatively short training but should on no
account try to set time standards-except under expert guidance-without long
practice, especially if the standards are to be used for incentive payments.

5. What is rated?

The purpose of rating is to determine, from the time actually taken by the
operative being observed, the standard time which can be maintained by the average
qualified worker and which can be used as a realistic basis for planning, control and
incentive schemes. What the studyman is concerned with is therefore the speed with
which the operative carries out the work, in relation to the studyman's concept of a
normal speed. In fact, speed of working as recorded by the time taken to carry out the
elements of the operation is the only thing which can be measured with a stop-watch.
Most authorities on time study agree on this point.
Speed of what? Certainly not merely speed for movement, because an
unskilled operative may move extremely fast and yet take longer to perform an opera-
tion than a skilled operative who appears to be working quite slowly. The unskilled
operative puts in a lot of unnecessary movements which the experienced operative has
long since eliminated. The only thing that counts is the effective speed of the opera-
tion. Judgement of effective speed can only be acquired through experience and
knowledge of the operations being observed. It is very easy for an inexperienced
studyman either to be fooled by a large number of rapid movements into believing that
an operative is working at a high rate or to underestimate the rate of working of the
skilled operative whose apparently slow movements are very economical of motion.
A constant source of discussion in time study is the rating of effort. Should
effort be rated, and if so, how? The problem arises as soon as it becomes necessary to
study jobs other than very light work where little muscular effort is required. Effort is
very difficult to rate. The result of exerting effort is usually only seen in the speed.
The amount of effort which has to be exerted and the difficulty encountered
by the operative is a matter for the studyman to judge in the light of his experience
with the type of job. For example, if an operative has to lift a heavy mould from the
filling table, carry it across the shop and put it on the ground near the ladle, only
experience will tell the observer whether the speed at which he is doing it is normal,
above normal or sub-normal. Anyone who had never studied operations involving the
carrying of heavy weights would have great difficulty in making an assessment the
first time he saw such an operation.
Operations involving mental activities (udgement of finish, for example, in
inspection of work) are most difficult to assess. Experience of the type of work is re-
244 quired before satisfactory assessments can be made. Inexperienced studymen can be
 TIME STUDY: RATING

made to look very foolish in such cases, and moreover can be unjust to above-average
and conscientious workers.
In any job the speed of accomplishment must be related to an idea of a nor-
mal speed for the same type of work. This is an important reason for doing a proper
method study on a job before attempting to set a time standard. It enables the
studyman to gain a clear understanding of the nature of the work and often enables
him to eliminate excessive effort or judgement and so bring his rating process nearer
to a simple assessment of speed.
In the next section some of the factors affecting the rate of working of the
operative will be discussed.

6. Factors affecting the rate of working

Variations in actual times for a particular element may be due to factors
outside or within the control of the worker. Those outside his control may be-

tr Variations in the quality or other characteristics of the material used,

although they may be within the prescribed tolerance limits.
tr Changes in the operating efficiency of tools or equipment within their useful
life.
tr Minor and unavoidable changes in methods or conditions of operation.
tl Variations in the mental attention necessary for the performance of certain
of the elements.
tr Changes in climatic and other surrounding conditions such as light,
temperature, etc.

These can generally be accounted for by taking a sufficient number of

studies to ensure that a representative sample of times is obtained.
Factors within his control may be-
tr Acceptable variations in the quality of the product.
D Variations due to his ability.
tr Variations due to his attitude of mind, especially his attitude to the organisa-
tion for which he works.
The factors within the worker's control can affect the times of similarly
described elements of work by affecting-
tr The pattern of his movements.
tr His working pace.
tr Both, in varying proportions.

The studyman must therefore have a clear idea of the pattern of movement
which a qualified worker should follow, and of how this pattern may be varied to meet
the range of conditions which that worker may encounter. Highly repetitive work 245
 TIME STUDY: BATING

likely to run for long periods should have been studied in detail through the use of
refined method study techniques, and the worker should have been suitably trained in
the patterns of movement appropriate to each element.
The optimum pace at which the worker will work depends on-
tr The physical effort demanded by the work.
tr The care required on the part of the worker.
tr His training and experience.

Greater physical effort will tend to slow up the pace. The ease with which
the effort is made will also influence the pace. For example, an effort made in condi-
tions where the operative cannot exert his strength in the most convenient way will be
made much more slowly than one of the same magnitude in which he can exert his
strength in a straightforward manner (for instance, pushing a car with one hand
through the window on the steering wheel, as opposed to pushing it from behind).
Care must be taken to distinguish between slowing up due to effort and slowing up
due to fatigue.

When the element is one in which the worker is heavily loaded, so that he
has to exert considerable physical effort throughout, it is unlikely that he will perform
it at anything other than his natural best pace. In such circumstances rating may be
superfluous: it may be sufficient to determine the average of the actual times taken
during an adequate number of observations. This was very strikingly shown during an
ILO study of manual earth-moving operations carried out in India. The workers-
men, women and youths-carried loads of earth up to 84 lb (38 kg) in weight
on their heads, in wicker baskets. A man with 84 lb on his head does not dawdle.
He is anxious to get to the end of his walk and get rid of the load, and so performs
the task at the best rate that he can naturally achieve. In doing so he shortens his
stride, taking very short paces very quickly so that it looks almost as though he is go-
ing to break out into a trot at any moment. In point of fact, the stop-watch showed
that the time taken for the loaded walk was a good deal longer than that needed for
the apparently more leisurely return unloaded, so that the studyman without ex-
perience of the effort involved in the operation could very easily be led into making
false ratings. In fact, for the loaded walk ratings were not necessary, except when con-
tingencies occurred. Similar heavily loaded elements occur in factories, as in carrying
sacks, picking them up, or throwing them down on to stacks. These operations are
most likely to be carried out at the best natural pace which the worker can manage.
An increased need for care in carrying out an element will reduce the pace.
An example is placing a peg with parallel sides in a hole, which requires more care
than if the peg is tapered.
Fumbling and hesitation on the part of the worker are factors which the
studyman must learn to recognise and cope with. A worker's natural skill and dex-
terity combined with training and experience will reduce the introduction of minor
method variations (fumbling), and also the foreign element "consider" (hesitation).
Very slight deviations from the standard method can be taken into account by assign-
ing a lower rating, but fumbling and hesitation usually signal a need for further train-
246 ing.
 SrUDY: RATTNG

The studyman should be careful not to rate too highly *n"nl"

tr The worker is worried or looks hurried.
tr The worker is obviously being over-careful.
tl Thejob looks diflicult to the studyman.
tr The studyman himself is working very fast, as when recording a short-
element study.

Conversely, there is a danger of rating too low when-

D The worker makes the job look easy.
tr The worker is using smooth, rhythmic movements.
tr The worker does not pause to think when the studyman expects him to do
so.
n The worker is performing heavy manual work.
tr The studyman himself is tired.

The studyman must take such factors into account. Rating is very much
easier if a good method study has been made first, in which the activities calling for
special skill or effort have been reduced to a minimum. The more the method has been
simplihed, the less the element of skill to be assessed and the more rating becomes a
matter of simply judging pace.

7. Scales of rating
In order that a comparison between the observed rate of working and the
standard rate may be made effectively, it is necessary to have a numerical scale
against which to make the assessment. The rating can then be used as a factor by
which the observed time can be multiplied to give the basic time, which is the time it
would take the qualified worker, motivated to apply himself, to carry out the element
at standard rating.
There are several scales of rating in use, the most common of which are
those designated the 100-133 scale, the 60-80, the 75-100, and the British Standard
scale used in this book (essentially a restatement of the 75-100 scale) which is the
0-100 scale.
Table 17 shows examples of various rates of working on the scales men-
tioned.
In the 100-133, 6G80 and 75-100 scales, the lower figure in each instance
was defined as the rate of working of an operative on time rates of pay; and the
higher, in each case one-third higher, corresponded to the rate of working we have
called the standard rate, that of a qualified worker who is suitably motivated to apply
himself to his work, as for instance by an incentive scheme. The underlying assump-
tion was that workers on incentive perform, on.average, about one-third more effec-
tively than those who are not. This assumption has been well substantiated by prac-
tical experience over many years, but it is largely irrelwant in the construction of a
rating scale. All the scales are linear. There is therefore no need to denote an 247
 TIME STUDY: RATING

Table 17. Examples of various rates of working on the principal rating scales

Description Comparable
walking speed'
to0- 133 0- r00
Statrdard
(mi/h)

000 0 No activity.

40 50 61 50 Very slow; clumsy, fumbling move- 3.2

ments; operative appears half
asleep, with no interest in the job.

60 75 100 Steady, deliberate, unhurried per- 4.8

formance, as of a worker not on
piecework but under proper super-
vision; looks slow, but time is not
being intentionally wasted while
under observation.

r33 100 Brisk, business-like performance, as

(Standard of an average qualified worker on
Rating) piecework; necessary standard of
quality and accuracy achieved with
confidence.

100 125 167 125 Very fast; operative exhibits a high 8.0
degree of assurance, dexterity and
co-ordination of movement, well
above that of an average trained
worker.

r20 150 200 Exceptionally fast; requires intense 9.6

effort and concentration, and is un-
likely to be kept up for long periods;
a "virtuoso" performance achieved
only by a few outstanding workers.

'Assuming an operative of average heighl and physique, unladen, walking in a straight line on a smmth level surface without obstructions.
Soarce.' Freely adapted from a table issued by the Enginering and Allied Employers (West of England) Association, Department of Work Study.

intermediate point between zero and the figure chosen to represent the standard rating
as we have defined it. Whichever scale is used, the final time standards derived should
be equivalent, for the work itself does not change even though different scales are used
to assess the rate at which it is being carried out.
The newer 0-100 scale has, however, certain important advantages which
have led to its adoption as the British Standard. It is commended to readers of this
book and is used in all the examples which follow. In the 0-100 scale, 0 represents
zero activity and 100 the normal rate of working of the motivated qualified
worker-that is, the standard rate.

8. How the rating factor is used

The figure 100 represents standard performance. If the studyman decides
248 that the operation he is observing is being performed with less effective speed than his
 TIME STUDY: RATING

concept of standard, he will use a factor of less than 100, say 90 or 75 or whatever he
considers represents a proper assessment. If, on the other hand, he decides that the
effective rate of working is above standard, he gives it a factor greater than 100-
say, I 10, I 15 or 120.
It is the usual practice to round off ratings to the nearest multiple of five on
the scale; that is to say, if the rate is judged to be 13 per cent above standard, it would
be put down at 1 15. During the first weeks of their training, studymen are unlikely to
be able to rate more closely than the nearest ten.
If the studyman's ratings were always impeccable, then however many
times he rates and times an element the result should be that-

Observed Time x Rating: A Constant

provided that the element is of the type described as a constant element in section 6 of
the previous chapter, and that it is always performed in the same way.
An example, expressed numerically, might read as follows:

Observed time
Cycle (decimal minutes) Rating Conslant
I O.2O x 100 : 0.20
2 0.16 x t25 : 0.20
3 0.25 x 80: o.20
and so on.

The reader may be puzzled that, in the figures above, 0.20 x 100 is shown
as equal to 0.20 rather than 20. It must be remembered, however, that rating does not
stand by itself: it is always a comparison with the standard rating (100) so that, when
the amended time is being calculated, the assessed rating is the numerator of a fraction
of which the denominator is the standard rating. In the case of the 100 standard this
makes it a percentage which, when multiplied by the observed time, produces the con-
stant known as the "basic time" for the element.

Rating
Observed Time x : Basic Time
Standard Rating
For example-

o.t6 min x 125 - o.2o min

100

This basic time (0.20 minutes in the example) represents the time the ele-
ment would take to perform (in the judgement of the observer) if the operative were
working at the standard rate, instead of the faster one actually observed.
If the operative was judged to be working more slowly than the standard, a
example-
basic time less than the observed time would be arrived at, for

80
0.25 min * :0.20 min
100 249
 TIME STUDY: RATING

In actual practice, the multiple Observed Time x Rating is very rarely

exactly constant when taken over a large number of readings, for various reasons
such as-
tr Variations in the work content of the element.
tr Inaccuracies in noting and recording observed times.
tr lnaccuracies in rating.
! Variations due to rating to the nearest five points.

9. Recording the rating

We have discussed the theory of rating at some length and are now in a
position to undertake the complete study.
In general, each element of activity must be rated during its performance
before the time is recorded, without regard to previous or succeeding elements. No
consideration should be given to the aspect of fatigue, since the allowance for recovery
from fatigue will be assessed separately (see Chapter 18).
In the case of very short elements and cycles this may be difficult. If the
work is repetitive, it is possible to rate every cycle or possibly the complete study. This
is done when the short cycle study form (figure 77,page 212) is used.
It is most important that the rating should be made while the element is in
progress and that it should be noted before the time is taken, as otherwise there is a
very great risk that previous times and ratings for the same element will influence the
assessment. For this reason the "Rating" column on the time study sheet in figures 75
and76 is placed to the left of the "Watch Reading" column. It is, perhaps, a further
advantage of the cumulative method of timing that the element time does not appear
as a separate figure until the subtractions have been made later in the offrce. If it did, it
oorate
might influence the rating or tempt the studyman to by the watch".
Since the rating of an element represents the assessment of the average rate
of performance for that element, the longer the element the more difficult it is for the
studyman to adjust his judgement to that average. This is a strong argument in favour
of making elements short, subject to the conditions discussed in Chapter 16. Long ele-
ments, though timed as a whole up to the break points, should be rated every half-
minute.
Rating to the nearest five is found to give sufficient accuracy in the final
result. Greater accuracy than this can be attained only after very long training and
practice.
We may now refer back to the time study form in fltgures 75 and 76. We
have discussed the filling-in of two columns, namely'oWatch Reading" (WR) and the
"Rating" (R), both entries being made on the same line.
These readings are continued for a sufficient number of cycles, at the end of
which the watch is allowed to run on until compared with the clock with which it was
synchronised when started. The 'otime af,ter" can then be noted and recorded. The
study is then at an end. The next step, after thanking the operative for his co-opera-
tion, is to work out the basic time for each element. How to do this is described in the
250 next chapter.
 IhapEuS
Time study: From study
to standard time

1. Summarising the study

At the stage we have now reached, the studyman has completed his obser-
vations at the workplace and has returned to the work study offrce with his study. No
doubt he will later be making further studies on the same job or operation as per-
formed by different operatives, but for the moment we shall consider how he works up
the study he has just taken and enters the results obtained on the analysis of studies
sheet for the operation. Later in the chapter we shall see how standard times are com-
piled from the entries on the analysis of studies sheet.

All the entries made so far on the time study top sheet (figure 75) and the
continuation sheets (figure 76) have been written in pencil. As well the heading details
shown in the data block on the top sheet, there will be the "time before", the first entry
on the study proper; the "time aftef', which will be the last entry; and two entries for
each watch reading made-the rating and the watch reading itself. The ratings will all
be in the column headed "R" bnd will consist of numbers such as 95, 1 15, 80, 100, 75,
105, etc., though until the studyman has had considerable practice he should confine
his ratings to steps of ten, such as 80, 90, 100, etc. In the next column, that headed
"\ry'R", will be the watch readings in decimal minutes. Since watch readings will have
been made at intervals of half-a-minute or less (long elements being rated and timed
every half-minute during the element as well as at the break point which signals its
end), most of the entries will consist of two figures only, with a three-figure entry
occurring whenever a full minute has been crossed. It is usual to omit the decimal
points. This saves the studyman a certain amount of writing and in practice gives
rise to no ambiguity.

Let us assume that the "time before" was 2.15 minutes. The first entry on
the study proper will thus be 215. The next may be 27, indicating that the watch was
read 2.27 minutes after it was started. If the next three entries are 39, 51 and 307,
these will signify that the watch was read at2.39,2.51 and 3.07 minutes after it was
started. Two- and three-figure entries will continue in this way down the sheet until ten
minutes have elapsed, when the next entry will be a four-figure one. Most studymen
then revert to three-figure and two-figure entries again until another ten minutes have
passed, using four figures only for the first entries after the ten-minute intervals. The
study will close with the "time after'o entry, at which time also the ootime off' will be
noted in the data panel on the study top sheet. Every now and then in the study there 251
 may be watch readings without accompanying ratings, when some delay or stoppage
has occurred. These ofcourse cannot be rated, for they are not work.
It should be made a working rule that none of these pencil entries may ever
be erased and replaced. Occasionally a study may contain a very obvious error, of a
sort which may be corrected without invalidating the study. [f so, the correction
should be made in ink, over the original pencil entry, so that it may always be seen
later as a change made in the study office, not at the place where the study was made.
Whenever there is an error about which there is doubt as to how it should be cor-
rected, that part of the study should be ignored. It may be necessary to scrap the
study and make another.
It is good practice to carry out all subsequent work on the study sheets
either in ink or in pencil of a different colour from that used for the initial recordings.
Many study departments make this a standing rule also. There is then no doubt
whatever about what was actually recorded from direct observation and what repre-
sents subsequent calculation. Quite apart from its merits in obtaining orderly process-
ing of the data recorded, the practice helps also to rnaintain the confidence of workers
and their representatives that nothing improper is permitted in the working up of
studies.

2. Preparing the study summary sheet

As will be seen a little later, much of the work necessary before the study
summary sheet can be completed consists of quite simple routine calculations which
may be done by a clerk while the studyman gets on with something else. In the begin-
ning, however, the studyman should do everything himself, until he is so thoroughly
familiar with all the procedures involved that he can not only instruct the clerk on
what has to be done but can also check the calculations easily and quickly. It is also a
good idea to provide the clerk with a calculator to help to reduce the number of mis-
takes and increase the amount of useful information that can be extracted from the
study.
The hrst step is to complete the data at the head of the study summary sheet
(l'rgure 80), copying the details neatly, in ink, from the study sheets. From the time
ofl and the time on, the elapsed time may be calculated and entered. When cumulative
timing is being practised, the elapsed time should of course agree with the final watch
reading. If it does not, there is an error which must at once be investigated. It is no use
doing further work on the study until this is cleared up, for a serious error may be
cause for scrapping the study and starting again. Deducting from the elapsed time the
total "check time"-the sum of the "time before" and the "time after"-yields the net
time. This should agree with the sum of all the observed times when using flyback tim-
ing, or the sum of all the subtracted times with cumulative timing. If flyback timing
has been used, this check should be made before proceeding further, by adding up all
the element times recorded and seeing how the total compares with the net time. It is
unlikely that there will be exact agreement, for the reasons noted earlier, but the dis-
crepancy should be within ! 2 per cent. If it is greater than this, some departments
252 make it their practice to ignore the study and make another.
 When cumulative timing has been used, the .n..n .;:, ffi;r;;.
subtracted times have been obtained and totalled. The comparison then serves as a
check on the accuracy with which the subtractions have been made. Any error should
be investigated and corrected before the work ofextension is undertaken.
On the body of the study summary sheet the studyman next lists in order all
the repetitive elements observed, in order of their occurrence, noting the break points
used on the reverse ofthe sheet.

Some of these repetitive elements may be variable elements, which will have
to be treated in a different way from the constant elements. These variable elements
are therefore listed again in a fresh tabulation below the full list of repetitive elements.
Below the variable elements the studyman next lists any occasional elements
observed, including with them any contingency elements of work which actually
occurred during the study. Below these again are listed any foreign elements and in-
effective time. When these entries have been made, the sheet should provide for a
summarised record of everything that has been observed during the study.

ENTER FREOUENCIES
The next step is to enter against each element listed on the study summary
sheet the frequency with which that element occurred. Repetitive elements, by defini-
tion, occur at least once in every cycle of the operation so the entry to be made against
a repetitive element will read lll,or2f l,etc., indicating that the element concerned
occurs once in every cycle ( 1/ 1), twice (2/ l), or whatever may be the case. Occasional
oosharpen
elements (for example, the element tools") may occur only once every 10 or
50 cycles, when the entry would be 1/10, l/50, or as appropriate. The entries are
made in the column headed "F" on the study summary sheet.

3. Extension: the calculation of basic time

The studyman has now completed the entries in the heading block of the
study summary sheet, listed the elements, entered frequencies and (if necessary) made
a clear sketch ofthe workplace layout on the reverse on the sheet (when appropriate,
the use of a simple instant-print-type camera can save a great deal of time and money;
it is usually necessary to include in the photograph a simple scale, such as a square
rod painted in I cm bands). He must turn next to the calculations which have to be
made on the time study sheets themselves before he can go any further with his study
summary. The results of his calculations will be entered on the time study sheets in ink
or pencil of a different colour from that used when recording observations at the
workplace.
If flyback timing has been used, the studyman may proceed direct to exten-
sion. When using cumulative timing, however, it is first necessary to subtract each
watch reading from the one following it, in order to obtain the observed time for each
element. The entries obtained in this way should properly be styled "subtracted times"
rather than'oobserved times"; they are entered in the third column on the time study
ooST".
sheets, that headed The subtracted times derived when using cumulative timing
are of course exactly equivalent to the observed times entered directly at the 253
 FROI\4 STUDY TO STANDARD TIME

workplace when using flyback timing, so for the sake of simplicity the single term
"observed time" is used during the rest of this chapter to mean both directly observed
and subtracted times.
The next step is to convert each observed time to a basic time, entering the
result in the column headed o'BT" on the time study sheets

i ,lill'l l'

Extension

The effect of extending an observed time for an element to the basic time is
shown graphically in figure 85.

Figure 85. Effect of extension on the time of an element

(a) Pefiormance above standard

OT x (R-100)
Observed Time 100

Basic Time

(b) Pefiormance below standard

Observed Time

254
 FBOM STUDY TO STANDARD TIME

4. The selected time

CONSTANT ELEMENTS
Iri theory the results of all the calculations of the basic time for any single
constant element should be the same, but for the reasons given in Chapter 17 this is
rarely so. It is necessary to select from all the basic times which have been entered on
the time study sheets a representative time for each element. This will be recorded
against the element description on the study summary sheet and will later be trans-
ferred to the analysis of studies sheet as the end result of the study, at least in so far
as that particular element is concerned.

The calculations necessary to arrive at the selected basic time are carried
out on the working sheet. As was noted in Chapter 15, it is quite common to use
simple lined sheets for making the analysis (or, for variable elements, squared paper),
without having any special forms printed. The working sheets, when completed, are
stapled to the time study sheets and filed with them. Much time can be saved and
accuracy can be greatly improved by using a small calculator or computing equipment.
There are various methods of examining and selecting the representative
basic time for a constant element. Perhaps the most common, and in many ways often
the most satisfactory, is by making a straight average of the element times arrived at,
adding all the calculated basic times together and dividing the total by the number of
occasions on which the element was recorded. Before doing this, however, it is usual
to list all the basic times for the element and scrutinise the list, ringing out any times
which are excessively high or low, well outside the normal range. These ringed times
are sometimes styled "rogues". They should be examined carefully.
An exceptionally high time may be due to an error in timing. If cumulative
timing is being used, an error of this sort will be revealed by examining the study,
because an excessively long time for one element will cause shortening of the recorded
time for the next. A high time may also be due to an error having been made in exten-
sion. But perhaps the most common cause, apart from errors, is that there has been
some variation in the material being worked on or in some other aspect of the working
method, which has caused a higher work content on'the particular occasion recorded.
If so, it is necessary to establish the cause and to consider whether it is likely to recur
frequently or only very rarely. If the latter, it is usual to exclude the element basic time
from the total from which the average is derived and then, having calculated the
average time for the element, to carry the excess-over-average time contained in any
ringed times down to contingencies, adding it to any other contingency time which 255
 FROM STUDY TO STANDARD TIME

may have been observed and recorded during the study. In this way the extra time is
fully accounted for, but it is treated as an exceptional event or contingency, which it
properly is. On the other hand, if minor variations in the work content of an element
are at all common, it will be much better not to exclude any calculations at all when
calculating the average. Frequent minor variations should always be treated as signals
to alert the studyman. If they are unavoidable, they at least indicate that studywork
will have to be continued until a large number of observations have been taken on the
element concerned, so that the resulting average of all the basic times may be suf-
ficiently representative. Very often, however, they indicate that a further study should
be made of the operation to find out the reason for them, and, if possible, to eliminate
it.
Exceptionally short times should also be examined with great care. They
too may be due to the studyman's error. On the other hand, they may indicate that a
minor method improvement was adopted on the occasion during which the much
shorter time than usual was noted. If so, it will be well to study the job again, giving
special and more detailed attention to the working methods used.
The approach outlined above is valid so long as the exceptional times are
either very infrequent, or, if frequent, only minor in character. Frequent large varia-
tions indicate that the element is not constant but variable, and it must be treated as
such.
During a time study made on the operation of inspecting and jacketing a
book, one element was described as: "Pick up one book, inspect, initial back end
paper (break point: book closed)". This element was observed 31 times, and the basic
minutes calculated were as shown below:

Basic minules
27 26 28
26 25 25
27 29 27
27 28 27
26 28 26
27 27 25
26 27 26
25 26 26
26 27 @ Gaultv narg
27 26 26
28

It will be seen that one figure has been ringed-the basic time of 0.49 minutes which
arose when a faulty book was encountered, examined and rejected. Excluding this
figure, the total of the remaining 30 basic times is 7.97 minutes, which yields an
average of 0.266 minutes per occasion. At this stage in the studywork the figxe 266
would be entered on the study summary sheet and be carried to the analysis of studies
sheet; but at the end of the calculations for the element, the basic time hnally selected
would be rounded offto the nearest two figures-in this case 0.27 minutes. The excess
work observed in the ringed observation (0.49-0.21 : O.22) would be carried down to
256 the contingencies record.
 Selection by averaging in this way is simple to teach and to understand, and
is readily accepted by both studymen and workers. When the total number of obser-
vations made on an element is relatively s.ail, averaging usually gives a more accu-
rate result than is obtainable with other methods of selection. It does, however, give
rise to a great deal of clerical work when many observations have been recorded, par-
ticularly when short elements have been observed very many times. Consequently,
other methods of selection have been devised to reduce the calculation effort required.
One method, which obviates the necessity for extending observed times to
basic times, is to tabulate the observed times for the element under the ratings
recorded as corresponding to each observation, so as to form a distribution table
against ratings. The table can be compiled direct from the entries made on the time
study sheets at the workplace. For the element in the example above, the distribu-
tion table would appear as follows:

Rating: 80 8J 90 95 lU t05
obsemed 3l 32 30 28 28 27
times 31 30 30 27
30 30 27 27
31 26 28 26
31 27 27 27
28 26 28
29 29 27
29
29

31 155 258 195 190 27 Totals of observed times

Basic times 25 132 232 185 190 28 Total: 792

In the tabulation above, all the 30 observed times from which the basic
times shown in the earlier example were calculated are listed, the one ringed observa-
tion having been excluded. The observed times are then totalled under each rating, and
these totals are then extended by multiplying by the corresponding ratings, to yield the
basic times (totals) shown in the line below. The grand total of all these basic times
comes to 7.92 minutes, which, when divided by 30 (the number of observations) given
the selected basic time for the element-0.264 minutes. This may be compared with
the result of 0.266 minutes achieved by averaging the individual basic times.
A third method also avoids the need to extend each observed time, the selec-
tion being made by constructing a plot as shown in figure 86. In this method there are
two sections to the plot, and two entries are made for each observation, but the entries
are crosses or dots. The left-hand axis contains the time scale and shows the range of
times observed for the element, in this case from 26 to 32. The scale at the top of the
right-hand part of the plot shows the ratings observed, from 80 to 105. To make the
plot, the studyman runs down his study, and each time the element is recorded he
makes a cross against the time observed, and a second cross, also against the
observed time but under the rating observed, on the right-hand side of the plot.
When all these 6,ntries are made, the left-hand side of the diagram will ex-
hibit a frequency distribution of observed times. On the right-hand side, the best 257
 FROM STUDY TO STANDARD TIME

Figure 86. A graphical method of selecting basic time

occasrons observed ratings

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straight line is through the points plotted. The selected basic time for the element can
then be read off by entering the right-hand plot under 100 rating, going vertically
down until the line through the points is reached, and then reading on the scale at the
left the time which corresponds to the intersection.
It is essential that the plot on the left-hand side be completed, in order to
check whether the distribution follows the normal pattern. If it does not, the method
should not be used. Distributions which are irregular-lopsided, skewed, or having
two humps-should be treated as signals that the method will not be reliable, at any
rate in the simple form here described. The different distribution patterns which can be
produced each have significant meanings, indicating different variations in the work
itself, in the operative's rate of working, or in the studyman's rating efliciency; but it
will be better not to get involved in sophisticated analyses of this sort until con-
siderable experience has been gained. The method is illustrated briefly here because it
is typical of several which make use of graphical means to select representative basic
times without extending each observation. Most of them are valid only when the dis-
tribution is normal or when the precise significance of any abnormality is thoroughly
understood. It is recommended that the graphical methods be avoided unless expert
guidance is available. The first two methods described will sufftce for all normal needs,
and have the merit that they are more easily understood by workers or their represen-
tatives.
Before leaving the subject of constant elements, the reader may like to refer
again to the comments made in Chapter 17 about certain manual elements when the
worker is heavily loaded, so that in all probability he normally performs the element at
258 his best natural pace. Such elements are comparatively rare, but when they occur it
may be sufficient to calculate the selected basic time r, ,r;;;ffi;;
times, without recourse to extension. It is essential, however, to have a large number
of observations if this is to be done.

VARIABLE ELEMENTS
The analysis of variable elements presents more difficulty. It is necessary to
find out what it is that causes the basic time to vary, and quite often there may be
several variables to take into account at once. For example, consider the operation of
cross-cutting wooden planks with a handsaw. The basic time needed to make the cut
will vary with the width of the plank, which establishes the length of cut that has to be
made, and also with the thickness of the planks and the hardness of the wood being
cut. If the saw needs sharpening, the cut will take longer; however, this would be con-
sidered to be the use of an incorrect method, and any observations made while the
operative is using a blunt saw would therefore be disregarded.
The first step in the treatment of variable elements is almost always to ex-
tend observed times to basic times. The basic times will then be plotted on squared
paper against the known variables. Thus for variable elements the analysis of studies
sheet takes the form of graph paper, and the graph constructed at the time of sum-
marising the study will probably be attached to the analysis of studies sheet, in place
of the entries made on this sheet for constant elements.
Whenever possible, the basis chosen for the plot should be some variable
which yields a straight line when the basic times are entered. Sometimes this can be
done by using logarithmic paper, when analysis of the operation suggests that the
variability with time may not be arithmetically linear. Quite often, however, it is not
possible to discover a straight-line relationship between time and the main variable, or
with any combination of variables which is tried. In these cases the end product will be
a curved lineo drawn as smoothly as possible between all the plots made from all the
studies on the element. Basic times for the element will then be selected by reading off
the curve at the appropriate point on each occasion on which a standard time has to
be compiled.
The treatment which the studyman would accord to the times derived from
studying the cross-cutting of planks would depend on whether the operation is an in-
cidental one, performed only rarely, or whether it is an element performed many times
each day, forming a substantial proportion of the total work done. In the latter case he
will probably need to build up a series of graphs, each for a different hardness of
wood, with each graph having a family of lines on it, one for each thickness of plank.
Basic times would be plotted on these graphs against length of cut. The relationship
should be linear, so that once it has been discovered the lines can be expressed as for-
mulae, with factors to take into account the variables, thus dispensing with the graphs
for the calculation of basic times. If the element is not of sufficient importance to war-
rant so much detail, the studyman would probably try plotting basic times against the
product: width of plank x thickness of plank, thus combining two of the main
variables. He would also try to establish a factor by which to multiply the relationship
discovered to take account of different hardnesses of wood. The statistical technique
of multiple regression analysis is highly suitable for the calculation of variable times.
However, a full explanation of this technique falls outside the scope of this book. 2sg
 FROM STUDY TO STANDARD TIME

It will be evident that, in general, many more observations of a variable ele-

ment than of a constant element will be necessary before reliable representative basic
times can be established. It is well to recognise this at the outset, so that the studywork
can be planned to span all the different conditions and variables which are likely to be
encountered in practice. It is well also to give close attention from the beginning to dis-
covering the best basis against which to plot the times, essaying trial plots against dif-
ferent possibilities until some satisfactory indicator of the cause of the variable times is
revealed. When the basis of the relationship has been discovered, further studywork
can be directed to filling any gaps in the information so far compiled. If the essential
analysis is left until a later stage, many of the studies taken may turn out to be
needless duplication.
It is not possible to prescribe any one method of approach which will yield
satisfactory results in the analysis of all variable elements. Each must be treated on its
merits. It is here, perhaps more than anywhere else in time study, that close attention
to the detailed methods of working is amply repaid; otherwise it will rarely be possible
to discover just what it is that causes basic times to vary. Even when the causes are
known, there is often scope for considerable ingenuity in devising a simple basis which
will reflect the major variables and reveal a definite and repeatable relationship.

5. Completing the study summary sheet

Having completed his calculations, the studyman is now ready to enter on
the study summary sheet the information which will make it a clear and concise
record of all the results obtained from his observations at the workplace. Against each
of the constant elements listed on the sheet he will enter the selected basic time for the
element and the number of occasions on which the element was observed. The fre-
quencies of occurrence have already been entered. Against the variable elements he
will note the relationship between basic time and the controlling variable, if he has dis-
covered this, or will record a reference to the graph sheet or other study analysis sheet
on which the basic times derived have been analysed.
To complete the summary, he must enter a record of any occasional ele-
ments observed which have not already been included, and also any foreign elements
which may have appeared during the study. Contingency elements and any con-
tingency time extracted during the calculations must be shown. It is usual to express
the contingency basic minutes as a percentage of the total basic minutes of repetitive
work observed during the whole of the study, so that there may be a basis for compar-
ing the contingencies occurring during one study with those in another.
All the entries which have so far been made represent work, in one form or
another. All except any foreign elements will figure later in the calculation of a stan-
dard time for the operation, and since they are all work they will all attract relaxation
allowances (see section 11). Besides the elements of work, however' there may well
have been periods when no work was done during the study, either because the
operative was resting or because he was engaged on one or other of the activities
which were described earlier in this book as "ineffective time". The time so spent must
260 now be totalled and entered on the summary. It is useful to break down such time into
 )M STUDY TO STANDARD TIME

ooineffective
a few main categories, such as "relaxation", time", etc. The entries will all
be in terms of observed times, of course-periods when no work is done cannot be
rated.

6. How many studies?

We dealt with this problem in Chapter 16, outlining a statistical and a con-
ventional method for determining the number of elements and cycles to be studied.
When the working conditions vary, studies must be made in each of the different sets
of conditions which will be met with in practice: at different times of day if at-
mospheric conditions change markedly during the shift, for instance, and on all the
types of material which have to be processed if the material is not rigidly standard.
The studyman must be prepared to study all the work involved in starting
up at the beginning of a shift and in shutting down at the end of it. Start-up and shut-
down times are part of the work and may need a separate work value, or they may be
taken into account (if appropriate) by making an allowance for them when calculating
the standard times for individual jobs. In industries such as printing, presses are not
normally left inked up overnight, as the ink would dry before morning. Time may have
to be allowed for cleaning machines and the workplace, and for changing clothes in
industries where special clothing is required. Activities of this sort are not usually
taken into account in the calculation of standard times for individual jobs but are
more often dealt with by time allowances. Allowances are discussed later in this
chapter: at this point it is sufficient to note that studies will have to be made on all the
ancillary and incidental activities which are undertaken during the working day
before the matter of allowances can be properly considered.
A simple method of determining when enough cycles of a constant element
have been observed-enough, that is, to permit a representative basic time for the ele-
ment to be selected-is to plot the cumulative average basic time for the element each
time a study is made on it and summarised. The plot is started with the basic time
derived from the first study. When the second study comes in, the figure then plotted
is the average, calculated by adding the basic time from the first study times the
number of ubservations during the first study to the product (basic time x obser-
vations) from the second study, and then dividing by the total number of observations
made during both studies. Further plots are made in the same fashion as successive
studies are worked up. When the line on the graph ceases to "wag" and settles down
at a constant level, enough studies have been made on this element. An example is
shown in figure 87.
With variable elements it is convenient to start by making several short
studies which together span the full range of variability, so that an early attempt may
be made to establish the relationship between basic time and the indicative variable.
Subsequent studywork may then be directed to obtaining the information needed to
complete, modify or validate the apparent relationship suggested by the first studies.

7. The analysis of studies sheet

An example of an "analysis of studies sheet" is shown in hgure 81 (Chapter
15). The results obtained in each study on an operation are entered on this sheet by 261
 FBOM STUDY TO STANDARD TIME

Figure 87. Cumulative average basic times for a constant element

ul
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urF

5?lrl
=r
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CUMULATIVE
NUMBER OF OBSERVATIONS

copying from the study summary sheet, as soon aS the study has been worked up. A
form of the type illustrated provides for a list of all the elements which make up a job
or operation, and also for full details in respect of repetitive and occasional elements,
together with a record of the contingency and ineffective times observed. Graphs are
appended to the sheet to record the results obtained from studying variable elements.
When it is considered that enough observations have been made, the next
step is to calculate the final representative basic times for each element. This is done
on the analysis of studies sheet. The process of selection is essentially similar to that
described in section 4 of this chapter, the usual method being to calculate the over-all
weighted average of all the basic times recorded for each element, disregarding any
entries which subsequent studywork has shown to be erroneous. The weighted
average is obtained by multiplying the basic time recorded from a study by the
number of observations of the element made in that study, adding up the products so
derived for all the studies, and dividing the total by the sum of all the observations
made in all the studies.
When these final representative basic times have been calculated for each
constant element, it is a simple matter to calculate the basic time per cycle, per job or
per operation for these elements, by multiplying the time per occasion by the fre-
quency per cycle with which each element recurs. Variable elements cannot be dealt
with in this way, of course. For them, the basic time may have to be read off the ap-
propriate graph, or, if a straight-line relationship has been established, be calculated
from the formula which expresses the line in algebraic terms, or be derived by regres-
sion analysis.
If it is considered appropriate to make provision in the job time for con-
tingencies, the allowance necessary is also calculated on the analysis of studies sheet.
262 The first step in doing this is to calculate the percentage which the total observed con-
 tingencies represent of the total other work observed. Time ;;:":;;.
just as much work as that devoted to repetitive and occasional elements, so con-
tingency time will also be recorded in basic minutes. If the percentage is a very small
one, it will probably be convenient to adopt the figure as the percentage allowance to
be made; but if it comes out at more than about 4 or 5 per cent, the better course is to
inquire into the causes of the contingencies so as to eliminate or reduce them as far as
possible. When action of this sort has been taken as a result of the studies, the percen-
tage observed during the earlier studywork will no longer be valid and it will be neces-
sary to make fresh observations.
At the stage now reached, a basic time has been built up for the job or
operation, including all repetitive and occasional elements and also any small amount
of extra work which may be met with occasionally as a contingency. The compilation
has been done element by element, so that, if at any time in the future the job is
changed slightly by deleting or changing an element or by adding a fresh one, it will
not be necessary to restudy the whole job. The entries on the analysis of studies sheet
will still hold good for all the unchanged elements in the new job sequence, and
therefore it will be possible to make a fresh compilation after studying the new ele-
ments only.
The basic time, however, forms only a part of the standard time which has
to be established for the job or operation. Certain allowances must be added before
the standard time can be derived. These allowances must now be discussed; before do-
ing so, however, it is necessary to state clearly what is meant by two terms which have
been mentioned frequently in the preceding pages but which have not yet been pre-
cisely defined: namely work content and standard time.

8. Work content
ln the chapters at the beginning of this book, the term "work content" was
used frequently to describe what the words themselves suggest: the amount of work
which has to be done to complete a job or operation, as distinct from any ineffective
time which may occur. In time study practice, however, the word "work" is accorded
a meaning which is slightly different from its usual meaning in ordinary English usage.
An observer who was familiar with the word only in its usual sense would say, when
watching an operative at his job, that when the worker was actually doing something
he was working, and that when he was resting or doing nothing he was not working.
In time study practice, however, we are concerned with measuring work in numerical
terms, and for this purpose the word "work" is extended to include not only the
physical labours performed but also the proper amount of relaxation or rest necessary
to recover from the fatigue caused by those labours. We shall see later that relaxation
allowances are made for other purposes besides recovery from fatigue; but for the
moment the important point is that, when in time study we speak of oowork" and set
out to measure it, we define work to include the appropriate relaxation allowance, so
that the amount of work in a job is taken to be not only the time needed at standard
performance to do whatever the job requires but also the additional time which is
considered necessary for relaxation. 263
 FROM STUOY TO STANDARD TIME

9. Allowances
We have seen that, during the method study investigation which should be
carried out before any job is timed, the energy expended by the worker in performing
the operation should ti reduced to a minimum through the development of improved
methods and procedures, in accordance with the principles of motion economy and,
wherever practicable, by mechanisation. Even when the most practical, economic and
effective method has beln developed, however, the job will still require the expenditure
of human efforto and some allowance must therefore be made for recovery from
fatigue and for relaxation. Allowance must also be made to enable a worker to attend
to i'is personal needs; and other allowances (e.g. contingency allowances) may also
have to be added to the basic time in order to give the work content.
The determination of allowances is probably the most controversial part of
work study. For reasons that will be explained later, it is very difficult to determine
precisely tire allowances needed for a given job. What should therefore be attempted is
an objettive assessment of the allowances that can be consistently applied to various
elements of work or to various operations.
The fact that the calculation of allowances cannot be altogether accurate
under all circumstances is no excuse for using them as a dumping ground for any
fac-
tors that have been missed or neglected in making the time study. We have seen how
the studyman can go to great lengths to arrive at fair and accurate time standards.
These stiould not be spoilt by the hasty or ill-considered addition of a few percentage
points here and therJ'Just in case". Above all, allowances should not be used as
"loosening" factors.
The diffrculty experienced in preparing a universally accepted set of precise
allowances that can be applied to every working situation anywhere in the world is
due to various reasons. The most important among them are-

(1) Factors related to the individual. If every worker in a particular working area
were to be considered individually, it might well be found that a thin, active, alert
worker at the peak of physical condition required a smaller allowance to recover
from fatigue than un obit., inept worker. Similarly, every worker has a unique
learning curve which can affect the manner in which he conducts his work. There
is also some reason to believe that there may be ethnic variations in the response
to the degree of fatigue experienced by workers, particularly when engaged on
heavy manual work. Undernourished workers take a longer time than others to
recover from fatigue.
(2) Factors related to the nature of the work itself. Many of the tables developed for
264 the calculation of allowances give figures which may be acceptable for light and
 FROM STUDY TO STANDABD TIME

medium work in industry but which are inadequate when applied to operations
involving very heavy and strenuous work, such as work beside furnaces in steel
mills. Moreover, every working situation has its own particular attributes which
may affect the degree of fatigue experienced by the worker or may lead to
unavoidable delay in the execution of a job. Examples of these factors are:
whether a worker has to perform his work standing up or sitting down, and his
posture during work; whether he has to exert force to move or carry loads from
one place to another; whether the work itself results in undue eye or mental strain,
and so on. Other factors inherent in the job can also contribute to the need for
allowances, although in a different way-for example, when protective clothing or
gloves have to be worn, or when there is constant danger, or when there is a risk
of spoiling or damaging the product.

(3) Factors related to the environment. Allowances, in particular relaxation allow-

ances, have to be determined with due regard to various environmental factors
such as heat, humidity, noise, dirt, vibration, light intensity, dust, wet conditions,
and so on. Each of these will aflect the amount of relaxation allowances needed.
Environmental factors may also be seasonal in nature. This is particularly so for
those who work in the open air, such as workers in the construction industry or in
shipyards.

It
should now be more clear to the reader why it is so difficult to devise an
internationally accepted scheme of allowances to meet every working situation. It
should also be stated here, in very clear terms, that the ILO has not adopted, nor is it
likely to adopt any standards relating to the determination of allowances. The follow-
ing discussion quotes examples of the calculation of allowances under different condi-
tions. They are quoted here as examples for training purposes and not as an ILO
stand on the matter.
It should also be mentioned that this particular aspect of work study has
been the subject of extensive research by various organisations which have put
forward their own recommendations for the calculation of allowances. Of the more
important research carried out, mention should be made of the work of the Max
Planck Institut ftir Arbeitsphysiologie,l of REFA Verband fiir Arbeitsstudien2 and
of G. C. Heyde in Australia.3

10. Galculation of allowances

The basic model for the calculation of allowances is shown in figure 88. It
will be seen from this model that relaxation allowances (which are intended to aid
recovery from fatigue) are the only essential part'of the time added to the basic time.
Other allowances, such as contingency, policy and special allowances, are applied
under certain conditions only.

I G. Lehmann: Praktische Arbeitphysiologie (Stuttgart, Georg Thieme Verlag, 1953).

2
REFA: Methodenlehre des Arbeitsstudiums, vol.2: Datenermittlurg (Munich, Carl Hanser Verlag,
t97l), pp. 299-33s.
I Chris Heyde: The sensible taskmaster (Sydney, Heyde Dynamics, 1976). 265
 FBOM STUDY TO STANDARD TIME

Figure 88. Allowances

Stress
and strain.
environmental

------*
Where
applicable

11. Relaxation allowances

Relaxation allowances are calculated so as to allow the worker to recover

from fatigue. Fatigue may be defined as a physical and/or mental weariness, real or
imagined, existing in a person and adversely affecting his ability to perform work. The
effects of fatigue can be lessened by rest pauses, during which the body recovers from
its exertion, or by slowing down the rate of working and thus reducing the expenditure
ofenergy.
Allowances for fatigue are normally added element by element to the basic
times, so that a work value for each element is built up separately, the element stan-
dard times being combined to yield the standard time for the whole job or operation.
In this way it is possible to deal with any extra allowance which may be required to
compensate for severe climatic conditions, since the element may sometimes be per-
formed in cool weather and sometimes when it is very hot. Allowances for climatic
conditions have to be applied to the working shift or working day rather than to the
element or job, in such a way that the amount of work which the worker is expected to
266 produce over the day or the shift is reduced. The standard time for the job remains the
 FROM STUDY TO STANDARD TIME

same, whether the job is performed in summer or winter, since it is intended to be a

measure of the work that the job contains.
Relaxation allowances have two major components: fixed allowances and
variable allowances.
Fixed allowances are composed of- lor-
(l) Allowances for personal needs. This allowance provides for the necessity to leave
the workplace to attend to personal needs such as washing, going to the lavatory
and getting a drink. Common figures applied by many enterprises range from 5 to
7 per cent.
(2) Allowances for basic fatigue. This allowance, always a constant, is given to take
account of the energy expended while carrying out work and to alleviate
monotony. A common figure is 4 per cent of basic time. This is considered to be
adequate for a worker who carries out the job while seated, who is engaged on
light work in good working conditions, and who is called upon to make only nor-
mal use of hands, legs and senses.

Variable allowances are added to fixed allowances when working conditions

differ markedly from those stated above, for instance because of poor environmental
conditions that cannot be improved, added stress and strain in performing the job in
question, and so on.
As was mentioned above, a number of important studies have been carried
out by various research organisations to try to develop a more rational approach to
the calculation of variable allowances. Most management consultants in all countries
have their own tables. In Appendix 3, we give an example of relaxation allowances
tables using a points system. Many of these tables appear to work satisfactorily in
practice; however, recent evidence indicates that, although many of the fatigue
allowance scales established empirically in a laboratory are satisfactory on
physiological grounds for work involving normal or moderately intensive effort, they
provide inadequate allowances when applied to very heavy operations such as those
connected with furnaces.
For the various reasons mentioned earlier in the chapter, when using one of
the standard scales it is always preferable to check the amount of relaxation time they
yield by carrying out whole-day studies at the workplace, noting the amount of time
which the workers actually spend in relaxation (in one form or another) and compar-
ing this with the calculated allowance. Checks of this sort do at least show whether
the scale is, in general, too tight or too loose.
Relaxation allowances are given as percentages of the basic time. As men-
tioned earlier, they are normally calculated on an element-by-element basis. This is
particularly the case when the effort expended on different elements varies widely (for
example, where a heavy workpiece has to be lifted on or off a machine at the begin-
ning and end of an operation). If, on the other hand, it is considered that no one
element of a job is any more or any less fatiguing than any of the other elements,
the simplest course is to add up all the elemental basic time first and then add the
allowance as a single percentage to the total.
267
 REST PAUSES
Relaxation allowances can be taken in the form of rest pauses. While there
is no hard and fast rule governing rest pauses, a common practice is to allow a l0 to
15 minute break at mid-morning and mid-afternoon, often coupled with facilities for
tea, coffee or cold drinks and snacks, and to permit the remainder of the relaxation
allowance to be taken at the discretion of the worker.
Rest pauses are important for the following reasons:

tr They decrease the variation in the worker's performance throughout the

day and tend to maintain the level nearer the optimum.
tr They break up the monotony of the day.
tr They give workers the chance to recover from fatigue and to attend to per-
sonal needs.
tl They reduce the amount of time offtaken by workers during working hours.

12, Other allowances

It is sometimesnecessary to incorporate allowances other than relaxation
allowances in the compilation of standard time. Three such allowances are described
below.

CONTI NG ENCY ALLOWANCES

Contingency allowances have already been mentioned when we described

the calculations which have to be made to complete the study summary sheet and the
analysis of studies sheet. The allowance provides for small unavoidable delays as well
as for occasional and minor extra work, and so it would be proper to split the allow-
ance into these components, the contingency allowance for work being allowed to
attract fatigue allowance, just as any other item of work does, and the delay part of
the allowance being given with only a personal needs increment. In practice this is a
distinction which is often ignored. Contingency allowances are always very small, and
it is usual to express them as a percentage of the total repetitive basic minutes in the
job, adding them to the rest of the work in the job and adding a relaxation percentage
to the whole contingency allowance. Contingency allowances should not be greater
than 5 per cent, and should only be given in cases where the studyman is absolutely
268 satisfied that the contingencies cannot be eliminated and that they are justified. On no
account should such allowances be used as "loosening" factors or to avoid carrying
out proper time study practice. The duties for which the contingency allowance is
given should be specified. However, in fairness, it may be necessary to give con-
tingency allowances as a matter of course in enterprises where the production work is
not well organised. This further stresses the need to make the conditions and organisa-
tion of work as good as possible before setting time standards and is an incentive to
the management to do so.

POLICY ALLOWANCES

Policy allowances are not a genuine part of time study and should be used
with the utmost caution and only in clearly defined circumstances. They should
always be dealt with quite separately from basic times, and, if used at all, should
preferably be arranged as an addition to standard times, so as not to interfere with the
time standards set by time study.
The usual reason for making a policy allowance is to line up standard times
with the requirements of wage agreements between employers and trade unions. In
several enterprises in the United Kingdom, for example, the incentive performance is
generally set at such a level that the average qualified worker, as defined, can earn a
bonus of 33tlt per cent of his basic time rate if he achieves standard performance.
There is no need to apply a policy allowance to achieve this state of affairs; it is simply
necessary to arrange for the rate paid per standard minute of work produced to be
l33tlt per cent of the basic time rate per minute, and in general it is better to
accommodate any special wage requirements in this way, by adjusting the rate paid
per unit of work rather than the standard time.
There are, however, certain employer-union agreements under which higher
bonuses can be earned, and it may not be politic to seek a revision of the terms of
these agreements to permit the achievement of their terms by modifying the rates paid
rather than the times set. In these circumstances a policy allowance is given to make
up the difference. It may be applied as a factor to the work content or to the standard
time.
This might be an appropriate course to take when standard times are being
introduced to only a small proportion of the total workforce covered by the agree-
ment. Similar policy allowances are sometimes made as temporary additions to cover
abnormal circumstances, such as the imperfect functioning of a piece of plant or dis-
ruption of normal working caused by rearrangements or alterations. 269
 SPECIAL ALLOWANCES
Special allowances may be given for any activities which are not normally
part of the operation cycle but which are essential to the satisfactory performance of
the work. Such allowances may be permanent or temporary; care should be taken to
specify which. Wherever possible, these allowances should be determined by time
study.
When time standards are used as the basis for a payment-by-results scheme,
it may be necessary to make a start-upallowance to compensate for time taken by
any work and any enforced waiting time which necessarily occurs at the start of a
shift or work period before production can begin. A shut-down allowance may
similarly be given for work or waiting time occurring at the end of the day. A cleaning
allowance is of much the same character: it is given when the worker has to give atten-
tion from time to time to cleaning his machine or workplace. Tool allowance is an
allowance of time to cover the adjustment and maintenance of tools.
lt would be possible, after the time necessary to perform any or all of these
activities has been studied, to express the result as a percentage of the total basic time
for the operations expected to be performed during a day and to give the allowance as
an increment included in the compilation of standard times. Indeed, this is sometimes
thought to be the better course with tool allowance; but, in general, it is preferable to
give all these allowances as periods of time per day rather than embodying them in the
standard times. Usually this is fairer to the operatives, and it has the signal advantage
of bringing to the attention of the management the total amount of time which has to
be devoted to these activities, thus prompting thoughts about how it could be reduced.
Some allowances are normally given per occasion or per batch. One such
allowance is set-up allowance, given to cover the time required for preparing a
machine or process for production, an operation which is necessary at the start of
production on a batch of fresh products or components. Set-up time is sometimes cal-
led make-ready time: its opposite is tear-down or dismantling time, for which a dis-
mantling allowance may be given, to cover the time needed for making alterations to
machine or process settings after completing a run of production. Very similar is
change-over allowance, usually given to operatives who are not actually engaged in
setting-up or dismantling, to compensate them for time on necessary activities or
waiting time at the start and/or the end of a job or batch. These allowances should
be denoted as 'Job change-over allowance" or "batch change-over allowance", as
appropriate.
A reject allowance may be included in a standard time when the production
of a proportion of defective products is inherent in the process, but is perhaps more
usually given as a temporary addition to standard times, per job or per batch, if an
occasional bad lot of material has to be worked. An excess work allowance, if neces-
sary, would also be given as an addition to the standard time, to compensate for extra
work occasioned by a temporary departure from standard conditions.
Learning allowances may be given to trainee operatives engaged on work
for which standard times have been issued, as a temporary benefit while they develop
their ability. A training allowance is a similar allowance given to an experienced
worker to compensate him for the time he is required to spend instructing a trainee,
270 while both are working on jobs for which standard times have been set. These allow-
ances are olten given as so many minutes per hour. o.rj",ng scale so that tltc
atlowances taper off to zero over the expected ",
learning " period. Very similar is an
implementation allowance, given to workers asked to adopt a new method or process
to encourage them to attempt an enthusiastic implementation of the new ways and
prevent their losing earnings by doing so. In fact, it is sometimes arranged that their
earnings will actually be increased during the change-over period, so as to give the
new method every chance of success. One system of implementation allowances
credits the workers with ten minutes per hour on the first day, nine on the second. and
so on down to zero.
A small batch allowance is required to enable a worker working on small
batches to decide what to do and how to go about it (from instructions, by experience,
or by trial and error) and then to work up to a standard performance by practice and
repetition. The calculation of this allowance will depend on whether it is a one-of-a-
type batch or not, on the length and batch size or run length and on the frequency of
similar work and its degree of complexity.

13. The standard time

It is now possible to obtain a complete picture of the standard time for a
straightforward manual job or operation, one which is considered to attract only the
two allowances which have so far been discussed in detail: contingency allowance and
relaxation allowance. The standard time for the job will be the sum of the standard
times for all the elements of which it is made up, due regard being paid to the frequen-
cies with which the elements recur, plus the contingency allowance (with its relaxation
allowance increment). In other words-

The standard time may be represented graphically as shown in figure 89.

Figure 89. How the standard time for a simple manual iob is made up
Cont
a ll.

(if performed at a pace

greater than standard pace)

271
 In a case where the observed time is rated at less than standard pace, the
rating factor will, of course, be shown inside the observed time. The contingencies and
relaxation allowances, however, are still percentages of the basic time. The standard
time is expressed in standard minutes or standard hours.
In Chapter 19 we shall discuss the application of time study to operations
involving the use of machinery, in which part of the operation time is taken up by
work done by the machine while the operative stands by. An example of a fully
worked time study is shown in Chapter 20.

272
 Ihapteuq
Setting time standards
forwork with machines
In Chapters 15 to 18 the basic procedures of time study as applied to
manual operations were described. Through the use of the techniques and methods
which were discussed, time standards can be compiled for all jobs in which the
operative works with hand tools or with power tools which he himself manoeuvres, as
distinct from machines which perform part of the operation automatically. Such work
is known an unrestricted work, because the output of the worker is limited only by
factors within his control. A man grinding a cutting tool on an electrically operated
grindstone is engaged on unrestricted work, and so is a worker polishing a metal com-
ponent by holding it against a power-driven polishing mop, for in neither of these
cases does the worker clamp the workpiece securely in position and leave the machine
to get on with the work.
However, it is becoming increasingly common for industrial jobs to be
made up partly of elements performed manually by the worker and partly of elements
carried out automatically by machines or process equipment, with the worker either
being necessarily idle meanwhile or attending to something else. In order to set time
standards for such operations, it is necessary to apply somewhat different methods, in
extension of the basic time study procedures. For some highly complex operations
special techniques have been devised. In the present chapter, only the more generally
applicable methods will be described.

1. Plant and machine control

In many enterprises the machines, plant and equipment together account

for by far the greatest proportion of the total capital invested in the undertaking.
When this is so, the costs incurred in servicing capital, in maintaining the machines,
and in providing against depreciation and for the replacement of the equipment may 273
 well amount in total to more than any other factory expense (excluding the cost of raw
materials and bought components, which is an external rather than a factory expense).
Very often these machinery costs are much greater than the total wage bill for the
plant, so that it is of the utmost importance to make the most intensive use possible of
the machinery and equipment installed, even though this be done at the expense of
labour productivity. Indeed, it may be very sound policy to increase the manning
complement on the machines, if by so doing greater machine utilisation can be
achieved.
Before turning his attention to individual jobs, thereforeo the work study
man will do well to examine first the over-all utilisation of the machinery in the
business; in the enterprise as a whole; in the different departments; and machine by
machine in the case of particularly expensive items. He will then be better placed to
decide the proper objectives for the application of work study in the plant, and will see
clearly whether labour productivity or machine utilisation is of primary importance.
The terms and concepts used in the study of machine utilisation (or plant or
process utilisation) are described below. They are largely self-explanatory. The
relationship between them is shown graphically in figure 90.

Machine maximum time is the maximum possible time during which a

machine or group of machines could work within agiven period, e.g. 168
hours in one week or 24 hours in one day.
Machine available time is the time during which a machine could work
based on attendance time-i.e. working day or week plus overtime.
Machine idle time is the time during which a machine is available for
production or ancillary work but is not used owing to shortage of work,
materials or workers, including the time that the plant is out of balance.
Machine ancillary time is the time when a machine is temporarily out of
productive use owing to change-overs, setting, cleaning, etc.
Machine down time is the time during which a machine cannot be
operated on production or ancillary work owing to breakdown,
maintenance requirements, or for other similar reasons.
Machine running time is the time during which a machine is actually
operating, i.e. the machine available time less any machine down time,
machine idle time, or machine ancillary time.

The machine running time is a matter of fact, observable by direct study at

the workplace. It does not follow, however, that the machine, though running, is
actually operating in the manner in which it should, or has been set so as to perform
in the very best manner of which it is capable. It is useful therefore to introduce
another concept-

Machine running time at standard. This is the running time that should be
incurred in producing the output if the machine is working under optimum
conditions.
274
 TIME STANDARDS FOR MACHINE WORKING

Figure 9O. Explanatory diagram of machine time

Machine maximum time

Machine available time Not

worked

Machine Machine Machine

Machine running time idle ancillary down
timo tima time

-----1
Machine running Low I
time at standard performance

Soulde. Based on a diagram conlained in the B. S. Glossary, op. cit

The most usefulwork measurement method for studying machine utilisation

is work sampling, as described in Chapter 14. This technique gives the information
required with much less effort than would be needed with time study, especially when
many machines are involved.
It is convenient to express the results obtained from studies on machine
utilisation in the form of ratios or indices. For this purpose three indices are com-
monly used.

(l) Machine utilisation index, which is the ratio of

machine running time to
machine available time
and thus shows the proportion of the total working hours during which the machine
has been kept running.
(2) Machine efficiency index, the ratio of
machine running time at standard to
machine running time
A ratio of 1.0 (or 100 per cent, as it would usually be expressed) would indicate the
ideal state, with the machine always performing to the best of its capability whenever
it is running.
(3) Machine effective utilisation index, the ratio of
machine running time at standard to
machine available time
This ratio can be used to provide an indication of the scope for cost reduction that
would be available if the machine were operated at full efficiency for the whole of the
working time. 275
 TIME STANDARDS FOR MACHINE WOBKING

When work measurement has been applied throughout an organisation, it is

an easy matter to arrange for these indices and others like them to be reported to top
management as routine at regular intervals, for they can be calculated quite simply
from the records instituted to maintain labour, output and machine controls. The in-
cidence of idle time, down time and ancillary time can be highlighted by expressing
these figures as ratios in a similar way, using either machine available time or machine
running time as the base.
In process industries, utilisation studies are carried out in much the same
way, the terms and concepts applied in the same fashion but substituting "process" or
some other suitable word for "machine". The principles are exactly the same when
utilisation in service undertakings is considered: in a passenger transport undertaking,
for example, the same useful results could be expected to accrue from studying the
utilisation of buses or trains and expressing the results being achieved in the form of
indices similar to those described above.

2. Restricted work

A common example of restricted work occurs when an operative is running

a single machine and the machine works automatically for part of the work cycle. The
operative may perform the manual elements of his task at standard pace, or faster, or
slcwer; but while this will influence the rate at which the operation is completed, it will
not govern it, because the time during which the machine is working automatically
will remain the same whatever the worker does.
This does not mean, of course, that nothing can be done to shorten the cycle
time. The example of finish-milling a casting on a vertical milling machine which was
discussed in Chapter (pages 139-142, figures 46 and 47) shows what can be
l0
achieved by arranging for some of the manual elements which were formerly carried
out while the machine was stopped to be done while the machine is running
automatically, cutting the next casting. The reduction in cycle time achieved is shown
graphically in figure 91, which compares the situation before and after the method
rtuOy. (A iime study on this operation is shown fully worked out in the next chapter.)
In this example the machine element remains the same in both cases and
takes 0.80 minutes, but the cycle time has been reduced from 2 minutes to 1.36
minutes, a reduction of 32 per cent. In the improved method the operative needs 1.12
minutes at standard pace to perform the manual elements of the job, but some of these
are carried out while the machine is working. Even if the operative were to do all his
manual work at twice the standard pace, this would not reduce the cycle time by half,
but only by some 20 per cent. Thus the output of the worker is limited by factors out-
276 side his control: the work is "restricted".
 TIME STANDARDS FOR MACHINE WORKING

Figure 91. Result of method study on milling operation

Cycle time :2.OO min

1.20 min
BEFORE
method study

Machine idle

0.8O min

F-- 1.'12 min

AFTER
method study

Machine idle

k--0.8o min _____{

Cycle time : 1.36 min---N

Other examples of restricted work occur when-

(l) One or more operatives are running several machines under conditions similar to
those described above.
(2) Operatives are in control of processes, their principal duties being to observe the
behaviour of the processes or instruments recording their behaviour and to take
action only in response to changes in behaviour, state or reading.
(3) Two or more operatives are working as a team, dependent on one another, and it
proves impossible completely to balance the work load of each, with the result
that some workers are left with periods of idleness within the work cycle.

Team working can give rise to restricted work even when no machines are
used. Assembly work carried out in conjunction with moving conveyors usually does.
Even if the conveyor is used simply to transport pieces from one work station to the
next, with each operative taking a component offthe belt to work on it and returning it
when he has finished, a restriction may be imposed by having to wait for the next
piece. Again, when assembly operations are carried out directly on the moving con-
veyor, as is done in motor vehicle manufacture, the conveyor produces conditions
equivalent to those imposed by a static production machine. 277
 It will be convenient to examine first the simpler case of one worker
operating one machine, before considering multi-machine operation.

3. One man and one machine

The usual way of depicting graphically and on a time scale a one-mari-

and-one-machine operation is as in figure 92, which shows the improved method for
the milling machine example quoted above.
The period during which the machine is working is known as the "machine-
controlled time".

It will be seen that the operative carries out part of his manual work while
the machine is stopped, and part while it is running. These parts are called "outside
work" and "inside work", respectively.

Finally, there is the time during which the operative is waiting for the
o'unoccupied time".
machine to complete the cut, i.e. his

278
 TIME STANDARDS FOR MACHINE WORKING

Figure 92. Milling operation: improved method

Cycle time = 1.36 min

Machine-controlled time: 0.80 min -------,

UnoccuPied
F--- outside work: 0.56 min ------+|<- rnside work: 0.56 min -------+F- ,
0.24 min

.10 .20 .50 .60 .70 .80 1.00 1.10 1.20 1.30 1.36
Time scale mi6u1s5
-
Symbols

Machine working

Operative working

Operative not working

In diagrams of this sort, the periods of time during which the operative is
working (and hence the periods of outside and inside work) are calculated and drawn
at standard performance. In figure 92 no account has so far been taken ofrelaxation
or other allowances: manual work has been calculated at standard pace and is thus
shown in basic minutes. Machine-controlled time is of course shown in actual minutes,
and so, using the 0-100 rating scale advocated in this book, basic minutes for manual
work and actual minutes of machine operation are comparable and can be drawn to
the same scale.
When unoccupied time is calculated, the working time must first have been
calculated at standard performance, that is at standard pace and with proper allow-
ance made for relaxation (the calculation of relaxation allowances is discussed
below). In special circumstances the work elements associated with machine operation
may be calculated at some defined rate other than standard, but we shall not be con-
cerned with these in this book.
The diagram in figure 92 looks rather like a schematic representation of a
bicycle pump, and indeed work study men often refer colloquially to such drawings as
"pump diagrams". When seeking to improve the method, the work study man follows
two main approaches. First, he tries to "push the handle down into the pump"-that 279
 TIME STANDARDS FOR MACHINE WOBKING

is, to arrange for some of the manual elements which are being performed outside the
machine-controlled time to be carried out as inside work, thus shortening the work
cycle (this has been done in the present example). Second, he gives close attention to
"shrinking the pump"-making the machine-controlled time as short as possible by
ensuring that the machine is being used to the best advantage, at the correct speeds
and feeds, and using cutting tools which are correctly ground and made of the best
type of cutting steel for the sort of work in hand, so that the machine running time is
machine running time at standard.

4. Calculation of relaxation allowances

In restricted work, it is essential that the personal needs allowance and the
fatigue allowance be calculated quite separately. The reason for this is that the per-
sonal needs allowance has to be calculated not simply on the elements of manual work
contained in the work cycle but on the whole of the cycle time, including the machine-
controlled time. This is because the percentage figures for the allowance are based on
time spent at the workplace rather than on the time actually devoted to work. Fatigue
allowance, on the other hand, is necessitated by work and is calculated on the basic
minutes of work actually performed.
Apart from this difference, relaxation allowance is calculated in exactly the
same way as was described in Chapter 18.
This is not the end of the matter, however. When the allowance has been
calculated, it is next necessary to consider whether the operative can be expected to
take any or all of it within the work cycle or whether it must be added to the sum of
outside work plus machine-controlled time to derive the true cycle time.
If the work cycle is a very long one, and there are lengthy periods of unoc-
cupied time within it, it may be possible in certain circumstances for the whole of the
personal needs allowance and the fatigue allowance to be taken within the cycle, dur-
ing the time when the operative is not working. Such periods can only be considered
adequate for personal needs allowance if they are long enough (say, 10 or 15 minutes),
if they occur in an unbroken stretch, and if it is possible for the operative to leave his
machine unattended meanwhile. This may be done safely if the machine has an auto-
stop mechanism and needs no attention whatever while it is running; alternatively,
when groups of operatives work together it is sometimes possible to arrange for a
neighbour to use some of his own unoccupied time in giving attention to the absent
worker's machine. In textile factories and in other industries in which the processing
machinery is run continuously, perhaps 24 hours a day, it is common to provide
"floating" workers who can fill in at work stations for odd moments and can help to
keep the machines running during short meal breaks if these are taken at staggered
times.
is much more usual, however, especially with cycles of short duration, for
It
the whole of the personal needs allowance to be taken outside the working cycle. In
the milling example which has been illustrated above and which has a cycle time of
1.36 minutes, it would obviously be impossible for the operative to take any of his per-
280 sonal needs allowance within the cycle.
 TIME STANDARDS FOR MACHINE WORKING

Fatigue allowance is a rather different mattbr. Quite short periods of

unoccupied time can be used for recovery from fatigue, provided that the operative
can truly relax during them and is not required to be constantly on the alert or to give
attention to the machine during them, and that he has a seat nearby. It is generally
considered that any period of 0.50 minutes or less is too short to be counted as
available for relaxation, and that any unbroken period of 1.5 minutes or longer can be
reckoned as fully available for recovery from fatigue. Periods of 0.50 minutes or less
would thus be disregarded. For periods of between 0.50 and 1.50 minutes, it is com-
mon to calculate the time which may be considered as effectively available for relaxa-
tion by deducting 0.50 minutes from the actual length of the period and multiplying
the result by 1.5. The effect of applying this calculation to four periods between 0.50
and 1.50 minutes is shown below-

Time calculated as
Actual unbroken period effectively available
of unocctpied time fo r r ecovery J rom fat i gue

0.50 min nil

1.00 0.75 min
t.25 t.t2
1.50 1.50

In the milling machine example, the length of time during which the
operative was not working was only 0.24 minutes, which is too short to be taken into
account for relaxation. In this particular example, the inside work was performed in
one unbroken stretch of 0.56 minutes, but it is quite common in machine operations
for the workers to have to make adjustments or attend to the machine at intervals, or
perhaps carry out manual elements on other workpieces from time to time while the
machine is working, so that within the machine-controlled time there will be separated
periods of inside work and unoccupied time.
The length of the cycle and the manner in which any inside work occurs
thus both affect the way in which relaxation allowance must be treated. Four cases
can be distinguished:

1. All the personal needs allowance and all the fatigue allowance must both be taken
outside the working cycle.
2. The personal needs allowance must be taken outside the cycle, but all the fatigue
allowance can be taken within it.
3. The personal needs allowance and some of the fatigue allowance must be taken
outside the cycle, but the rest of the fatigue allowance can be taken within it.
4. All the personal needs allowance and all the fatigue allowance can be taken within
the working cycle.

The effect of these four cases for four different operation sequences is
illustrated in figure 93. All the four operations have the following characteristics
in common: 281
 TII\4E STANDARDS FOR MACHINE WORKING

Figure 93. Four operations with machine elements

Over-all cycle time

t-t-t-t- t-t-t-l-t-r-t-l-r{-l-r-r{-r-r-r-r-

CASE
2
I--
PNA taken outside,
FA taken inside working cycle

CASE
3
PNA and part of FA taken
outside, remainder of FA inside
t-!-t-l-t-r-t-t- l- l- t-l-t- r-t-t- ]r -t
Part
working cycle FA

PNA and FA taken inside cycle

l+- outside work inside work+l

machine-controlled time

N.B. PNA = Personal needs allowance FA = Fatigue allowance

Machine-controlled time 15 minutes

Outside work l0 basic minutes
Inside work 5 basic minutes
Personal needs allowance: 5 per cent of outside work
plus machine-controlled time 1.25 minutes
Fatigue allowance: 10 per cent of total basic minutes 1.50 minutes

In case 3 there is a period of 1.0 minute within the machine-controlled time

when the operative is not working. By using the method of calculation described
above, 0.75 minutes of this is considered to be available for recovery from fatigue, so
that the remaining 0.75 minutes of the fatigue allowance has to be taken outside the
282 working cycle. In case 4 the assumption has been made that a neighbouring worker
 TIME STANDARDS FOR MACHINE WORKING

could attend to the operation if it should be necessary for the operative to leave his
work station for longer than the ten minutes of non-working time available during the
machine element.
It will be seen that the over-all cycle time differs in each of the four cases, so
that the number of units of output which could be expected over an eight-hour day
also differs:
Over-all Anticipated
cYcle time daily output
(min) (units)

Case 1 27.75 17.3 say, l7

Case 2 26.25 18.3 say, 18 c

Case 3 27.00 17.7 with overtime, l8

Case 4 25.00 19.2 say, 19

The over-all cycle time is the total time in which the job should be com-
pleted at standard performance, and is made up (in the case of operations of the types
so far discussed) of outside work at standard pace, machine-controlled time, and any
portion of the relaxation allowance which has to be allowed outside the machine-
controlled time. If there are no other allowances to be taken into account (e.g. con-
tingency allowance), and an allowance is made for unoccupied time in actual minutes,
the over-all cycle time will be numerically equal to the standard time for the operation.

5. Unoccupied time allowance

In the construction of scale diagrams representing restricted work cycles,
such as those illustrated in figures 92 and 93, it is usual to show all the manual ele-
ments at the times they would take if performed at standard pace. This is convenient
for method study, and for the calculations needed to determine relaxation allowances
and how they may properly be allocated, after which over-all cycle times and hence
anticipated outputs may be calculated.
The next step is to calculate the total period of any unoccupied time, in
actual minutes. For operations of the types discussed, unoccupied time is calculated
by subtracting from the machine-controlled time the sum of all periods of inside work,
in basic minutes, plus any part of the relaxation allowance which may be taken within
the machine-controlled time. It should be particularly noted that for the calculation of
unoccupied time all work elements must be calculated at standard pace.
Standard times for jobs or operations are calculated on the basis of the
work done by operatives-that is, the manual work content of the job-not that done
by machines. For a job made up solely of manual elements (unrestricted work), the
standard time is essentially a measure of the work which the job contains. With
restricted work, however, the standard time expresses something more than this. It
will be recalled that the definition of standard time is as follows:

283
 TIME STANDARDS FOR MACHII

In order to compile the standard time for a restricted operation, therefore, it

is not sufficient simply to calculate the work content (inclusive of relaxation allow-
ances, and the work portion of any contingency allowance considered appropriate),
adding to this perhaps some small further contingency allowance for delays. It is
necessary to add an allowance for any unavoidable unoccupied time which may be
experienced during the machine- (or process-)controlled time.

Before the allowance is made, the work study man must first have satisfied
himself that the unoccupied time is truly unavoidable, and cannot be reduced further
by method improvement or by a reallocation of work or machines. It was noted earlier
that it may be sound management practice to accept a certain amount of unoccupied
time if, by so doing, costly machines can be kept more fully employed, because in
restricted work machine utilisation is often more important than labour productivity.
Unoccupied time allowance is made in actual minutes.

PAYMENT FOR UNOCCUPIED TIME

When standard times are used as a basis for payment-by-results schemes,
the inclusion of unoccupied time allowances in standard times for restricted work may
give rise to payment anomalies, unless special measures are taken to deal with the
problems which arise.
The sort of difficulty which can occur is most easily seen by considering an
example. Let us assume that in a given enterprise there are three jobs, for each of
which the standard time has been calculated as 100 minutes. The first job is made up
wholly of manual elements. The other two are both restricted operations, and for both
the standard times include allowances for unoccupied time-say, 15 minutes in one
case, and 45 minutes in the other.
If all three
workers perform the manual elements of their tasks at standard
pace and all take exactly the allotted relaxation periods, all three jobs will be com-
pleted in the same time (100 minutes). But the operative on unrestricted work will
have been working all the time (except, of course, for the relaxation period) while the
other two will have been idle for 15 and 45 minutes respectively. If payment is made
for unoccupied time at the same rate as that for working time, the more heavily loaded
o'good" jobs or
workers will soon become discontented; jobs will become known as
'obad" jobs according to the amount of unoccupied time they contain; and there will
be reluctance to undertake tasks with the higher work contents.
Usually this diffrculty is dealt with not by modifying the standard times
but by establishing different rates of payment for work and for idle time. To enable
this to be done, it is usual to express standard times not only as totals but also as work
284 credits plus idle time credits (or in similar terms).
 TIME STANDARDS FOR MACHINE WORKING

Thus, in the example cited above, the standard time (100 minutes in each in-
stance) would be shown as being made up of 100, 85 and 55 work credits plus 0, 15
and 45 idle time credits respectively. It may be noted in passing that idle time credits
included in a standard time may be allocated for reasons other than unoccupied time
as discussed above. Idle time credits may sometimes be necessary to compensate for
delays caused by waiting for work or for instructions, or by machine breakdowns.

The scheme to be adopted to make differential payments for work and for
idle time in a particular enterprise is properly a matter of wages administration, rather
than of time study practice, and is thus outside the scope of this introductory book. It
may be noted, however, that any such scheme should be simple to understand, so that
the workers may readily comprehend why jobs taking the same time to complete
attract different payments. The scheme should be negotiated and agreed with the
workers' representatives before it is applied. In a typical scheme, idle time credits
amounting in total to less than 5 per cent of the work credits may be paid for at the
same rate as work credits; idle time amounting to 40 per cent or more of the work
credits at three-quarters of the rate of working; and idle times between 5 per cent and
40 per cent at varying rates in between.
The scheme which will be most appropriate for a particular organisation
will depend on local circumstances, and especially on whether jobs with large amounts
of unoccupied time are exceptional or common. Sometimes variable rates which have
to be read off a curve are adopted, but in general a linear relationship is to be pre-
ferred, and always one which is simple.

The time study man is concerned primarily with measuring the amount of
time needed to complete a job or operation, rather than with whatever arrangements
are agreed for making payment for that time. It is common in industrial wage agree-
ments to take account of different levels of skill required for different operations, by
paying differing rates per minute or per hour of work. Other factors may also be taken
into account in setting payment rates. None of these matters will affect the calculation
of any unoccupied time allowance which may be necessary to compile the standard
time for a job. The time allowance will be in minutes or hours: payment for those
minutes or hours will be negotiable quite separately.
In the scheme mentioned above, relatively long periods of unoccupied time
are paid for at lower rates than those paid for working. In some circumstances,
however, it may be appropriate to pay for both working time and unoccupied time at
very high rates indeed, in which case the payment actually made to a particular
operative for a minute of unoccupied time may be greater than that paid to another
for a minute spent working.
An example is the final machining of a shaft for a turbine-driven electricity
generating set. Such a shaft may be several metres in length, and by the time that the
last stages of machining are undertaken the component will represent a large invest-
ment, in terms of both labour and the costly materials of which it is made. A faulty cut
may result in a diameter becoming undersize, with the result that the whole shaft
would have to be scrapped. The operative is thus burdened with a very heavy respon-
sibility, although the actual operation itself is not particularly complex. Because of this
responsibility the rates paid to the operative, both for working and for any necessarily 285
 TIME STANDARDS FOR MACHINE WORKING

unoccupied time, may be higher than those for the general run of turning operations.
Similar "key" operations or tasks occur in many industries.

6. Multiple machine work

In section 3 the simple case of one man and one machine was examined.
Frequently, however, workers are called upon to look after rqore than one
machine-perhaps many machines-and this poses special problems in time study
work. A common example is that of the weaving shed in a textile mill, where a worker
may attend anything from 4 to 40 looms (perhaps even more), depending on the type
of loom installed and the characteristics of the cloth being woven. Similar circum-
stances are often encountered in engineering industries, for example when workers
operate batteries of screw-making or coil-winding machines. It is usual in work situa-
tions of this sort for the machines to be equipped with automatic cut-out devices
which bring them to a standstill when their tasks are completed or when breaks or
malfunctioning occur.
Tasks of this sort are all examples of restricted work, as the output of the
worker may be limited by factors outside his control. So too are team operations,
whether the team of workers is concerned with the operation of a single machine (as
sometimes occurs in drop-forging), with several machines (a frequent occurrence in
textile operations) or indeed with no machines at all, since restrictions can be imposed
by lack of balance in the amounts of manual work which have to be performed by dif-
ferent members of the team.

LOAD FACTOR

The load factor is sometimes known by the alternative terms "extent occu-
pied" or 'owork load". In the simplest case of one man operating one machine, as illus-
trated in figures 92 and 93, if the over-all cycle time is ten minutes and the amount of
manual work contained within the cycle totals only one standard minute, the load fac-
286 tor would be one-tenth, or 10 per cent.
 TIME STAND/

The reciprocal of the load factor therefore indicates the number of machines
which the worker could theoretically tend: in this example, ten machines. In practice,
other factors have to be taken into account, so that the load factor can be taken only
as a very rough first indication of the number of machines which can usefully be allo-
cated to a worker. It does sometimes occur that the work elements consist solely of
unloading finished pieces from machines which have stopped automatically, loading
fresh pieces and restarting the machines; and if all the machines are alike and are
working on exactly similar pieces, it may be possible to achieve the ideal sequence of
operation, with the worker able to operate the number of machines indicated by the
reciprocal of the load factor. Much more commonly, however, differences occur in the
machines or in the work, and frequently attention has to be given to the machines
while they are running, with the result that the worker cannot always get to a machine
at the exact moment when attention is needed. The delays which then occur are
known as machine interference.

MACHINE INTERFERENCE

When studying multiple machine working or team working (with or without

machines), the work study man has first to examine the methods of working with the
object of devising a sequence of operations which will result in the best balance and
thus the least interference, and then to use time study techniques to measure the
amount of interference which will occur even when the best sequence has been deter-
mined. These tasks may sometimes be extremely complicated. They often call for the
use of specialised methods which are beyond the scope of this book.
Ifthere are only a few workers in the team, or if one or two workers are
operating only a few machines between them, simpler methods will suffice. Operation
sequences can be plotted and examined on multiple activity charts (described in
Chapter l0), supplemented by cycle diagrams similar to those shown in figures 92 and
93. The diagrams for each machine are drawn one below the other, to the same time
scale. A simple example, that of an operative working three machines, is shown in
figure 94.
In this example there is no inside work, so that when a machine has been
started the operative can turn his attention to another. The sequence in which he does
so is indicated by the small vertical arrows. It will be seen that, with this particular
routine, machine C is operated without any delays occurring; but the result of doing
this is that both machine A and machine B switch themselves off at the end of their 287
 TIME STANDARDS FOR MACHINE WORKING

M Figure 94. Machine interference

A
c
H
I

N
interforence
E

respective operations and then have to wait a while before the operative can get to
thern. The interference is indicated on the cycle diagrams for machines A and B by
grey arcs.

I NTERFERENCE ALLOWANCE

By extending the methods so far described, using the same charting conven-
tions and principles, it is possible to establish work sequences and to calculate inter-
ference for a fairly wide range of multiple machine operations, including many
which will be met with in the engineering and allied industries, and especially those in
which machine stoppages occur in regular, predictable fashion rather than at random.
In coil-winding, for example, the winding machines switch themselves off when the
coil is completed, and contingencies (such as wire breaks) are rare.
For these simpler forms of multiple machine operation, when an operative
has only a few machines to look after and the work being done is of a cyclic nature,
with definite beginnings and ends of the work cycles, standard times may be
calculated and expressed exactly as for unrestricted work: that is, as so many stan-
dard minutes (or hours) per piece, per job or per operation. This is quite common in
engineering machine shop operations, especially when workers operate several
machines in sequence. For these situations standard times are compiled as described
earlier in this book, on the basis of the work content for each job or operation. There
is no need to consider machine interference when compiling the standard times,
though it may be necessary to take this into account when making output predictions
248 and other production control calculations. It will be necessary, however, to provide
 TIME STANDARDS FOR MACHINE WORKING

allowances in the standard times for any unavoidable unoccupied time which may
be experienced as a result of working with the machines, and this too may be done
as described above.
When output is continuous rather than cyclic, and especially in process in-
dustries, it is more usual to establish standard times for some convenient volume,
weigh! or length of outpu! rather than per piece or per operation. Thus, in weaving,
the standard times may be compiled and expressed as so many standard minutes per
100 metres of cloth woven (this is in fact one of several ways of stating time stan-
dards for weaving). When this is done, the focus is shifted from the amount of manual
work contained in the operation to the output which may be expected from the
machines, though output calculations must of course take into account the quantity of
manual work involved in tending the machines. Unoccupied time is of interest, and
almost always has to be determined, not for the purpose of making an allowance in
the standard time but rather as an indication of the number of machines which a
worker can attend. For the calculation of standard times the allowance which has to
be taken into account is interference allowance-the times during which some of the
machines will be stopped while waiting for the operative to get to them.

A case in point is that of a weaver looking after a set of looms. Stoppages in

the weaving operation depend upon many circumstances. The strength of the yarn,
and hence the frequency of breakages, is inlluenced by the way the materials forming
the warp and weft have been prepared, and also by the temperature and humidity
within the weaving shed, both of which may change markedly from time to time dur-
ing a shift. The state of maintenance of the looms also affects stoppages, while the
speed and skill of the weaver have a further influence, since a skilled operative can
often prevent stoppages by anticipating trouble and taking preventive action.
In circumstances such as these, it is necessary to evaluate unoccupied time
(for work loading and team balancing) and interference (for compiling standard times)
by extended studies on the shop floor, covering all the different working conditions
and all the different counts of yarn (in weaving) or different materials which have to be
worked on. Studies may have to continue for days or weeks, or sometimes extend over
several months. Work sampling is an appropriate technique to use for this purpose,
and was originally developed expressly for textile operations. It is much more
economical than time study, which would be much too long-winded and detailed for
this type of observation in any but the smallest shops. Using work sampling, for
example, a studyman in a weaving shed can record all the information needed while
observing the operation of 10 or 12 looms, which would be impossible with ordinary
time study practice.
In an introductory book of this nature it is not possible to cover in detail the
specialised methods which are adopted in advanced work study practice to evaluate
interference and to calculate interference allowances in complex multiple machine
situations. For the most part, these methods are based on statistical procedures and
probability theory, and are intended to permit reliable predictions to be made without
recourse to either time study or work sampling. For this purpose a number of for-
mulae, curves and sets of tables have been compiled to assist in the determination of
interference, and hence probable output, for various worker/machine combinations.
The systems, if used with care, offer the prospect of considerable economy of study 289
 TIME STANDABDS FOR MACHII\

time in certain specialised, but complex, multiple machine and teamwork situations.It
is essential, however, that any predictions made on the basis of formulae and tables
should be validated by direct study at the workplace, so that full account may be
taken of local working conditions.
The time study methods described earlier in this chapter, together with work
sampling (as described in Chapter 14), will usually be found adequate for the calcula-
tion of reliable time standards for the majority of the machine working situations
likely to be encountered in general industrial practice. Those readers who are faced
with the task of determining standards for complex multiple machine operations may
find it useful to consult more advanced texts. It is recommended, however, that the
more specialised methods should not be attempted until the work study man has had
suffrcient experience of both time and work sampling to be sure that he can use these
techniques to verify any statistical predictions made.

In the next chapter an example of a fully worked time study is shown. The
study is one taken on the operation of milling a casting, which was the subject charted
on a multiple activity chart in Chapter 10, and for which a cycle diagram appears in
section 3 ofthe present chapter.

290
 IhapterZO
Example
of a time study

In discussing the making of a time study thi'oughout the previous four

chapters, we referred to the example based on the milling of a casting which was the
subject of the multiple activity chart described in Chapter 10. The complete time
study is shown in this chapter. A careful study of the forms shown in the illustrations
should enable the reader to follow in detail the processes by which a time study is
worked up and a standard time is compiled.

This particular example has been chosen because-

(a) itissimple;
(b) ithas already been the subject of a method study;
(c) it includes both manual and machine elements;
(d) it is typical of the sort of operation met everywhere in the engineering industry
and in other industries using machines and semi-automatic processes.

The forms used are simple general-purpose forms such as those illustrated
in Chapter 15. Although all the entries made on the forms will be handwritten, it is
usual to space the lines for use with a typewriter because occasions may arise on
which it is required to produce fair copies of original studies for discussion or circula-
tion.
The study illustrated in this chapter was not the first one on this operation.
The elements and break points were defined at the time the method study was under-
taken, and were then set out on a card prepared and filed by the work study depart-
ment. This is a useful practice when it is expected that an operation will be studied
several times, perhaps by different studymen. It ensures that the recordings made on
all the studies are comparable. The elements and break points are shown in figure 95.
Although the example which has been studied in detail is a simple one for a
manufacturing industry, exactly the same procedure is carried out for non-
manufacturing operations or for any other.work which is time-studied for the purpose
of setting time standards. Entirely manual operations, such as assembly, would be
treated'in exactly the same way. 291
 EXAMPLE OF A TIME STUDY

Figure 95. Card giving details of elements and break points

No.1

Part: 8.239 Gear case. Drawing:23911

Material: ISS 2 Cast iron.
Operation: Finish-millsecond face.
Machine: No.4 Cincinnati vertical miller.
Fixture: F.239.
Cutter: 25 im. TLF
Gauge: 23917. Surface plate.

Elements and Break Points

A. Pick up casting, locate in fixture, lock two nuts' set guard, start
machine and auto feed. Depth of cut 2.5 mm. Speed 80 r.p'm'
Feed 40cm/min.
Break point.' Machine commences cut-

B. Hold casting, break milled edge with file, clean with com-
pressed air.
Break point; Air gun dropped on to hook.
C. Move depth gauge to casting, check machined surface, move
gauge away.
Break point: Left hand releases gauge.

D. Pick up machined casting, carry to finished parts box and

place aside, pick up next part and position on machine table.
Breuk point: Casting hits table.

E. Wait for machine to complete cut.

Breuk point: Machine ceases to cut.

F. Stop machine, return table, open guard, unlock fixture, re-

move tnachined casting and place on surface plate.
Break point: Casting hits surface plate.

G. Clear swarf from machine table with compressed air.

Brectk point: Air gun dropped on to hook.

y'fore.. Elements B, C and D are inside workcand are performed on a casting which has already
been machined while the milling machine is cutting the next casting. Element D includes bringing up into
292 a handy position a fresh casting which will be machined alter the one now in the machine.
 Figure 96. Sketch of part and of workplace layout
(on reverse of time study top sheet)

A sketch of the workplace layout is generally more necessary in assembly or material-

handling studies than in studies of machine shop operations where workplaces are likely to be the same
for alljobs on the machines. The part should be sketched showing the surfaces machined; in the case ol
capstan lathes, tool set-ups should be included. This is best done on squared paper and may be on the
back of the time study top sheet, if desired, in order to keep all the information relevant to the study on
one sheet. To facilitate sketching, the reverse ofthe top sheet is often printed as squared paper.

(o) Skelch of gear-case casting showing surface to be machined and dimension

(b) Layout of workplace

MiUing

T
B
E'
q

Gangway 293
 EXAMPLE OF A TIME STUDY

Figure 97. Time study top sheet

All the information in the heading block at the top of the form (except time off and elapsed
time) was entered before the stop-watch was started and study commenced.

Ifthe study had been the hrst one on this operation, the studyman would have entered in full
the element descriptions and break points in the column headed "Element description" on the left-hand
side ofthe page. In the present instance this was not necessary, as the card shown in figure 95 listed all
the details. The studyman should watch a few cycles of the operation to make sure that the listed
method is being used, and to familiarise himself with the break points, before starting to record. The ele-
ments were identihed simply by the letters A to G.

At exactly 9.47 a.m. by the study offrce clock (or the studyman's wrist-watch) the stop-
watch was started. It ran for 1.72 min before element A of the first cycle started, so this time is entered
at the beginning of the study as the 'oTime before". Since this was a study using cumulative timing, the
watch ran continuously throughout. When the study was broken off after observing 18 cycles, the
studyman allowed his stop-watch to run on until the study offrce clock reached the next full minute (at
10.25 a.m.), noted the "Time after", and stopped his stop-watch. These terminal entries will be found
at the end ofthe recordings in figure 98.

The four columns used in cumulative timing are respectively'oRatingo'(R), "Watch reading"
(WR), "Subtracted time" (ST) and "Basic time" (BT). The placing of the rating colirmn first is logical
and encourages the observer to rate while the element is in progress and not to wait for the watch
reading. If flyback timing had been used, the WR column on the form would not be necessary.

Only the entries in the two columns headed R and WR were made during observations at the
workplace. The other two columns were completed in the study ollice after observations had been dis-
continued. In practice, the "Rating" and "Watch reading" entries would be made in pencil while those
in the "Subtracted time" and "Basic time" columns would be made in ink or with a pencil of a different
colour from that used for the observations.

The studyman numbered the cycles observed, from I to 18, with ringed figures at the left of
the "Element description" column.

When entering watch readings there is no need to use decimal points. The first entry (Time
before, 172) indicates a time of 1.72 minutes. The next watch reading was made 1.95 minutes after the
watch was started, but it is only necessary to enter 95. The third entry of 220 indicates that the reading
was made at 2,20 minutes after starting; the entries then revert to two figures only until the next minute
is passed. During cycle number 15 (recorded on hgure 99) the total study time passed 30 minutes,
which is the time taken by the hand on the small inner dial on the watch to complete one revolution. As
the study continued into a further revolution of the small hand, subsequent watch readings revert to I
again. It will be seen that the recording against element F of cycle 15 was 106, which of course means
31.06 minutes after the watch was started.

Element E-"Wait for machine to complete sg1"-ls not work, and was therefore not rated.
It will be seen that there is no entry against this element in the "Basic time" column.

294
 EXAMPLE OF A TIME STUDY

TIME STUDY TOP SHEET

DEPARTMENT: Machine Shop - Millino Section SIUUY NO. I/
OPERATION : Finish-mill second face M.S. No, I SHEET No. / OF 5
IIME UFI-: IU.Z5 A.M.
PLANT/MACHINE: Cincinnati No.4 vertical miller No. 26 TIME ON: 9.47 a.m.
TOOLS AND GAUGES: Fixture F 239' Cuuer 25 cm TLF ELAPSED TIME: 38.O0
Gauge 239/7: Surface plate OPERATIVE:
CLOCK No.1234
PRODUCT/PART: 8.239 Gear Case No. 239/ | STUDIED BY:
DWG. No. 8.23911 lSS.2 MATERIAL: Cast iron DATE:
QUALITY: As drawins CHECKED:
NOTE: Sketch the WORKPLACE LAYOUT/SET-UP/PART on the reverse or on a separate
sheet and attach
ELEMENT DESCRIPTION R WR ST BT ELEMENT DESCRIPTIOT\ R WR ST BT
Time before 172 @ A 80 622 32 26
o A tto 95 23 25 B 85 50 28 24
B 100 220 25 25 c 85 63 t3 fi
Elements & B.P. C 100 32 t2 t2 D 85 83 20 t7
as Card No.l264 D 95 52 20 19 E 703 20
E 77 25 F 105 26 23 24
F 110 300 23 25 G 85 38 12 to
G fio o8 o8 o9
@ A 80 70 32 26
@ A n0 3t 23 25 B 85 97 27 23
B 95 58 27 26 c 85 810 13 11
c 95 7t 13 12 D 85 30 20 t7
D t00 89 t8 t8 E 53 23
E 412 23 F t05 76 23 24
F 105 37 25 26 G 85 88 l2 10
G 100 47 to t0
@ A 95 915 27 26
@ A l05 72 25 26 B 95 42 27 26
B t05 97 25 26 c 105 54 t2 t3
c 95 510 13 12 D 80 77 23 t8
D 110 28 t8 20 E 97 20
E 53 25 F 95 020 23 22
F to0 78 25 25 G 100 30 to to
G 95 90 12 t1

418 440

295
 EXAMPLE OF A TIME STUDY

Figure 98. Time study continuation sheet

The recordings covered three sheets in all. Figure 98 shows the hrst ofthe two continuation
sheets, and it will be seen that it is numbered in the top right-hand corner: Sheet No. 2 of 5. The
analysis sheet and study summary sheet eventually completed the set of five sheets, all of which were
stapled together after the study was worked up.

Besides the element ratings and timings, continuing as on the top sheet, two interruptions
o'Break for tea". Neither of these was rated, of
were recorded on this sheet: "Talk to foreman'', and
course. The first was taken account of when considering contingencieso while the second was covered
by the relaxation allowance made when the standard time for the operation was compiled.

296
 EXAMPLE OF A TIME STUDY

STUDY No.: 77 IUE STUDY CONTINUATION SHEET I SHCCT No.2 OF 5

ELEMENT DESCRIPTION B WR ST BT ELEMENT DESCRIPTION R WR ST BT
@ A 105 55 25 26 @ A 115 86 25 29
B 115 78 23 26 B 95 1713 27 26
c 95 9t 13 12 c 75 28 t5 1t
D 85 | 113 22 t9 D 85 50 22 t9
E 36 23 E 68 t8
F 80 68 32 26 F 115 90 22 25
G 95 80 l2 11 G 80 1 803 13 t0

@ A 75 1218 38 28 @ A 95 30 27 26
B 110 40 22 24 B 95 55 25 24
c 105 52 12 t3 c 100 67 12 12
D 100 70 t8 t8 D 95 87 20 19
E 300 30 E 1 902 15
F 115 25 25 29 F 95 30 28 27
G 105 35 10 t0 G 75 42 12 09

Talk to foreman 75 40 Break for tea 2554 612

o A 105 t400 25 26 @ A 85 86 32 27
B 100 25 25 25 B 80 2618 32 26
c 95 38 t3 12 c 85 33 15 t3
D 95 56 t8 t7 D to0 53 20 20
E 81 25 E 68 15
F 100 509 28 28 F 85 96 28 24
G 85 21 l2 t0 G 95 2708 12 tl
@ A 95 43 22 21 @ A 80 40 32 26
B 80 75 32 26 B to0 65 25 25
c 95 88 13 t2 c 85 80 t5 t3
D 95 t608 20 t9 D 95 2800 20 t9
E 25 17 E 22 22
F t05 48 23 24 F 80 54 32 26
G 85 61 t3 1t G 105 64 t0 10

631 I 203

297
 EXAMPLE OF A TIME STUDY

Figure 99. Second continuation sheet

The first entry on this sheet recorded another interruption-the patrol inspector, having
checked three workpieceso drew the operative's attention to some feature of them and discussed them
with him. The time taken to do this, like that recorded on the previous sheet against "Talk to foreman",
was later entered as a contingency.

After cycle number 16, a lresh element of work occurred-helping the labourer to move
boxes of work off and on to the truck. This was an occasional element, in contrast with elements A to G
which were repetitive. The studyman rated and timed the element, and it will be noted that, since the ele-
ment ran on for rather over a minute in all, the studyman made a rating and a watch reading at the end
of each of the first two half-minutes, as well as during the last part of the element. This practice, which
makes for greater accuracy, was referred to in section 9 ofChapter 17.

Back in the study oflice after breaking off observations, the studyman first completed the
"Time off' and "Elapsed time" entries in the heading block on the top sheet, and then set about
calculating the subtracted times, by deducting each watch reading from the one which follows it and
entering the result in the third column, headed ST. It will be seen that he totalled these subtracted times
at the loot of each page, and carried forward the subtotals to the sheet shown opposite, where they were
added up to yield 35.20 minutes. When the time before and the time after were added to this hgure, the
result was 38.00 minutes, which agreed with the elapsed time and thus afforded a check that the work
of subtraction had been done correctly.
ooextension": multiplying each subtracted time by the percentage rating
The next step was
recorded against it to yield the basic timeo entered in the fourth column. Extension is easily and quickly
done with the aid of a pocket calculator. The calculation is made to the nearest second decimal place:
that is, to the nearest one-hundredth of a minute. Thus 0.204 would be shown as 20, and 0.206 minutes
as 2l-which leaves the problem of what to do with 0.205. Evidently, in this study oflice the standing
rule was to take half-hundredths of a minute down rather than up, as can be seen by the entry against
element G of cycle 15. Here, the rating was 105 and the subtracted time 10, so that the extension yields
0.105 minutes to three places. This has been shown as 10, the half-hundredth having been taken down.
Other instances will be found in the study. Most study olfices apply the reverse rule: that is, taking
middle times up.

298
 EXAMPLE OF A TIME STUDY

sruDY No.: t7 I TIME STUDY CONTINUATION SHEET I sHEErNo.3oF5

ELEMENT DESCRIPTION R WR ST BT R WR ST BT
Patrol inspector checks @ A 100 7t 27 27
3 pieces: drscuss a966 t02 B 100 96 25 25
c 95 609 13 12
@ A 95 93 27 26 D 75 34 25 19
B 80 t023 30 24 E 52 t8
c too 36 t3 t3 F 100 77 25 25
D too 56 20 20 G 75 92 l5 tt
E 74 18
F 80 106 32 26 148
G 105 t6 10 10

@ A 80 49 33 26 Watch stopped 10.25 800

B 85 77 28 24 a.m. (elapsed time
c 105 89 12 t3 3e.00)
D to0 207 t8 18 Time after 108
E 30 23
F 95 57 27 26
G 85 70 13 11

Help labourer unload 85 320 50 43

boxes of new castings 95 70 50 48
and load finished worl 95 90 20 t9 Check on subtracted 418
on truck (30 new + 30 times 440
fin. in boxes of l0) 631
@ A too 417 27 27 1203
B 85 49 32 27 680
c 85 64 t5 13 1 4t)

D 85 86 22 t9 7520
E 509 23
F to0 34 25 25 Time before 172
G t05 44 t0 10 Time after 108

Elapsed 7800

680

299
 EXAMPLE OF A TIME STUDY

Figure lOO. Working sheet

The repetitive elements A, B, Co D, F and G were all constant elements, and selected basic
times for tlem were obtained by averaging. As was noted in Chapter 15, study analyses take several
forms and for this reason it is not usual to have specially printed sheets for them. Ordinary lined or
squared paper serves very well, and when the time study top sheet has been printed on the reverse as
sqirared paper (to facilitate sketching), it will do well enough to use the back side of a top sheet, entering
at the top the study and sheet numbers. For a simple study the analysis is often made straight on to the
ooElement
study summary sheet, a few extra columns being ruled in the space headed description''.

Methods of obtaining the selected basic times are discussed in Chapter 18. In this instance,
inspection of the basic times tabulated under elements A, B, Co D, F and G showed no anomalies, and
theiefore no need to ring out "rogue" times. For each of these elements the basic times have been
totalled, and the selected basic time was calculated by dividing the total by the number of observa-
tions (18).

oowait
No figures were listed under element E, for machine to complete cut". This was unoc-
cupied time, which was not rated in the study. The actual length of unoccupied time experienced in the
various cycles observed depended on the speed with which the operative carried out the inside work
which he performed on another casting while the machine was cutting automatically.

The time the machine took to make the cut, while on automatic feed, did not vary from cycle
to cycle because it was determined by the rate of feed at which the machine was set and the length of
cut to be made. It could thus be calculated quite easily. In this study the machine-controlled time
started at the end of element A and ended with the conclusion of element E. The machine-controlled
time can therefore be obtained from the study sheets by subtracting the watch reading against element
A from that against E. This has been done, the results being tabulated under "MCT" at the right-hand
side of the working sheet. These times are of course actual minutes, not basic times.

It will be seen that two of the MCT entries have been ringed out. The studyman did not enter
any explanation of unusual events on his record, and inspection of the observations for the cycles in
which these rogue times occurred does not provide any conclusive explanation. Possibly the explana-
tion for the shorter time is to be found in the fact that the operative can start the cut on hand-feed
before locking on the auto-feed, and on this occasion, unnoticed by the studyman, he spent longer on
hand-feed than usual. The explanation for the longer time in cycle 17 may be that the operative failed to
switch the machine off quite as quickly as usual on this occasion, and again this escaped notice. The
two ringed times were excluded from the total of 13.05 actual minutes for the machine-controlled times,
so that this total was divided by l6 instead of 18 to derive the average MCT of 0.8 16.

Element Eo the unoccupied time, was dealt with by subtracting the total of the selected basic
times for elements B, C and D, the inside work elements, from the average MCT. The resulting figure
for the average unoccupied time was 0.257 minutes.

At this stage in the calculations, it is usual to make use of three decimal places for the
selected basic times, and to retain the third place on the study summary sheet and the analysis of
studies sheet.

300
 EXAMPLE OF A TIME STUOY

Study No. /7 WORKING SHEET Sheet 4 of 5

Element: A D MCT

(Basic times) (Actual

minutes)

Cycle No.

1 25 25 12 19 25 09 82
2 25 26 12 18 26 10 81

3 26 26 't2 20 25 11 81

4 26 24 11 17 24 10 81

5 26 23 11 17 24 10 83
6 26 26 13 18 22 10 82
7 26 26 12 19 26 11 81

8 28 24 13 18 29 10 82
9 26 25 't2 17 28 10 81
10 21 26 12 19 24 11 82
11 29 26 11 19 25 10 82
12 26 24 12 19 27 oe@
13 27 26 13 20 24 11 82
14 26 25 13 19 26 10 82
15 26 24 13 20 26 10 81
16 26 24 13 18 26 11 81
17 27 27 13 19 25 10@
18 27 25 12 19 25 11 81

Totals 4.69 4.52 2.20 3.35 4.57 1 .84 13.05

Occasions 18 18 18 18 18 16

Average 0.261 0.251 0.122 0.186 0.254 0.102 0.816

MCT : 0.816 Actual minutes

B+C+D : 0.559 Basicminutes

Element E (unoccupied I : J.zgl

301
 EXAMPLE OF A TIME STUDY

Figure lol. Study summary sheet

The study summary sheet, when completed, was stapled on top of the other lour study
sheets and was eventually filed with them. The sheets which have been usedfor recording observations
at the workplace often become somewhat dirty as a result of the conditions in which they have to be
used. Moreover, because o[ the speed with which the observations have to be written down, the
studyman may have used many abbreviations, and perhaps his hurried writing may be diffrcult for
anyone except the studyman himself to read, The study summary sheet therefore not only presents con-
cisely all the results obtained from the study but also records in the heading block, in ink and neatly
written, all the information about the operation which was originally entered on the time study top
sheet.

The repetitive elements A to G, excluding E, were entered first, and it has been noted that
three of these were inside work and the other three outside work. The entries in the column headed BT
are the basic times per occasion, and were taken from the working sheet shown in figure 100. For each
ol these elements the frequency of occurrence is shown as 1/1, indicating that each occurred once in
every cycle ol the operation. The times calculated for the machine element, and hence the unoccupied
time (element E) are shown below. The column headed Obs. shows the number of observations of the
element which have been taken into account in deriving selected basic times. This information will be
carried to the analysis of studies sheet where it will be of use when the final selected basic times are
derived for the compilation of the standard time.

Under the heading "Occasional elements and contingencieso'is shown the basic time for the
element of helping the labourer to load and unload boxes of castings. It is noted that this element was
observed once only, and that its frequency ought to be l/30 since three boxes often fresh castings were
brought, and three boxes of finished castings loaded. The other two non-repetitive occurrences observed
were "Talk to foreman"o and 'olnspector checks three pieces and discusses". Neither of these periods
was rated, so the times are shown in actual minutes (a.m.).

Finally, the studyman recorded, in actual minutes, the amount of relaxation taken during the
period of the study.

Basic times were entered to the third decimal place, and have been carried forward in this
lorm to the analysis of studies sheet. It may be thought that this is a degree of reltnement which is not
warranted in view of the accuracy of the data on which the entries are based. There is a good reason for
the practice, however. If it is eventually decided to make the final selection of basic times, on the
analysis of studies sheet, by the process of averaging, each of the entries from this study will be mul-
tiplied by the corresponding number of observations to yield the total basic minutes observed for the
element. The totals flrom all the studies taken on this operation will be added, and an average obtained
by dividing by the aggregate number of observations. At that stage, when the whole chain o[
arithmetical calculations has been completed, the final selections will be expressed to the nearest second
decimal place only, that is to the nearest one-hundredth of a minute.

302
 EXAMPLE OF A TIME STUDY

STUDY SUMMARY SHEET

UErAH tMEN I Mlacntne SnoD
',. sEU I tUN: MililnO STUDY No.:77
OPERATION: Finish mtll second tace M.S. No.: 9 SHEET No.: 5 OF 5
uAt ts:
PLANT/MACHINE: Cincinnati No.4 No.: 26 25 cm TLF IIME UI-F 0.25a.n.
Vertical Miller Cutter TIME ON: 9.47
TOOLS AND GAUGES: Fixture F.239 Gauoe 239/7 Surface olate ELAPSED TIME: 38.00
PRODUCT/PART:8.239 Gear Case No.: CHECK TIME: 2.80
NE I
IME:I 35.20
DWG. No.: 8.239/l MATERIAL: Cast lron OBS.TIME: 35.20
to l.S.S.2 UNAUU. I IME:
OUALITY: as dws. WORKING CONDITIONS: U.T.AS %:
mlc I cutter OK: lisht sood STUDIED BY:
OPERATIVE: M/F CLOCK No;1234 CHECKED BY:
Sketch and notes on back of sheet 1
El. No. ELEMENT DESCRIPTION BT F Obs.
Repetitive
A Outside work 0.261 ut t8
B lnside work 0.251 1/1 18
c As card No. 1264 o.122 t/l 18
D 0.186 | /l t8
F Outside work 0.254 t/1 t8
G 0.104 | /l 18

Machine element 0.816 1/l t6

E Unoccupied time within MCT 0.257 | /t t8

Occasional elements and contingencies

Help unload boxes of new castings
and load boxes of finished castinos
to truck 1.100 1 Freg.l /30 castings
(outside work) (Boxes hold l0 castings)

Talk to foreman IOW) (a.m.) 0.400 | /18 ohs.

lnspector checks 3 pieces and
discusses ( a.m. ) 1.020 | /18 obs.
(ow)

Relaxation time (a.m.) 6.120

303
 EXAMPLE OF A TIME STUDY

Figure lO2. Extract from the analysis of studies sheet

As each time study on the operation was worked up and summarised, the entries from the
study summary sheet were transferred to an analysis of studies sheet of the type illustrated in hgure 8 l.
These sheets are often printed on paper ofA,3 or double foolscap size or larger, and so only a portion of
the whole sheet is reproduced opposite.

It will be seen that hve studies were made in alt on this operation, a total of 92 cycles being
observed. The work of three different operatives was studied, by four different studymen. Standard
times for regular machine shop operations are usually compiled from predetermined time standards (see
Chapter 2l), and when a considerable body of data has been built up it is often possible to derive
accurate time standards with fewer studies, or by observing a smaller number of cycles of the operation.

Inspection of the study results for the elements A, B, C, D, F and G indicated normal con-
sistency, with no reading suggesting a need for further investigation. The work of proceeding to the final
selected basic times for the elements was therefore undertaken next. The selection was made by taking
the weighted average for each element. All the repetitive elements were constant elements, so that there
was no need lor graphical presentation. In the flrst ofthe four columns in the block at the right-hand
side of the sheet, the total basic time was entered against each element. Dividing these totals by 92, the
aggregate number of cycles, yielded the figures for basic minutes per occasion, entered in the next
column. These are now shown to the second decimal place only; that is, to the nearest one-hundredth of
a minute.

The third column records the frequency of occurrence per cycle-for all the repetitive ele-
ments l/l-and thus the entries in the last columno which show the basic minutes per cycle, are for this
operation the same as those in the second column of the right-hand block. The unoccupied time, ele-
ment E, has been arrived at in the same manner as the study summary, by deducting the sum of the in-
side work basic minutes from the machine-controlled time. Usually the unoccupied time would not be
evaluated until after relaxation allowance had been added to the work elements, but in this instance, as
is indicated when discussing these allowances on the next page, there was no need for such a refine-
ment.

The occasional element "Help labourer" was observed on three occasions only, in three dif-
ferent studies. Since it is known that the truck carries three boxes each containing ten castings, it is clear
that the frequency with which this element will occur is once every 30 castings, or cycles. The average
basic time per occasion was therefore divided by 30 to yield the basic time per cycle of 0.04 minutes.

"Talk to foreman" was dedt with by dividing the total time observed by the 92 cycles
observed, giving a time of 0.01 minutes per cycle. The "Inspector checks" element was treated simi-
larly, though in this instance as it was learned from the foreman that the inspector's duty was to check
three castings in every 100 the frequency has been taken as l/100. These two very small periods of
time, both entered in actual minutes, were eventually considered to be best dealt with as contingencies
and were covered by the contingency allowance given.

304
 EXAMPLE OF A TIME STUDY

Study No.: 3 o t7 25 28 u
J
Date: 27/4 t/5 4/5 7/5 fi/5 o
Operative: CAA rBN CAA TBN cRw z (J
U)
J o
Clock No.: 1234 t547 1234 1 547 1846 ul
Machine No.: 26 34 26 127 71
F
o
9?
ac) t.r-tL ll,
UJ
F <o Our F
coo
on
\2
Zy
f
2u
urf >oHE
-J

Io-
UI gd oo
LU
u)t
Study taken by: BDM CEP DFS BDM Cycles d= rQ {u
to t- r.r- O co o-
No. of cycles studied: t5 26 t8 t3 20 92
ELEMENT$ BASIC TIME PER OCCASION B.T. B.M. B.M.

PIU casting, locate, lock,

set on o.276 o.257 o.261 0.270 o.281 24.645 o.27 | ll o.27
Hold, break milled edge,
clean o.240 o.266 o.251 0.252 o.244 23.305 o.25 t /t o.25
Gauge o.t 14 o.127 o.t 22 0.128 o.tt1 t 1.o89 o.1 2 | /l 0.1 2

Aside finished part, o.197 o.t 96 o.186 o.1 9t o.t 80 17.485 0.1 I I ll o.19
position new
Wait mlc (actual minutes) o.264 o.222 o.257 o.253 o.275 | /l o.26

Stop m/c, unlock, aside pan o.271 o.270 o.254 o.250 o.245 23.820 o.26 t /l o.26

Clear swarf o.o96 o.tt2 o.t04 o.o90 o.o92 9.240 o.to | lt o.1 0

Machine- controlled time

(actual minutes) o.821 o.81 I o.816 o.824 o.8t o 75.OOO o.82 | /t o.82
Help labourer UIL and load
boxes of castings l.loo 1.420 t.3to 3.830 1.28 | /30 a.o4
(l occ.) (l occ.) (l occ.)

Talk to foreman
(actual minutes) 1.140 o.400 o.870 2.41O 0.80 1 /92 o.ot
I nspector ch ecks. drscuss
(a.m.) t.470 1.o20 1.770 4.260 1.42 | /100 o.o1
ll occ,) ll occ.) (l occ.)

305
 Figure l03. Calculation of relaxation allowance

A form such as that shown in the figure reproduced below is often used for the compilation
of relaxation allowances. It provides a convenient way of ensuring that no item of relaxation allowance
is omitted. The derivation of the allowances is based on the data given in the tables reproduced in
Appendix 3. The total figure for relaxation allowances (which represents both fixed and variable
allowances) has also an added 5 per cent personal needs allowance. By deducting this figure for each
element from the total allowances hgure, one can arrive at fatigue allowances alone.

Since this is an example of restricted work the fatigue allowance has been calculated
separately.

RELAX
PHYSICAL STRAINS
PRODUCT: B. 239 Gear Case
WEIGHT : 6.8 kg each (13'9 lb)

OPERATION: Finish-mill second face (9

-F
=
lrJ
(J
oJ
E uJ o
o J
o ul
tL z tr
ut
(9
UJ
E
o o o
l tr F E
WORKING CONDITIONS: 6ood ar F E F
Lt o E, o o
o
.L
@ I
o llJ
E

El. No. ELEMENT OESCRIPTION Pt8. Strain Pts. Strain Pts. Strain Pts. Srrain hs.

A Pick up casting, locate in fixture, M 8 L 1

lock 2 nuts, set guard, stan

machine

B Break edges with file, and clean L L 1

c Gauge L L 1

D Pick up casting, place in box, M I L 1

pick up new casting and

place near machine

E Wait for machine (unoccupied

time)

F Stop machine. open guard, M 8 L 1

unlock nuts, remove casting,

place on surface plate

G Clean fixture with compressed L 3

air

Occa- Help labourer load and unload H 4A H 12

sional boxes of castings (lO per box
Element : 68 kg/2 men, l/30 cycles)
and
The percentagos of total allowances, as derived from tho points conveEion table in Appsndix 3, cover both basic and variable allowances
1 a

porsonal needs allowance of 5 per cent. 2 Severity of strain: L: low; M : medium; H: high.
 The only period of unoccupied time during the machine-controlled time totalled 0.26 actual
minutes. This was considered to be too short a period for recovery from fatigue (see Chapter 19, section
4), so the whole of the relaxation allowance, both the personal needs part and the fatigue allowance,
was considered as an addition to outside work and was added to the cycle time.

The personal needs allowance of 5 per cent was calculated on the sum ofthe outside work
plus the machine-controlled time. Fatigue allowance was calculated on the work elements only.

It will be seen from flrgure 104 that the total relaxation allowance amounted to 0. I ? minutes.
This is less than the period of unoccupied time (0.26 minutes), but is nevertheless to be added outside
the machine-controlled time as periods of 0.50 minutes or less of unoccupied time are ignored for
fatigue allowance purposes.

)WANCE
STRAINS WORKING CONDITIONS

c
o
o
o
o
to
E o o
.D
o o qrS
ah

c (Jo
f= 6g sh 29.
-ul -O
FO 3'
E o Q_9
z F
z l
F o
tr
z
6
{ti
frz =<
{c
E
F lrl
E
ul Itr o
o-
J
E<
-rB
u.9
=6
@
ul
o a-
zul
u, F
U' F F
t! F <o 96
o f l G,
o FJ
o
ul z u.l
F I o o B F F< -.1
FE

Stmln fts. Slrain hs. itrain Pis. Strain hs. Straln Pts. Stmln Pts. Sirah Pts. Pts.

L 2 L 1 M 6 L 1 21 13 8

L 2 L 1 M 6 L 1 13 11 6

L 2 L 1 M 6 L 1 13 11 6

L 2 L 1 M 6 L 1 A 13 I

L 2 L 1 M 6 L 1 21 13 I

L 1 M 6 L 1 11 11 6

L 1 M t! L 1 68 35 m
 EXAMPLE OF A TIME STUDY

Figure l04' Final calculation of relaxation allowance

The allowance which resulted from applying the percentage hgures built up in hgure 103 is
shown opposite. It will be seen that a contingency allowanc e of 2.5 per cent, inclusive of relaxation, was
included under the heading of outside work, to cover the periods spent in discussions with the foreman
and the inspector.

308
 EXAMPLE OF A TIME STUDY

Fatigue allowance Basic Fatigue Allowance

time per cent. min

Inside work elements: B 0.25 6 0.015

C 0.12 6 0.007
D 0.19 8 0.015

0.56 0.037

Outside work elements: A 0.27 8 0.022

F 0.26 8 0.021
G 0.10 6 0.006
Occasional element help labourer 0.04 30 0.012
Contingency allowance-
2.5 per cent of total basic time,
inclusive of relaxation allowance 0.03

0.70 0.061

Total fatigue allowance 0.098

Personal neds allowance

5 per cent of Outside work plus

machine-controlled time :
5 per cent of(0.70 + 0.82) . 0.076

Total relaxation allowance

Fatigue allowance plus personal needs allowance 0.174

l.e. 0.17 min

309
 EXAMPLE OF A TIME STUDY

Figure lO5. Calculation and issue of the standard time

The method of calculation shown opposite is that appropriate to restricted work. When stan-
dard times for jobs made up wholly of manual elements are compiled, it is common to add the appro-
priate relaxation allowances element by elemen! thus building up standard times for each element,
the sum of which of course represents the standard time for the whole job. In such instances it is usual
to show the final calculations on a job summary sheet which lists the elements in full, with their descrip-
tions, and all relevant details of the job for which the standard time has been built up. This would be
done also for restricted work such as that in t}re present example, though inside and outside work would
be shown separately. It is good practice to add a cycle diagram to the job summary sheet.

The methods adopted to issue-or publish-standard times vary according to the circum-
stances of thework situation. In jobbing shops, and for non-repetitive work (such as much maintenance
work) jobs may be studied while they are in progress and the time standards be issued directly to the
workers concerned, by annotation on the job sheet or other work instruction, after approval by the
shop foreman. When the work is mainly repetitive, with the same operations being performed many
times over, for perhaps weeks or months on end, tables of values, derived after extensive studywork,
may be issued by the work study department.

Figure lO6. Over-all cycle time

The over-all cycle time is of course the same as the standard time. The hnal cycle diagram is
shown opposite.

The use to which time standards may be put is discussed in Chapter 23. It
should be noted that, although the example which has been studied in detail is a simple
one for a manufacturing industry, a very similar procedure is carried out for non-
manufacturing operations or for any other work which is time-studied for the purpose
of setting time standards.

310
 EXAMPLE OF A TIME STUDY

Computation of Standard Time

Outside work 0.70 basic min

Inside work . 0.56 basic min
Relaxation dllowance. 0.17 min
Unoccupied time allowance . 0.26 min

Standard time 1.69 standard min

Alternatively:
Outside work 0.70 basic min
Machine-controlled time 0.82 min
Relaxation allowance. 0.17 min

1.69 standard min

OVER-ALL CYCLE TIME: 1.69 min

c>
96
OG
6>
-(,
OE
co
ooc
'ai
machine-controlled time:0'82 min o'E
t- otr
oo
O(J

-r{ -+-t
t
o9
PE
iE
GO

G-
ot
JC
EDO
'E
-Ed al,

rO_

311
 Predetermined
time standards

1. Definition
Predetermined time standards (PTS) are advanced techniques which aim at
defining the time needed for the performance of various operations by derivation from
pre-set standards of time for various motions and not by direct observation and
measurement. They are not normally considered suitable for the trainee to use until he
has gained a real understanding of and considerable experience in work study prac-
tice. He will also require specialised PTS training. The essential nature of these stan-
dards will be explained in this chapter.

As the definition indicates, PTS systems are techniques for synthesising

operation times from standard time data for basic motions. Synthesis and standard
data are discussed more fully later in this book.
The nature of PTS systems can be easily illustrated by reference to a simple
work cycle, such as putting a washer on a bolt. The operator will reach to the washer,
grasp the washer, move the washer to the bolt, position it on the bolt and release it.
Many operations consist, broadly speaking, of some or all of these five
basic motions. To these are added other body motions and a few other elements.
Table 18 illustrates the components of a basic PTS.
By examining a given operation and identifying the basic motions of which
it is composed, and by referring to PTS tables which indicate standard times for each
type of motion performed under given circumstances, it is possible to derive a stan-
dard time for the operation as a whole. 313
 PREDETERMINED TIME STANDABDS

Table 18. Components of a basic PTS

Dscription

REACH Move hand to destination.

GRASP Secure control of object with fingers.
MOVE Move object.
POSITION Line up and engage objects.
RELEASE Let go of object.
BODY MOTIONS Leg, trunk movements.

2. Origins
The pioneer of motion classification was Frank B. Gilbreth whose
"therblig" of hand or hand and eye motions
(see Chapter 11, section 9) subdivisions
were the key concept in the development of motion study. Two main ideas underlying
Gilbreth's approach were that the act of making a detailed critical analysis of work
methods stimulates ideas for method improvement; and that the evaluation of alter-
native work methods can be achieved by a simple comparison of the number of
motions, the better method being the one requiring fewer motions.
The credit for adding the time dimension to motion study is attributed to
A. B. Segur, who in 1927 stated that'owithin practical limits the time required for all
experts to perform true fundamental motions is a constant".r Segur developed the
first predetermined time standards, calling his system Motion Time Analysis. Little is
known publicly about the system since he exploited it as a management consultant
and bound his clients to secrecy.
The next important development was the work of J. H. Quick and his asso-
ciates, who originated the Work Factor system in 1934. Like Segur's system' this
was exploited on a management consultancy basis and little information was
published about it. However, it was eventually adopted by a large number of com-
panies and is now in active use.
A considerable number and variety of PTS systems were produced during
and following the Second World War. Among these was a system which has become
very widely used throughout the world, Methods-Time Measurement (MTM).
Because of its importance MTM will be used here to illustrate the way in which
predetermined time standards are arrived at.
MTM was first developed by three men working on the system at the
Westinghouse Electric Corporation in the United States: H. B. Maynard, G. J.
Stegemerten and J. L. Schwab. Their findings were published, and thus, for the first
time, full details of a PTS system were made freely available to everyone. MTM has
also set up, in various countries, independent non-profit-making MTM associations to
control the standards of training and practice and to continue research into and the

--- ,A. B. Segur: "Labour costs at the lowest figure", in Manufacturing Industries (New York'
314 Vol.13,1927,p.273.
 PBEDETERMINED TIME STANDARDS

development of MTM. These associations have established an international co-ordi-

nating body, the International MTM Directorate.In 1965, a simplified form of MTM
known as MTM-2 was developed, and this led to a rapid increase in the use of the
system.

3. Advantages of PTS systems

PTS systems offer a number of advantages over stop-watch time study.

With PTS systems one time is indicated for a given motion, irrespective of where such
a motion is performed. In stop-watch time study it is not so much a motion as a se-
quence of motions making up an operation that is timed. Timing by direct observation
and rating can sometimes lead to inconsistency. A PTS system, which avoids both
rating and direct observation, can lead to more consistency in setting standard times.
Since the times for the various operations can be derived from standard-
time tables, it is possible to define the standard time for a given operation even before
production begins, and often while the process is still at the design stage. This is one of
the great advantages of PTS systems, as they allow the work study man to change the
layout and design of the workplace and of the necessary jigs and fxtures in such a
way that the optimum production time is achieved. They also make it possible, even
before starting the operation, to draw up an estimate of the cost of production, and
this could obviously be valuable for estimating and tendering purposes or for
budgeting. PTS systems are not too diflicult to apply and can be less time-consuming
than other methods when time standards for certain operations are being determined.
They are particularly useful for very short repetitive time cycles such as assembly
work in the electronics industry.

4. Criticisms of PTS systems

In view of the value of PTS systems, it is surprising that it took so long for
them to become part of general work study practice. The main reason for this delay is
probably the considerable number and variety of systems that have been produced,
together with the fact that many of them could be obtained only by employing consul-
tants. At present, over 200 such systems exist. This proliferation has led to complaints
from management, trade unions and work study men.
Furthermore, arry PTS system is rather complicated. It is not easy to learn,
and a work study man needs a good deal of practice before he can apply it correctly.
The task of learning enough about the various systems to be able to judge their claims
and their relative merits is an almost impossible one. For example, some systems do
not go into suflicient detail in defining a certain motion. They might, for instance, give
the same time for the movement both of an empty cup and of one full of water, or for
the movement of a dry brush and of one laden with paint, which must be moved with
care. The situation was made more complicated by the lack of freely available infor-
mation on many systems, whose tables were considered to be the property of their
developers and were thus not available for publication. 315
 PREDETERMINED TIME STANDARDS

Some work study researchers also questioned the basic assumptions of PTS
systems. In part these criticisms were justified, although some appear to have arisen
through misinformation or misunderstanding. PTS systems do not, as was claimed,
eliminate the need for the stop-watch, any more than they eliminate method study or
work sampling. Machine time, process time and waiting time are not measurable with
PTS systems, and occasional or incidental elements are often more economically
measured by using other techniques. In fact, it is diffrcult to obtain 100 per cent
coverage in a plant using only a PTS system, and for certain operations such as batch
production or non-repetitive jobs the use of such a system can be an expensive
proposition.
One type of criticism stems from a too literal interpretation of the basic
assumption of Segur, quoted above. In fact, absolute constant times are not implied.
The times indicated in PTS tables are averages, and the limits associated with the
averages ares small enough to be neglected in all practical circumstances.
Another common criticism is that it is invalid to add up times for individual
small motions in the way required by PTS systems because the time taken to perform
a particular motion is influenced by the motions preceding and following it. It is unfair
to criticise the more important PTS systems on these grounds, because not only were
these relationships clearly recognised by their originators but also special provision
was made to ensure that the essential correlations were maintained. In the case of
MTM, for example, this was achieved by establishing subdivisions of the main classes
of motions and by creating special definitions and rules of application to ensure their
essential linking. The relationships are also preserved in simplified systems such as
MTM.2.
It
has also been declared that the direction of the motion influences the
time-for example, that it takes longer io cover the same distance when moving up-
wards than when moving downwards-and that no PTS system isolates this variable.
MTM researchers would agree that the direction of the motion is an important
variable. However, they argue that in a single work cycle the operative will not be
reaching only upwards, nor always away from the body, nor making only anti-clock-
wise turns: he will reach downwards or towards the body or make clockwise turns
also, and sojustify the use ofaverage values.

5. Different forms of PTS systems

The work study man is likely to encounter a number of different forms of

PTS systems, and it will therefore be useful for him to understand the main ways in
which the systems vary. He will find differences as regards levels and scope of applica-
tion of datq motion classification and time units.

DATA LEVELS

Figure 107 illustrates data levels by means of the official international

316 MTM systems: MTM-I, MTM-2 and MTM-3.
 PREDETEBMINED TIME STANDAFDS

Figure 107. PTS data levels: basic motions

1st level 2nd level 3rd level Higher level
(MTM-1) (MTM-2) (MTM.3} (e.9. MTM-V)

Combinations
HANDLE give simple and
complex elements

RELEASE

The first level comprises the motions RELEASE, REACH, GRASP,

MOVE, POSITION, RELEASE At the second level these motions are combined: in
MTM-2, for instance, the motions are GET and PUT. At the third level, the motions
have been further combined as HANDLE, to give a description of the complete work
cycle. Beyond the third level there are as yet no completely clear-cut rules, and
methods of classification vary according to the work area for which the data are
intended.

SCOPE OF APPLICATION OF DATA

PTS systems vary as regards the universality of their application. It is dif-
ficult to explain this concept exactly, but table 19 attempts some clarification.
First of all there are systems of universal application, which cover all work
anywhere. This is so for motion data at the MTM-I, 2 or 3 levels and for the Work
Factor systems. Second, there are data which relate to a main occupation, for exam-
ple office work, maintenance work or some kinds of production work. Examples of
these are Master Clerical Data for the office and MTM-V, the Swedish MTM
Table 19. Scope of application of data

PTS system S@p€ of spplication

I - Universal MTM-I,2,3; Transferable throughout the world and

Work Factor applicable in all manual work areas.

2 - General Master Clerical Data (oflice); Transferable but within a work area.
MTM-V (machine shops)

3 - Specific Standard data for particular Not transferable without validation

departments itr a plant studies.
317
 Association data for machine shops. Finally, there is the least general category: the
specific data systems which are developed for use in particular factories or depart-
ments. These data are not transferable without validation studies.

MOTION CLASSIFICATION
PTS systems provide information about manual work cycles in terms of
basic human motions. There are differences between the criteria adopted for the clas-
sification of these motions. Broadly speaking, there are two main sets:

tr Object-related classification.
tl Behaviour-related classification.

The object-related classification is employed in the majority of PTS systems

(including Work Factor, Dimensional Motion Times and MTM-l) and virtually all the
data systems relating to main occupational groups or specifically designed for use
within a plant. In a object-related system, reference may be made to characteristics of
parts (such as grasping a 6x6 x6 mm object), or to the nature of the surrounding
conditions (such as reaching to an object which is jumbled with other objects, or
reaching to an object which is lying flat against a surface). The classification is,
however, not entirely object-related since motions such as Release Load or Disengage
have behavioural definitions.
Unlike most systems, MTM-2 employs exclusively behavioural concepts.
This is also true of MTM-3, Master Standard Data and a few less well known
systems. The behaviour-related systems classify motions according to what they look
like to an observer: for example, a movement of the empty hand for a distance of
between 5 and 15 cm followed by a grasping action madeby a simple closing of the
fingers defines the GEZmotion in the MTM-2 system (see below).

TIME UNITS
No two PTS systems have the same set of time values. This is partly due to
the fact that different systems have different motion classes and the time data there-
fore refer to different things. Again, the choice of the basic unit (fractions of a second,
minutes, hour) may vary, and some systems follow the practice of adding contingency
allowances to motion times, whereas others do not. A final major cause of variations
arises from the differences in the performance level implied in the time data. The
methods adopted for standardising, normalising or averaging the motion times are not
uniform. Consequently, PTS time data are divided into one of two sets: high- or low-
task time systems, also understood as day work or incentive level time systems. Work
Factor systems are high-task systems and express their data in minutes. In contrast,
the MTM systems are expressed in time measurement units (tmu) which represent one
hundred-thousandth of an hour, or about one twenty-eight of a second. The MTM
time values, which were derived mainly from film analysis of a variety of industrial
operations (the method was to count the number of "frames" occupied by each
motion), were standardised using the well-known ooWestinghouse" or ool-evelling" sys-
tem and therefore are low-task systems.'The times are stated to be those which are
achieved by an experienced operative of average skill, working with average effort and
318 consistency under average conditions. The performance level, MTM 100, is therefore
 PRED

somewhat less than BSI 100. A public statement on this by the United Kingdom
Institute of Work Study Practitioners and the MTM Association suggests that
MTM 100 equals BSI 83.1

OTHER CONSIDERATIONS
Some important properties of PTS systems are much less easy to establish
and to compare than the aspects discussed in the previous subsections. Examples of
these are the precision and accuracy of the time data, speed of application, methods
description capability, and learning time. The lack of reliable, detailed information
and, to some extent, the lack of agreed design criteria hamper comparison of these
properties.

6. Use of PTS systems

The system most likely to be used by the work study man is MTM-2. The
following categories constitute the MTM-2 system. Each will be explained in
detail in the following subsection.

Category Code

GET GA
GB
GC
PUT PA
PB
PC
REGRASP R
APPLY PRESSUR,E A
EYE ACTION E
FOOT MOTION F
STEP S
BEND AND ARISE B
WEIGHT FACTORS GW
PW
CRANK C

The MTM-2 system provides 39 time standards ranging from I to 61 tmu.

These are shown on the data card reproduced in table 20. As stated above, one tmu
equals one hundred-thousandth of an hour.

t "MTM and the BSI rating scale", n Work Study and Management Semices (London), Feb. 1969'
p.s1. 31 9
 PREDETERMINED TIME STANDARDS

Table 20. MTM-2 data card

Time in tmu

PA

t4 3 l0 2l
-5 3 7
6 t0 l9 6 l5 26
-15
-30 9 t4 23 ll l9 30
r3 l8 27 l5 24 36
-45
t7 23 32 20 30 4t
-80
GW:lperlkg PW:lper5kg

ARE SF B

146'l 189 61

Warning: Do not attempt to use these data unless you have been trained and qualified under a scheme approved
by the International MTM Directorate.

MTM-2 CATEGORIES
tr GEr (G)
GET is an action with the predominant purpose of reaching with the hand
or fingers to an object, grasping the object and subsequently releasing it.
The scope of GET stalts: with reaching to the object;
includes: reaching to, gaining control and subsequently
releasing control ofthe object;
ends: when the object is released.
Selection of a GET is done by considering three variables:
(l) case of GEI-distinguished by the grasping action employed;
(2) distance reached;
(3) weight of the object or its resistance to motion.
Cases of GET are judged by the following decision model:

Is it enough
to close hand
or fingers with
one motion?

320
 An example of GA is putting the palm of the hand on the side of a box in
order to push it across a table.
An example of GB is getting an easy-to-handle object, such as a one-inch
cube, which is lying by itself.
An example of GC is getting the corner of a page of this book in order to
turn it over.
Distance is a principal variable n
GET, and five distance classes are
provided. Distances are judged by the upper limits of the classes, which are 5, 15, 30,
45 and over 45 cm. The code 80 is assigned to the highest class. Distances are esti-
mated from the path of travel of the hand, less any body assistance.

0.0 5.0 -5
5.0 15.0 -15
15.0 30.0 -30
30.0 4s.0 -45
4s.0 -80

D GET WETGHT(GW)
GET WEIGHI is the action required for the muscles of the hand and arm
to take up the weight of the object.

The scope of GET WEIGHT starts: with the grasp on the object com-
pleted;
includes: muscular force necessary to gain
full control of the weight of the
object;
ends: when the object is sufliciently
under control to permit movement
ofthe object.

GET WEIGHI occurs after the fingers have closed on the object in the
preceding GET.lt must be accomplished before any actual movement can take place.
When the weight or resistance is less thar. 2 kg per hand, no GW is assigned. When
resistance exceeds Zkg,l tmu is assigned for every kg including the first rwo.

E PUr@\
PW is an action with the predominant purpose of moving an object to a
destination with the hand or fingers. 321
 PREDETERMINED TIME STANDARDS

The scope of PUT starts: with an object grasped and under control at
the initial place;
includes: all transporting and correcting motions
necessary to place an object;
ends: with object still under control at the intended
place.

Selection of a PW is done by considering three variables:

(1) case of PUT-distinguished by the correcting motions employed;

(2) distance moved;
(3) weight of the object or its resistance to motion.

Cases of PUT are judged by the following decision model:

Isita Are there

continuously obvious
smooth correcting
motion? motions?

An example of PA is tossing aside an object.

An example of PB is the action of putting a 12 mm ball in a 15 mm
diameter hole.
An example of PC is inserting a Yale or similar key in a lock.
A correction is not likely to be confused with a short PA. A correction is a
very short unintentional motion at the terminal point; a PA is purposive, usually of
easily discernible length.
The motion distance is handled in a similar manner to GET.
When there is an engagement of parts following a correction, an additional
Plllwtll be allowed when the distance exceeds 2,5 cm.

tr PW WETGHT (PW)
PUT WEIGHT"is an addition to a PW motion depending on the weight of
322 the object moved.
 PREDETERMINED TIME STANDARDS

The scope of PUT WEIGHT starts: when the move begins;

includes: the additional time, over and
above the move time in PUT, to
compensate for the differences in
time required in moving heavy
and light objects over the same
distance;
ends: when the move ends.

PW is assigned when resistance to movement exceeds 2 kg per hand.

Weights are calculated as in GET WEIGHL Between 2 kg and 5 kg, I tmu is allowed
and coded PW5; between 5 kg and l0kg2 tmu are allowed and coded PWl0; and so
on.

tr REGRISP (R)
REGRASP is a hand action with the purpose of changing the grasp on an
object.

The scope of REGRASP starts: with the object in the hand;

ends: with the object in a new location in the
hand.
A single REGRASP consists of not more than three fractional movements.
Digital and muscular readjustments, while performing an APPLY PR,E,S-
SURE, are included in APPLY PR.ESSUXE. A REGRASP should not be assigned in
combination with A P P LY P RE S S URE.
If the hand relinquishes control and then secures another grasp on the ob-
ject aGET,notaREGRASP.
the action will be
An example of R is changing the grasp on a pencil in order to get into the
position for writing.

tr APPLY PR.ESSURE (A)

APPLY PXESST/R.E is an action with the purpose of exerting muscular
force on an object.

The scope of APPLY PR.E^S^SURE starts: with the body member in

contact with the object;
includes: the application of controlled
increasing muscular force, a
minimum reaction time to
permit the reversal of force
and the subsequent releasing
of muscular force;
ends: with the body member in
contact with the objecl but
with muscular force released. 323
 PREDETEFMINED TIME STANDARDS

The minimum dwell time covers mental reaction time only. Longer dwells,
in holding actions, must be separately evaluated.
APPLY PR^E,SSURE applies to the action of exerting muscular force on an
object to achieve control, to restrain or to overcome resistance to motion. The object
is not displaced more than 6 mm during the action of APPLY PRE^S^SURE.
APPLY PRESST/RE, which can be performed by any body member, is
recognised by a noticeable hesitation while force is applied. It consists of three com-
ponents:

(1) the application of controlled increasing muscular force;

(2) a minimum reaction time to permit the reversal of force;
(3) the release of muscular force.

An example of A is the final tightening action made with a screwdriver or

spanner.

tr EYE ACTTON(E)
EYE ACTION is an action with the purpose of
either: recognising a readily distinguishable characteristic ofan object;
or: shifting the aim of the axis of vision to a new viewing area.

The scope of EYE ACTION starts: when other actions must cease be-
cause a characteristic of an object
must be recognised;
includes:
either: muscular readjustment of the lens
of the eyes and the mental Pro-
cesses required to recognise a dis-
tinguishable characteristic of an
object;
or: the eye motion performed to shift
the aim of the axis of vision to a
new viewing area;
ends: when other actions can start again.

A single eye focus covers an arca 10 cm in diameter at 40 cm from the

eyes. Recognition time included is suffrcient only for simple binary decision.
An example of E is the action of determining whether a coin is showing
head or tail.

tr FOOT MOTION (F)

FOOT MOTION is a short foot or leg motion when the purpose is not to
324 move the body.
 PREDETERMINED TIME STANDARDS

The scope of FOOT MOTION starts: with the foot or leg at rest;
includes: a motion not exceeding 30 cm
that is pivoted at the hip, knee
or instep;
ends: with the foot in a new location.
FOOT MOTION is judged by the decision model for FOOT MOTION
and STEP.

tr srEP (s)
STEP is
either: a leg motion with the purpose of moving the body;
or: a leg motion longer than 30 cm.

The scope of STEP startsi with the leg at rest;

includes:
either: a motion of the leg where the purpose is to
achieve displacement of the trunk;
or: a leg motion longer than 30 cm;
ends: with the leg at a new location.

STEP or FOOT MOTION is judged by the following decision model:

Is the purpose of
Is the leg
the motion to
motion longer
achieve displacement
than 30 cm?
of the trunk?

To evaluate walking, count the number of times the foot hits the floor.
An example of F is depressing a foot pedal in a car.
An example of S is making a single step to the side to enable the arm to
reach further.

tl BEND AND AR(SE(B)

BEND AND ARISE is a lowering of the trunk followed by a rise. 325
 PREDETERMINED TIME STANDARDS

The scope of BEND AND ARISE starts: with motion of the trunk
forward from an upright
posture;
includes: movement of the trunk and
other body members to
achieve a vertical change of
body position to permit the
hands to reach down to or
below the knees and the sub-
sequent arise from this posi-
tion;
ends: with the body in an upright
posture.

The criterion for BEND AND ARISE is whether the operative is able to
reach to below the knees, not whether he actually does so.
Kneeling on both knees should be analysed as 28.

E CRANK (C)
CRANK is a motion with the purpose of moving an object in a circular path
of more than half a revolution with the hand or finger.

The scope of CRANK starts: with the hand on the object;

includes: all transporting motions necessary to
move an object in a circular path;
ends: with the hand on the object when one
revolution is completed.

There are two variables to consider in applying the CRANK motion:

(1) the number of revolutions;

(2) weight or resistance.
The time value of 15 tmu per revolution may be used for any crank
diameter and applies to both continuous and intermittent cranking. CRANK applies to
motions in a circular path whether or not the axis of cranking is perpendicular to the
plane of rotation.
The number of revolutions should be rounded to the nearest whole number.
The weight or resistance influences the time for moving an object. The rules
of adding GW and PW to PUT monons also apply to CRANK. PW applies to each
revolution, whether continuous or intermittent. GW is applied once only to a con-
tinuous series of revolutions, but to each revolution where these are intermittent.
No correcting motions as applied to PW are included in CRANK.If cor-
recting motions occur in putting the object at the intended place an extra PU?"must be
allowed.
326 An example of C is turning a hand wheel through one revolution.
 PREDETERMINED TIME STANDARDS

TRAINING REOUIREMENTS
In the preceding subsection the essentials of the MTM-2 system were out-
lined. To obtain an adequate understanding of the system, however, a trainee will re-
quire at least two weeks of formal training in MTM-2 theory and practice, followed by
guided application on the shop floor with an MTM instructor. A trainee who is
already competent in work study practice should reach a reasonable standard in the
use of MTM-2 after about a month of guided application. MTM-I will require a
longer training period. It is helpful if part of this training can be carried out in a plant
where MTM standards are already in use. When a trainee finds that his own analyses
compare closely with established standards his confidence is rapidly built up. Without
guidance it is very difficult for a trainee to learn how to use MTM adequately.

7. Application of PTS systems

PTS systems can be applied in two main ways:

(l) direct observation of the motions used by the operative;

(2) mental visualisation of the motions needed to accomplish a new or alternative
work method.
The over-all approach adopted when one of the PTS systems, such as
MTM-2, is used for direct observation is not very different from that adopted for mak-
ing a time study (see Chapter 16, especially page2} ).Indeed, a person experienced
in the procedures described in that chapter-selecting the job, approach to the
worker, recording job information, breakdown into elements, allowances, compiling
total job times-is well equipped to become a good PTS practitioner. The main dif-
ference in the approach is that at the point in the total time study procedure where the
observer is ready to time and rate the work cycle, he will instead make an MTM-2
analysis and then enter the motion times on his analysis sheet from the MTM-2 data
card. The calculation of allowances, completion of the documentation and issuing of
the job times are then done in much the same way as in a time study. If the same type
of summary sheets can be used, so much the better. The study summary sheet shown
as figure 80 (page 2IA afi the short cycle study form (figures 78 and 79,pp- 213 and
214) canbe adapted to summarise the information from the MTM-2 analysis sheets.

CHOOSING THE OPERATIVE

In the choice of operative to be observed, it is just as desirable to have a co-
operative, good-average worker for PTS analysis as it is for time study. Exceptionally
fast or abnormally slow performances are diffrcult for time study men to rate, and
they present problems for PTS analysts too. The super-skilled operative combines and
overlaps motions in a manner beyond the capabilities of the average worker, while an
abnormally slow or reluctant operative will make separate, one-handed, hesitant
motions which the average operative will perform smoothly and simultaneously. The
rules and motion combination tables of the MTM system, like those of other systems
such as Work Factor, do provide information for adjusting the observed motion pat-
tern to that applicable to the good-average worker; this additional work can, however, 327
 PHEDETEBMINED TIME STANDARDS

be avoided by an intelligent choice of operative in the first place. Of course, the very
experienced PTS analyst may also study extreme performances with advantage. The
performance of an exceptionally fast operative may give clues as to how all operatives
might be trained to reach a higher-than-average performance level, and the study of
slow operatives would show where diffrculties are being encountered and whether
further training might eliminate these.
RECORDING JOB INFORMATION
In recording job information, it is important to remember that distance is a
significant variable in PTS systems. The plans for the workplace layout should
therefore be accurately drawn to scale. This will help in judging or checking the length
of motions shown in the analyses.

BREAKDOWN INTO ELEMENTS

In PTS systems the division of the operation into work elements follows the
same principles as for time study. The breakdown can be made very much finer, if re-
quired, because the difliculty of timing short elements does not arise. If necessary, the
break points can also be changed easily and without having to retime the cycle. This
flexibility is illustrated in table 21, which shows a very common work cycle-that of
fitting a nut and washer on a stud. For example, if a change of method eliminates the
need for a washer, the appropriate motions (GC30, PC30, PA5) and time (56 tmu)
can easily be removed from the analysis. Finger turns can also be readily separated
from spanner turns and, indeed, from the fitting actions and subsequent turns.

Table 21. Fitting a nut and washer on a stud

Description

Fit washer. 23 GC30 Washer.

30 PC30 To stud.
J PA5 On stud.

Fit nut and turn down by hand. l0 GB15 NuL

26 PC 15 To stud.
6 2PA5 Engage tlreads.
42 6GB5
Turn down nut.
l8 6PA5

Tighten nut using spanner. 23 GB30 Spanner.

30 PC3O To nut"
6 PAI5 Turn nut.
t4 A Tighten.
231

ALLOWANCES AND JOB TIMES

There is no problem of rating with a PTS system such as MTM-2, since the
times have been rated once and for all. All that needs to be done is to add up the
motion times and transfer the totals to the study summary sheet. If times are to be
328 issued at BSI 100 and not MTM 100, the tmu total from the study summary sheet
should be multiplied by 0.83. (This means that, if time. *",.;;ffi;.;.*,
the total tmu can be divided by 2,000.) It should be understood that the general
relationship between the scales applies only to the time totals, and most definitely not
to the individual motion times shown on the MTM data cards. Converting individual
motion times is quite improper since these are not improved uniformly when a higher
performance of a cycle time is achieved.
The times for low control motions (such as GA and PA) are improved only
a little compared with those for the highly complex motions (such as GC and PC).
The issue is, however, more complicated than this because one would also need a dif-
ferent set of motion combinations when considering a different performance level.
Sophisticated MTM users, such as those in the Scandinavian countries, prefer to issue
values at MTM 100.
Relaxation and other allowances are added in exactly the same way as for
time study, in order to give the total job time.
VISUALISATION
When the work study man does not have the opportunity of observing the
work cycle, for example when he is designing a new work method or constructing
alternative methods during method study of an existing job, he must mentally visualise
the motions needed. Figures 108 and 109 given an example of a PTS problem which
can be solved by visualisation of the various motions involved, as can be seen from
figure I10.
The ability to visualise motion patterns depends on the studyman's intel-
ligence and on his practical experience. The more familiar he is with work study, the
more readily he can picture in his mind the motions necessary to pick up and fit parts
together, as well as visualising which motions can be performed together easily and
which motions are diffrcult to carry out simultaneously.
In designing work methods, it can be helpful to use a methods laboratory
(see Chapter 11, section 14). However, when motion analysis is undertaken there is a
need for caution, just as there is with time standards. The experiments with new
methods will probably be performed by the work study man himself or by his col-
leagues, and it is important that they should bear in mind that their own performances
will generally fall far short of those which will be achieved by the regular shop floor
operatives. Even where a shop floor operative is assisting in the methods laboratory,
his performance of a new work cycle will fall short of the standard he will achieve
when he has had suffrcient practice in working the cycle under shop floor conditions.
In both these instances the rules for work design, particularly those of the
motion combination possibilities expected of the average experienced operative, must
be used to arrive at a correct shop floor method.
It is in the work design process that a work study man who chooses to use
an MTM-2 system, for example, will reap the benefit of a full training in the detailed
MTM-I system on which MTM-2 was founded. However, at the very minimum he
must understand the classification details of MTM-I, the basic motions which make
up the MTM-2 motions and the rules covering the motion combination possibilities of
the basic motions, particularly in relation to practice opportunity, area of normal
vision and difficulty of handling. With this knowledge he will know, for example, that 329
 Figure lO8. Base assembly

MEASUREMENTS
IN MILLIMETRES

PIN
I
s

10 DEEP

\ _iro

330
 PREDETERMINED TIME STANDAHDS

Figure lO9. Base assembly workplace layout

if he designs the workplace for the parts to be kept in tote pans, this will require a
separate GC with either hand. He will know that even expert operatives cannot per-
form these motions simultaneously, because each motion involves a kind of minute
searching and selecting activity, because the objects are jumbled together. Similarly,
he will know that putting loose-fitting round plugs into round holes can be done with
both hands simultaneously, provided that he has designed the workplace so that the
targets are within the area of normal vision as defined above under EYE ACTION.
The rules provide many such guidelines.

PTS SYSTEMS AND THE BROADER TECHNIOUES

The nature and value of PTS systems should now be reasonably clear. If a
work study man intends to become a specialist, for example in MTM, he will need full
training in MTM-I and MTM-2 and in all the advanced techniques outlined in this
book. In the more general case, where he will probably undertake both work study
and other jobs as well (such as production planning and control-a common com-
bination in small plants, particularly in the developing countries), an MTM-2 training
may be sufficient.
However, it is most important that the studyman should not lose sight of the
fact that the PTS technique is a fine precision tool. Before getting down to minute
detail, he should first have seen what can bq accomplished by using the broader,
simpler approaches. In companies where work study practice has not yet been in-
troduced, intelligent broad thinking will usually reveal ways of bringing about con-
siderable initial improvements in productivity. 331
 Figure 7lO. MTM-2 analysis sheet, base assembly

JOB DESCRIPTION: REF.:

Assemble base SHEET No. 1 ol 1

(see sketches of parts and layout) ANALYST:

DATE:
LEFT-HAND DESCRIPTION LH TMU RH RIGHT.HAND DESCRIPTION

Get base from box GC30 23 tz:-l n"r r,, rrom box
t4 GC5 I
Put base on bench tffid1 30 PC30 Locate pin to base
Get block from box GC30 23 lzi:l G"trtrato. bo,
t4 GC5 I
Move block stud t-7=] 30 PC30 Locate stud throuoh block
Assist location rEl 26 PCt 5 Fit assembly to base
23 GC30 Get connectorfrom box
Assist location t?-=r 30 PC30 Locdte to stud
Locate to pin PC5 2t
Pick up assembly GBI 5 to
Place on conveyor PASO 2A
264

332
 PREDETERMINED TIME STANDARDS

Table 22. Methods-Time Measurement application data in tmu

(Based metric weights and measures)

OFFICIAL INTERNATIONAL MTM.1 DATA

@ INTERNATIONAL MTM DIRECTOBATE
AND
MTM ASSOCIATION FOR
STANDARDS AND RESEARCH
Tables reproduced by kind permission of the lnternational MTM Directorate.

TABLE I_REACH-R

Time (tmu) Hand in motion

Distance Case and description
(cm)
B
Cor E A B
D

2 or Iess 2.0 2.0 2.0 2.0 1.6 1.6

A Reach to object in fixed
4 3.4 3.4 5.1 3.2 3.0 2.4 location, or to object in
6 4.5 4.5 6.5 4.4 3.9 3.1 other hand or on which
8 5.5 5.5 7.5 5.5 4.6 3.7 other hand rests.
l0 6.1 6.3 8.4 6.8 4.9 4.3

t2 6.4 7.4 9.1 7.3 5.2 4.8

B Reach to single object in
t4 6.8 8.2 9.7 7.8 5.5 5.4 location which may vary
t6 7.1 8.8 r0.3 8.2 5.8 5.9 slightly from cycle to
l8 7.5 9.4 10.8 8.7 6.1 6.5 cycle.
20 7.8 10.0 n.4 9.2 6.5 7.1

?2 8.t 10.5 1.9 9.7 6.8 7.7

u ll.l l0:2
C Reach to object jumbled
8.5 2.5 7.t 8.2
with other objects in a
26 8.8 tt.7 3.0 10.7 7.4 8.8 group so that search and
28 9.2 12.2 3.6 n.2 7.7 9.4 select occur.
30 9.5 12.8 4.1 tt.7 8.0 9.9

35 10.4 t4.2 15.5 12.9 8.8 tt.4

q I 1.3 15.6 r6.8 t4.t 9.6 t2.8 D Reach to a very small object
45 t2.l t7.0 18.2 15.3 10.4 t4.2 or where accurate gasp is
50 13.0 18.4 19.6 16.5 tt.2 15.7
required.
55 t3.9 19.8 20.9 17.8 12.0 t7.l

60 t4.7 21.2 22.3 19.0 12.8 18.5

E Reach to indefinite location
65 15.6 22.6 23.6 20.2 13.5 t9.9 to get hand in position for
70 16.5 u.t 2s.0 21.4 14.3 2r.4 body balance or next
75 17.3 25.5 26.4 22.6 15. I 22.8 motion or out of way.
80 18.2 26.9 27.7 23.9 15.9 24.2

333
 PREDETERMINED TIME STANOARDS

TABLE II- MOVE _ M

Time (tmu) Wt allowance

Distance
(cm) Hand Static Dvn- Case and description
in wt con- amlc
motion (ke) stant fac-
A B C B up to (tmu) tor

2 or less 2.0 2.0 2.0 t.7 I 0 1.00

4 3.r 4.0 4.5 2.8
6 4.1 5.0 5.8 3.1
2 1.6 1.04
8 5.1 5.9 6.9 3.7
A Move object against
t0 6.0 6.8 7.9 4.3 stop or to other hand.
4 2.8 t.07
12 6.9 7.7 8.8 4.9
t4 7.7 8.5 9.8 5.4
6 4-3 t-12
t6 8.3 9.2 10.5 6.0
18 9.0 9.8 ll.l 6.5
20 9.6 10.5 tt.7 7.1 8 5.8 t.t7

22 t0.2 tt.2 2.4 7.6

l0 7.3 t.?2
24 10.8 I1.8 3.0 8.2 B Move object to
26 I 1.5 12.3 3.7 8.7 approximate or inde-
28 t2.l 12.8 4.4 9.3 finite location.
12 8.8 t.27
30 t2.7 13.3 5.1 9.8

t4 10.4 t"32
35 t4.3 14.5 16.8 1.2
q 15.8 15.5 18.5 2.6
45 t7.4 r6.8 20.1 4.0 l6 I1.9 1.36
50 19.0 18.0 2t.8 5.4
55 20.5 t9,2 23.5 6.8
l8 t3.4 t.4t
C Move object to exact
60 22.t ?t.4 25.2 t8.2 Iocation.
65 23.6 2t.6 26.9 19.5 20 14.9 t.4
70 25.2 22.8 28.6 20.9
75 26.7 24.0 30.3 ?2.3
22 t6.4 t.5l
80 28.3 25.2 32.0 23.7

TABLE IIIA-TURN _T

Time (tmu) for degees tumed

Weight
30' 75" 105' t2n 135' 150" r65. 180"

Small Otolkg 2.8 3.5 4.1 4.8 5.4 6.1 6.8 7.4 8.1 8.7 9.4

Medium ltoskg 4.4 5.5 6.5 7.5 8.5 9.6 10.6 I1.6 12.7 13.7 14.8

Large 5.1 to 16 kg 8.4 10.5 12.3 14.4 16.2 18.3 20.4 22.2 24.3 26.1 28.2
334
 PBEDETERMINED TIME STANDARDS

TABLE IIIB - APPLY PRESSURE - AP

Fully cycle Components

Symbol Imu Description Symbol tmu Dccription

APA 10.6 AF+DM+RLF AF 3.4 Apply force

DM 4.2 Dwell, minimum
APB 16.2 APA+G2 RLF 3.0 Release force

TABLE IV - GRASP _ G

Case
Time Description
(tmu)

IA 2.0 Pick Up Grasp-Smallo medium or large object by itself, easily grasped.

IB 3.5 Very small object or object lying close against a flat surface.

lcl 7.3 Interference with grasp on bottom and one side of nearly cylindrical object.
Diameter larger than 12 mm.

tcz 8.7 Interference with grasp on bottom and one side of nearly cylindrical object.
Diameter 6 to 12 mm.

lc3 10.8 Interference with grasp on bottom and one side of nearly cylindrical object.
Diameter less than 6 mm.

2 5.6 Regrasp.

3 5.6 Transfer Grasp.

4A 7.3 Object jumbled with other objects so search and select occur.
Larger than 25x25 x25 mm.

4B 9.1 Object jumbled with other objects so search and select occur.
6x6x3 mm. to 25x25 x25 mm.
rc, t2.9 Object jumbted with other objects so search and select occur.
Smaller than 6x6x3 mm.

5 0 Contact, sliding or hook grasp.

335
 PREDETERMINED TIME STANDARDS

TABLEV-POSITION*_P
Class of fit Synmetry Easy to handle Dfficult to handle

S 5.6 tt.2

I Loose No pressure required SS 9.1 t4.7

NS 10.4 16.0

S 16.2 21.8

2 Close Light pressure required SS 19.7 25.3

NS 21.0 26.6

S 43.0 48.6

3 Exact Heavy pressure required SS 46.5 52.1

NS 47.8 53.4
t Distance moved to engage-max. 25 mm.

TABLE VI _ RELEASE _ RL TABLE VII _ DISENGAGE _ D

Time
Case (tmu) Description Easy Difficult
Clm of fit to to
handle handle
I 2.0 Normal release
performed by opening I Loose-Very slight 4.0 5.7
fingers as independent effort, blends
motion. with subsequent
move.
2 0 Contact release
2 Close-Normal 7.5 I 1.8
effort, slight
recoil.

3 Tight-Consider-
able effort, hand
22.9 34.7
recoils markedly.

TABLE VIII _ EYE TRAVEL AND EYE FOCUS _ ET AND EF

Eye travel time: f S.Z ><

$ tmu, with a maximum value of 20 tmu.
where T : the distance between points from and to which the eye travels.
D: the perpendicular distance from the eye to the line of travel T.
Eye focus time : 7.3 tmu.
336
 PBEDETERMINED TIME STANDARDS

TABLE IX_ BODY, LEG AND FOOT MOTIONS

Description Symbol Distance Time (tmu)

Foot motion-Hinged at ankle. FM Up to l0 cm. 8.5

With heavy pressure. FMP l9.l
Leg or foreleg motion. LM. Up to 15 cm. 7.t
Each add'l cm. 0.5

Sidestep-Case I - Complete when leading SS.CI Less than 30 cm. Use REACH or
leg contacts floor. MOVE time
30 cm 17.0
Each add'l cm. 0.2
Case 2 - Lagging leg must contact SS-C2 Up to 30 cm 34.1
floor before next motion Each add'l cm. 0.4
can be made.

Bend, stoop, or kneel on one knee. B.S. KOK 29.0

Arise. .B.AS. AKOI 3t.9
Kneel on floor-Both knees. KBK 69.4
Arise. AKBK 76.7

sit. SIT 34.7

Stand from sitting position. STD 43.4
Turn body 45 to 90 degrees-
Case I - Complete wheri leading leg TBCI 18.6
contacts floor.
Case 2 - Lagging leg must contact TBC2 37.2
floor before next motion can
be made.

Walk. w-M Per metre 17.4

Walk. w-P Per pace 15.0
Walk-Obstructed. w-Po t7.o

OFFICIAL INTERNATIONAL MTM-3 DATA

@ IruTTNruATIONAL MTM DIRECTORATE

CODE HA HB TA TB

-15 t8 34 72t
-80 34 48 16 29

SF 18 B6l
337
 TABLE X - SIMULTANEOUS MOTIONS

MOTION

REACH

MOVE

GlA, G2, C5
GlB, GIC GRASP

POSITION
PINS, P2SS, P2NS
DIE, DlD
DISENGAGE

[ = resv to perform simultaneousty'

=ca. be performed simultaneously with PRACTICE.

f
[ =olfftcur-r to perform simultaneously even after long practice. Allow both times.
MOTIONS NOT INCLUDED IN ABOVE TABLE: TURN-Normally EASY with all motions except when
TURN iS CONtTOIIEd Or With DISENGAGE.
APPLY PRESSUnT \ rUay be EASY, PRACTICE, or DIFFICULT.
CRANK I Each case must be analysed.
POSITION-CIass 3-Always DIFFICULT. DISENGAGE-CIass 3-Normally DIFFICULT. RELEASE-
Always EASY. DISENGAGE-Any classmay be DIFFICULT if care must be exercised to avoid injury or damage
to object.
I
"f==y;*H: I tne area of normal vision. i.e.: E$"#, '"5=BlFLSrLTtf n*r,"

OFFICIAL INTERNATIONAL MTM-z DATA

G) INTERNATIONAL MTM DIRECTORATE

CODE GA GB GC PA PB PC

-5 3 7 t4 3 l0 2t
-15 6 l0 l9 6 l5 26
-30 9 t4 23 ll t9 30
45 l3 18 27 l5 24 36
-80 17 23 3' 20 30 4l
CW:lperlkg PW:lper5kg

A R E s F B
t4 6 7 l8 9 6l
338
 W
Standard data

Many operafions in a given plant have several common elements. The ele-
ment'owalking", for example, is a component of many different jobs. Diverse activities
such as painting, handling or working on a site invariably involve an element of
"walking". When these activities are timed, the same common element is in fact timed
again and again. The job of a work study man would therefore be made much easier if
he had at his disposal a set of data from which he could readily derive standard times
for these common work elements without necessarily going into the process of timing
each one. If, for instance, a standard time could be derived for the particular element
"walking" and could be read directly from a table, this would not only reduce effort
and cost but also lead to greater consistency in time estimations.
One can therefore see that there is an advantage in building up a standard
data bank for various elements which occur repeatedly at the workplace. If such data
existed for a wide range of elements and were reliable, there would be no need to carry
out a time study for a new job. Instead, by breaking down the job into elements and
referring to the data bank to derive the normal times for each element, one could
calculate the total time needed to perform this new job and determine its standard time
by adding the appropriate allowances in the usual way.

1. Majorconsiderations
It is, however, diflicult to visualise a situation where all the possible ele-
ments making up any and every job could be timed and stored for future retrieval. We
may therefore conclude that in practice it is better to restrict the number of jobs for
which standard data are derived-normally to one or more departments in a plant, or
to all the processes involved in manufacturing a certain product. In this way the
coverage becomes more manageable.
The reliability of the data can be increased if as many common elements as
possible that are performed in the same way are grouped together for analysis, and if a
suffrcient amount of accumulated or collected data on each element has been analysed
by a trained studyman.
Reliability can be further increased by making sure that all the factors
affecting a certain element have been taken into consideration. For example, the time
taken to move a sheet of a given size will vary depending on whether it is a solid sheet
 STANDABD DATA

(of metal, for instance) or a malleable one (of rubber, for instance). The weight will
also be an important factor. The time taken to move an iron sheet will be different
from the time taken to move one of foam or cardboard. Again, the thickness will
affect the timing in each case. Consequently, the desciiption of the element must be
as precise as possible and the various factors affecting the timing (in this case, nature
of material, thickness and weight) will also have to be indicated.
Another basic consideration concerns the source of the time data. Should
this be observed time based on stop-watch readings (what might be called "macro-
scopic" (timing systems) or "microscopic" systems such as predetermined time stan-
dards? The first alternative may be more acceptable to the factory personnel in
certain cases, and is sometimes cheaper. However, for certain elements it is not always
possible to have-on record enough readings to enable reliable data to be derived.
Several months or even a year or more may elapse before sufficient data are accu-
mulated in this way. The choice of a microscopic system such as MTM may make
for better coverage, but its use also depends on whether suffrcient experience has been
acquired in using the system and on its applicability. Even in this case, one has to
decide whether to use detailed systems such as MTM-I (which can be more precise
but are expensive) or MTM-2 or MTM-3 (which are less expensive but less precise).
Again, standard data have to be built up with due regard to users'needs.
They are indeed invaluable for a variety of purposes, among them production o'level plan-
ning, cost estimation, incentive payments and budgetary control. However, the
of confidence" in the developed data base which can be tolerated by those who use
standard data for these purposes varies considerably: for example, the requirements
for production planning allow for much greater potential deviation in the standards
than the requirements for individual bonus schemes. Since one cannot produce a dif-
ferent set of data for each user, it is necessary to build a data system that produces the
maximum benefit for each user at the same time.

2. DeveloPing the standard data

The following steps should be taken to develop standard data:

l. Decide on covefage. As indicated above, the coverage should be

restricted to one or more departments or work areas or to'a limited range of
processes
within a plant (for exampli thot. involved in manufacturing a specific product) in
which several similar elements, performed by the same method, are involved in carry-
ing out the jobs.
2. Break the jobs into elements, through job analysis. In this case try to
identify as many elements as possible that are common to the various jobs. Let us as-
sume, for example, that we have a worker in a fruit-packing plant who works at the
end of the operation and whose job is to remove a carton of fruit from a conveyor
belt, stencil tLe name of the customer on the carton and carry it to a nearby skid. Such
an operation may be broken down into elements in various ways, but if the studyman
procleds as indicated below he may find that several of the component elements also
340 occur elsewhere in the plant. The suggested breakdown is-
 STANDARD DATA

(a) hftingthe carton from the conveyor and positioning it on the table;
(b) positioning a stencil on the carton;
(c) applying a 10 cm brush and tar to stencil the name and address of the client;
(d) httinethe carton;
(e) walkine with the carton; and
(/) placingon the skid.

The elements 'olifting and positioning of carton" and "walking with carton"
may occur in various other jobs in the plant, although not necessarily in the same
manner. Depending on the size and type of fruit, the carton may vary in size and
weight. These are important considerations and will influence the time for these ele-
ments. Furthermore, in other parts of the operation the element "walking with carton"
may recur but the distance covered during the walk may not be the same. These varia-
tions should not deter the work study man from collecting the necessary information
for building up his standard data. This will become clear as we proceed with our step-
by-step approach.
3. Decide on type of reading, i.e. whether you will use readings based on
stop-watch time study (macroscopic systems) or derived from PTS systems such as
MTM (microscopic systems). As explained earlier, the nature of the job and the cost
of applying each system will be the major determining factors. If stop-watch time
study is chosen, suffrcient time must be allowed to collect the readings necessary to
produce statistically reliable data.
4. Determine the factors that are likely to affect the time for each element,
and classify them into major and minor factors. Let us take a simple example: the
case of a worker walking. If the time for this activity is calculated, it will be found that
there is always a variation in the readings. This is due to several factors, some major
and others which may be considered minor. In this particular case the factors may be
indicated as follows:

Activity
Restricted walking starting at dead point and ending at a dead stop.

Factors infiuencing the time

Maior Minor
Distance covered. Physical make-up of worker.
Temperature.
Humidity.
Lighting.
External attraction.
Variation due to time study man.

It is clear here that the time for walking will be affected mainly by the dis-
tance covered; nevertheless, other minor factors will exert a small influence as well,
and these may cause slight variations from reading to reading. 341
 5. When using macroscopic systems, measure the time taken to perform
the activity from actual observations. Here the studyman can choose arbitrary dis-
tances and time the worker for each distance. If it is found that in most cases a worker
walks either L0,20,30 or 40 metres, readings for these distances can be timed and
entered in standard tables. However, this is rarely the case. A worker may walk any
distance between 10 and 40 metres. The studyman will then find it more appropriate
to draw a curve to indicate the relationship between time and distance covered. Let us
proceed with our example of walking and assume that the readings reproduced in
table 23 were recorded.
It is now possible to plot base time against distance. The curve using the line
of best fit will appear as shown in figure 111. For greater accuracy one may also use
the method of least squares to determine the slope and the line of best fit for the curve.
From the curve it will now be possible to derive standard times for values lying
anywhere between l0 and 40 metres. Occasionally the relationship between the two
variables may be curvilinear rather than linear; in such cases logarithmic graph paper
should be used.

Table 23. Restricted walking

Distm€ Actual time Rating Bce time Average

(m) (min) (min) (min)
(a x r:1
J a r t v

0.13 85 0.1 105

0.13 90 0. I 170
0.13 85 0. l 105
0.1 I 95 0.1045
o.t2 90 0.1080
0. l5 80 0.1200 0.ll l8
20 o.2L 105 0.2205
0.21 105 o.2205
0.22 95 0.2090
o.22 r00 0.22W
0.26 80 0.2080
0.22 90 0.1980 0.2127

30 0.29 ll0 0.3 190

0.30 100 0.3000
0.32 90 0.2880
0.30 100 0.3000
0.30 100 0.3000
0.33 95 0.3 135 0.3034

40 0.38 ll0 0.4180

0.37 ll0 0.4070
0.38 110 0.4180
0.43 90 0.3870
0.42 90 0.3780
0.37 110 0.4070 0.4025
342
 STANDARD DATA

Figure lll. Restricted walking

In several cases, however, the work study man may be faced with a problem
where more than one major factor affects the time of operation. Let us therefore
assume that we have a case where a motor-driven circular saw is used for cross-
cutting wood (of the same type). When we analyse the major and minor factors as we
did in the previous example, we may reach the following conclusions:

Activity
Cross-cutting wood of the same type by hand feed.

Factors i4fiuenclng the time

Major Minor
Variation in the Physical make-up of worker.
thickness of the wood. Temperature.
Variation in the width Humidity.
of the wood. Lighting.
Method of holding wood.
Degree of physical force applied.
Machinein good working order.
Experience of worker.

We are assuming here that we are dealing with skilled workers. After a
period of time, it proves possible to calculate the base time for some, but not all,
thicknesses and widths of wood. The results are shown in table 24. 343
 STANDABD DATA

Tabte 24. Base times for cross-cutting wood of varying width and thickness

Thickness (cm)

Width Time Width Time width Time Width Time

(cm) (min) (cm) (min) (m) (min) (cm) (min)

6 0.064 6 0.0'14 6 0.081 6 0.093

t2 0.088 L2 t2 0.t26 t2 0.146
l6 0.104 16 0.130 l6 16 0.181
20 0.120 20 0.160 20 0.180 20

The first step consists in plotting the time against the width of wood for each
thickness (2,4,6,8 cm) (see figure 112). From the resulting curves the missing values
in the table (say, for a thickness of 4 cm and a width of 12 cm) may be derived.
A problem arises, however, if we want to derive standard times for other
thicknesses and widths, say, 3 cm thick and 8 cm wide. Neither of these dimensions is
represented in the table. There are two ways to solve this problem.

l. By calculation. We draw a perpendicular ordinate from the point

representing the required width (in this case, 8 cm) and let it intercept the appropriate
o'appropriate" we
lines of thickness at points a1 arrd a2 respectively (figure 112). By
mean the thickness curves representing the lower and upper values on either side of
the desired thickness. In our example, the required thickness is 2 cm; therefore the
two appropriate curves are those representing a thickness of 2 and 4 cm.

We can then apply the following equation:

T:lar + (az- ar) fl +k

where

7: time we wish to calculate;

4r : time at the thickness of 2 cm (lower limit curve)
(in this case it is 0.072);
dz : time at the thickness of 4 cm (upper limit curve)
(in this case it is 0.086);
f : a decimal fraction representing the required thickness in relation
to a2 and c, (in this case it is halfway between the two, or/: 9.5;'
k : a constant (in this case 0.04, which is the point of origination of the
curve).

By applying the equation we obtain the following result:

344 T : 0.072 + 0.5 (0.08 6 - 0.072) + 0.04 : 0.1 19 min.

 STANDARD DATA

Figure ll2. Base times for cross-cutting wood of varying width and thickness

o
Width (cm)

2. By graphical factor comparison. The first step in this method is to plot

the four curves representing the various thicknesses of wood with width as the in-
dependent variable and time as the dependent variable (the curves shown in figure
112). The point of origination of the four curves is found to be 0.04 minutes (the con-
stant k).

Looking agan at table 24, rffe see that the data for width and time for the
2 cm thickness are complete, and that the points fit well on the curve drawn in
figure I t2 for that thickness. This curve is then reproduced separately and called
a base curve (see figure I 13).

For the second step, we go back to figure lLZ and chose an arbitrary
point representing the width anywhere between the values of 6 and 20 cm on the
horizontal axis. Let us assume that we have selected a point representing l0 cm. From
this point we draw a perpendicular ordinate which will intercept the four curves at
points x, x2, x3 and xa respectively. 345
 STANDARD DATA

Figure ll3. Base curve for cross-cutting wood of 2 cm thickness and of varying width

The third step consists in drawing a factor curve from points that may be
calculated as follows:

Thickness: 2 4

Factor: xr xt'or-:1.2
96 xa ll2
"or-:1.4 x^
-or-:1.6
128
----l
xL x1 80 x1 80 x1 80

From these figures it is now possible to plot the factor curve (flgure 114).
The time can now be readily calculated from both the base curve and the factor curve,
using the following equation:

total time : (base time x factor) + constant

to calculate the time needed for cutting a piece of wood 8 cm wide by 3 cm thick:
T : (0.072 x 1.1) + 0.04 : 0.1 19 min.

In this case, the time needed for a thickness of 8 cm (read from the base
curve) is multiplied by the factor for a width of 3 cm (read from the factor curve). By
346 adding the constant k the total time can be readily calculated.
 STANDARD DATA

Figure ll4. Factor curve for cross-cutting wood of varying width and thickness

12345678
Thicknoss (cml

It can be seen, therefore, that the data required to derive standard times can
be obtained from either tables or graphs. To these data the work study man can then
add any allowances in the usual way. If a firm decides that the same allowance factor
is applitable to every job in a given class of work, it can then express its standard data
in teims of the standard time for each element, instead of using the normal times as we
did.
A word of caution is necessary here. The data collected usually cover a cer-
tain range of readings. It is not advisable to extrapolate these data for values that fall
pieces
outside thi, ,ung". For example, in our previous example the readings covered
of wood ranging from 6 to 20 cm wide and from 2 to 8 cm thick. We know what hap-
pens within thi"rung.; but there is no way of knowing whether the same type of linear
ielationship will continue if we go beyond this range by exceeding the widths and
thicknesses actually studied and by projecting our curves beyond the
points for which
we have time study data.

3. Use of PTS systems to develop standard data

The method used for developing standard data outlined above assumed that
the work study man based his calculations on data derived from stop-watch time
347
study. As was mentioned earlier, standard data may also be developed from PTS
 STANDARD DATA

systems such as MTM or Work Factor. In this case the data derived for eachelement
take into account the normal variations that are likely to arise in the execution of the
job when other products, processes, equipment or materials are used. These variations
result from size, capacity, method of operation, type of tool (which may be simple or
elaborate, few or many) and nature of the work (which can range from jobbing or
small batch work to virtually continuous production).
This is illustrated by table 25, which gives a list of the most common ele-
ments in light engineering and assembly work, with details of their possible variations.
The definition of each element is also given.

Table 25. Standard data elements in light engineering and assembly work

Genqal elements Possible vriations

(cm be used in wveral departments)

Stillage to bench GSB

Bench to tool GBT
Stillage to tool GST
Tangled allowance GTA
Small parts to container GSP

POSITION IN TOOL Easy PE

Medium PM
Dillicult PD
Complex PC

CI.AMP AND UNCLAMP Fingers CF

Toggle CT
Slide cs
Air-operated CA
OPERATE Close and open guard ocG
Foot pedal OP
Lever OL
Safety buttons osB
Flypress OFP
Machine type OMT
REMOVE FROM TOOL Automatic RA
Easy RE
Medium RM
Difiicult RD
Complex RC
Lever out component RLC
TURN (IN) TOOL Turn in tool TIT
Turn tool TT
ASIDE Automatic AA
Tool to bench ATB
Bench to stillage ABS
Tool to stillage ATS
MISCELLANEOUS Count parts MCP
Mark or score parts MSP
Work area to tool WAT
INSPECT OR CHECK Component in fxture or gauge CCF

Element Definitions

GET Covers picking up and moving an object, or handful ofobjects, to a destination.

POSITION IN TOOL Covers positioning an object, or handful of objects, in a tool fixture' etc.; or between
348 electrodes.
 STANOARD DATA

CLAMP AND UNCLAMP Covers all the motions necessary to close arrd later open a clamp of the type that
operates by pressure on the object held; or to hold an object in a tool or fixture, by
a clamping action ofthe fingers.

OPERAT:E Covers all the time and all the manual motions necessary to-
close and later open a guard (OCG);
- grasp or contact an operating control, xtd later return t}le hand to the working
- area, or the foot to the ground;
lperate the controls and initiate the machine cycle (OMT).
-
REMOVE FROM TOOL Covers removing an object from a tool, fxture, etc.; or a part" component or fxture
from under a drill; or from between electrodes.
TURN (IN) T'OOL Occurs when two "Operate" elements follow each other'
and the object must be removed from the tool, turned, and repositioned in the tool;
or the fixture or jig must be turned or moved, in or under the tool.
ASIDE Covers moving and putting down an object or handful of objects' already held'

lVord Definitions
Object Any object handled; such as parts, hand-tools, sub-assemblies or completed articles.
Also, anyjig, fixture or other holding device.
Handful The optimum number of objects which can be conveniently picked up, moved and
placed as required.

Bench The term "bench" includes any table, tote pan or other storage area, convenient to
the tool or workplace.

Stillage A storage box or container on legs, for moving by a hand-lifting or fork-lift truck.
The term "stillage" includes a palle! the floor or any other storage device at floor
level.

Tool A general term to cover any fixture, jig, electrode, press or other tool used to hold
or operate on an object or objects.
One tool can be positioned in another-for example, a parts-holding fxture under
a drill or a welding electrode.

Figure 115 illustrates a typical operation in a light engineering plant. Many

operations, including the one shown here, contain one or other of the following se-
quences of elements (note that other sequences are also possible):

(a) eetmaterial; position in tool; operate machine; remove part; aside; or

(b) get material; position in tool; position fxture in machine; operate machine;
remove fxture; remove Part; aside.

In figure 116, sequence (a) is shown as applied in power press work, and in figure 117
the element TRANSPORIhas been further analysed and the distances indicated.
To develop standard data from a PTS system, each sequence of elements is
now analysed, using MTM-2, for example. It is also possible to build up from MTM-2
and other PTS systems a data bank for certain standard operations, with their poss-
ible variations. Standard data developed in this way may be presented either as a table
(as in figure 118) or algorithmically (as in figure 119). Figure 120 reproduces a form
which can then be used to record the time for a particular activity using data derived
from either figure 118 or figure 119. 349
 STANDARD DATA

(a)

(b)

I Position 'l Position

Plin fixture
machine
ln in tool
I I

Work-holding device

350
 STANDARD DATA

Figure 116. Basic elements of power press work

POStflON
II'.,"'"^r'
OPEN GUARD

Figure 117. Power press work: example of TRANSPORT elements and distances

TBG (10 cm)

TPB TPG
(61 cm) (61 cm)

351
 STANDARD DATA

Figure 118. Power press work: example of standard data determined by MTM-2
( presentatio n)
ta bu I ar

Element Code tmu Elemont Code tmu Element Code tmu

GET part POSITION in tool REMOVE from tool

Flat part
Flat GF1 21 eject
Auto RA- O
GFz 31 Stops PFS1 27 Easy RE1 17
Use tool GTS 15 PFS2 30 RE2 17
Shaped GS1 19 Pins PFP1 31 Medium RM1 36
GS2 28 PFP2 33 RM2 52
Tangle, add GTA 20 Difficutt RDl 50
Weight GW Shaped part RD2 50
Moulded PSM1 31
Weight GW
TRANSPORT PSM2 39
from guard, and TRANSPORT (as above)
To or Stops PSS1 38
Bench TBG1 4 PSS2 41
ASIDE part
TBG2 4 Pins PSP1 31
Pallet, TPG1 18 PSP2 35 Auto aside AA. O
etc. TPG2 18 Weight PW Throw AT1 7
Tool TGT1 18 AT2 7
TGT2 18 OPERATE PBESS Lay aside ALl 10
Bend, add TB- 61 Close guard AL2 lO
Step, add TS- 18 Auto OCGA 0
Stack aside AS1 11
One hand OCG1 21
AS2 19
Weight
To or from tool and Two hands OCG2 30
Guard TGT'I 18
TGT2 18 Operate press
Store TSTI 11 Auto OPA *
TST2 1 1
Foot OPF *
Hand o THT1 4 Buttons OPB i
2ndtool TTT1 14 Machine cycle OMC *
Tff2 14
* For each press use machine
To or from pallet and data or time study
'Bench TPBI 32 Open guard
TPB2 32
Store TPS1 42 Auto OOGA O
TPS2 42 One hand OOGI 22
Guard TPG1 18 Two hands OOG2 31
TPG2 18
Weight PW

irrole.' Last character in codo indicatss: 1 One-handed

2 -
-Two-handed

352
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OF
 STANDARD DATA

Figure l20. Power press work: standard data application form

Press type: Prepared by:

Part: Date:

Operation: Standard minutee:

seq. Motlon doscdptlon Machlne tsft hand Rlght hand Charge

no.
Code tlhu Code tmu Code tmu tmu

I
tout,r, I ruactrlne
I
R.H.

Basic minutes (+2,(ml

Total basic mlnuteg
Rel8xatlon and con-
tlnsency allowance (%l
Standard mlnutes
354
 STANDARD DATA

4. Use of computing equipment to calculate time standards

It is evident that the design and the development of standard data and time
study in general involve a Eteat deal of calculation. Computing equipment is now
being used more and more to make the task easier. In particular, mini-computers
and small programmable calculators (see figures l2I, 122 aad 123) have proved
invaluable and have brought about considerable savings. Several programmes have
been developed for use with these calculators, for instance for time study analysis, for
system error and control and for the control ofdrift.
In a typical case using a'oTime Study Analysis Programme", the first and
most time-consuming step consists, as usual, in multiplying each observed time by the
relevant rating (see figure L24). The programme now produces a histogram of obser-
vations for each of the three elements in figure 124. This is probably the most impor-
tant feature of the programme, as it enables the work study man to see whether the
element he has selected is, for example, normally distributed (as is the case for element
l-see figure 125); or skewed (as for element 2-see figure 126),inwhich case more
readings may be needed; or bimodal (as for element 3-see figure 127), which shows
that the element has been incorrectly selected and that new break points must be
selected as two activities appear to overlap). The calculator automatically produces
the highest value of the histogram, its lowest value, and the intervals and the fre-
quency of each column.
When the basic and standard times have been calculated for each element,
the calculator produces various items of information to help to determine whether the
study is reliable. First" the total standard time for all the elements is calculated as well
as the total effective time. Second, after the total ineffective time and check times are
entered, the programmed calculator produces the total recorded time. Third, it com-
pares this with the total elapsed time to give the percentage enor, and calculates the
number per standard hour. The definition of all these terms is given in table 26. Figure
128 shows this sequence of calculation as computed by the calculator. By reading the
percentage erroro the work study man can then decide whether to accept or reject
the study.
lt can be seen that programmes such as the one described above permit the
calculation of a wide range of values in a very short time. The programmes are sup-
plied on magnetic cards or magnetic cassettes with a complete listing and with
operating instructions. Consequently, they can be used with a minimum of instruc-
tion.

355
 STANDARD DATA

Figure l2l. A small hand-hetd progiammable calculator, the Hewlett-Packard 67, showing
"the programme cards. Similar machines are available from several other manufacturers

356
 STANDARO DATA

Figure 122. A small programmable calculator, the Hewlett-Packard 97,

providing a printed output. Similar machines are available from several other manufacturers

357
 STANDARD DATA

Figure 123. A small computing system, the IBM 5llo, which can be used for standard data
- calculations. Similar machines are available from several other manufacturers

358
 STANOARD DATA

Figure 124. Time study analysis programme

OBSERVED DATA - ELEMENT 1

Watch reading
(centiminutesr) 20.50 1.00 8.50 12.40 12.50 2.50 4.O0 6.00 8.80

Rating
o-100 75 100 95 85 100 120 110 115 85

Watch reading
(centiminutes) 10.40 1 5.70 7.60 7.20 6.40 15.30 8.80 5.20 8.40

Rating
o-100 95 75 65 100 75 75 95 105 1 10

Watch reading
(centiminutes) 9.OO 10.50 9.90 9.40 10.80 14.90 6.60

Rating
0-100 65 85 110 75 85 65 110

OBSERVED DATA - ELEMENT 2

Watch reading
(centiminutes) 20.80 1.00 14.60 2.91 4.30 7 .10 1 3.00 1 3.1 0 6.92

Rating
o-1 00 75 100 95 1 10 120 100 75 95 65

Watch reading
(centiminutes) 13.60 9.52 7.70 8.42 8.46 7.56 3.78 10.20 10.94

Rating
0-1 00 85 105 100 95 65 75 95 loo 95

Watch reading
(centiminutes) 4.52 8.47 6.50 5.16 5.18

Rating
o-1 00 95 105 100 120 1 10

OBSERVED DATA . ELEMENT 3

Watch reading
(centiminutes) 26.10 1.00 3.36 16.30 3.42 9.50 6.00 5.42 14.80

Rating
o-1 00 65 100 95 80 105 100 120 70 75

Watch reading
(centiminutes) 14.60 17.20 21.60 5.10 14.20 17.00 13,30 5.57 8.90

Rating
0-1 00 95 65 100 100 90 60 95 100

Watch reading
(centiminutes) 6.00 6.10 5.90

Rating
0-100 90 100 110

| 1 centlminute: r/r@th minute.

359
 STANDARD DATA

Figure 125. Time study analysis programme for element 7

fiUTu ii iiilT
itlTEF; riLE i.trJ.
T I i,iE 5I UIIT
P Fj l,l l: Fl Fl t'1
l,: l: :,: l': l,: :": !: ,,; l, t: l'l i,i li l.i i; lt
Ir0 TrlLl t!F,t{T TiJ i . i!:1!-i
El.l'l EF;- 1t:18
I: T I llE r. r:nE:1 Fr..'E [J. EIFT
FttlT: t,iE 5:.rt Histogram shows
1 rEFr:ll tl r r:f,lt l, F:., 5 ii. 4rlEt normal distribution
i-ifi i1 rr fl,iri il il,t ii Ji J. i' ri r:
for this element
EI-EI.IEHT 1 rl . l{48

lE.
E. 154
5Bt:l
t.J
15.'JEil:1

ff.115
?5 t
1. El-lt:i E. EB'3
1BE !5
E. r:1 1 El I:1 . E1E4

E. 5r:li-l 5. IEE
t5 T E1E
l:1- 8E I t:l . E155
+ :":
U;, .-'i
,. t. 4EB E. .lBr:,1
ET= t:i. r-iEE
r-. sl tlE
E. 185 r:1 , Egt
FEi.lT
I e. 5L]B g. EtrlE I
IEE Fr5 I
. 11.5 l:,r.115,.? FiES i rlLLr:r1,1
u1
lt
t. SErEl 1 ,:1 . SrlEt
r:r lHF-E: fiLLr_'lll
:-1
1eLl r:..-r
EI . E:]E E. r-rgg iTIt T Il{F.= B. E:ri

9. TFB I.1I:IEE ELET,.lEI.{TE

4. Lll:1F
I
I lEl 'lE5
i.
I lEt
El44 l:1. L Et:J
: Hrr

.A
h. E!ErEl t. 4El0 I
r aE
I:J t5 I

E1. E6t i:l . Ei 1

The standard time for

E. El:tLl 1 t_1. EEtt:t the element is automaticallY
determined from basic time,
,l . riti i E1 . tlt i1.'{ relaxation and other allowances.
.{. ,.1
1li1. +Ef-'l 1
"
r:r Et

f ._r E, ,-r
t:"1 . E}'-t l:1 . E1!,-J

1 -a, i Lll:i r:, , F-, [:l i:1

i 1E1
rt"lli [_r.r-ii..-.t

I ll rIFt
I t- f r,.:
360 rl .t.':'
 STANDARD DATA

Figure 126. Time study analysis programme for element 2

':1,'i.i,

i:l [,f;F-:ir
:..i. i|:r!
i:,
rl ,1i1
i " [L-1':i
l FIJ
fi. 811i
{,a! r Lr_,r-,
1rir-{
I .+. E.l:ttj -
': .:i i t]8
11 , 1 l'"1 rJ, l iji
.,: .'.i18
1 ltil l-l
ti I
r_r r rjt.j.i ' t:14

;. :jl:1lj i ! ...rir_r
f ._r
i n,:, I
tJ. r:15I

,r. 1 BF-t
1 i:l El 185
Li " r:17 I Li . it 8,"1

1::!. t:lE(t i,5t:lEl

fJ 185
il. t:l5il l:. ElbE

1:. 1 Brir 5. 1EE

I IL1
rr. 1i; r-l ! tl r-' I

r:,. trEt I. 1Er3

1 1t:1
ri
r_. ,-{E:
r_r.fl
E. Lt4!:
1.J. L;FIJ Et{TEl.'
'n5 1EF:Fr-lRt
{"1. 1 1 r: E i.{nt,lE

'.1 , g!r:l + i,'l

The histogram
1,:'15 shows the data
t:1. 1 116
<- to be slightly
skewed.
I. ;EE More observations
I El:l +Hli
+]t may be needed.
[1 , E,7I
+l{
E. {EE
,1C ET= i:r. E?'-r
B. EtEg
FFi tt 3
t
E. 4Er:1
F-, J I
rjl . l:t55 RE51 ttLLt:tu
1t
i . (16 t:l rlTHEEt qLLrll.l
,
i:r. r:rJi ETII T I IrE= E. BT I

:r. lEEt NI]FJE ELEI'1EI,{T5

I lEl
r::. fi:}l; f llr:i 361
 STANDARD DATA

Figure 127. Time study analysis programme for element 3

E LEi,IEI.II

ib.1Ln
r:. -r
r " I IC
1.:lE,E
lEE
u'13tl:1
1i. tEEr
:l . JiX 6E
:r ._r !:1 . E'r] E
l:i . l:1'j'l
._tiJll:l

1E. ;EIE !5
HE El , EI;]
Ei. 1:lrl
r-r . 'l El tj
:;. 4iEt 1 ElE
I Er3 fi " rtEt
tl . B:lE
E. ritEEr
,-r
:r. 5Et-1 E
IEE E. t:154
E. 895
F_. I EilJ
t:. l:tEB I ErEl

ltB E. Br: t
i:l . t:t?!
:;. 5EB
5. 438 1 1[t
Frlr B. EEE
t:l. 1:1::l'rl
EI.ITEFj This element has
i 4. EEE 1 E F.F] IJ R::1 been incorrectly
75 l:' l.lUtlE selectod resulting
in a bimodal dis-
El.111
+ i*l tribution.
I +. r:EE New break points
?5 for the element
tJ. I -?'"1 need to be selected.'
+ ],i This could not have
1 ?. EEE been detected if
FEI the normal practice
l:r, l lEl +!{ of finding the
IrURL f'lrlli arithmetical average
t1.6EE n:;5:.: of observed data
ET ET.= tt. EEE had been carried out.
8.148
FEr,:ll
5, I Er:r 1

]EE .:
l:l
' t:15 1 F:E5T HLt.II,I
1t
J 1. r'lj1t:t r:iTHEB Ftt-L rlt,l
1 Er:i J
[:i. 1 +! lTIt T 1 tlE= f. Er::rI
l l. r:t{E Hr_rE:E ELEliENfS
i r:r T TE5
362 E, I 1'.i : Hrl
 STANDARD DATA

Figure 128. Time study analysis programme calculating various

time factors and percentage errors

r{ ;i }i ir: il .ii }i: :t{ ::{: :.i }i l{ ;i }q ii }.i

Tri 1' !i-1"ii t'1 I tl

tr.llf
EI-F -rIftF.. 6.5:il
1r.lIFF 11tlE!
!_r r I gJ
;:1. 1 4L:

i:i" I i E
8. 198
Ttj r" E, tl:11
f Lit T I ITE!
I r LJ'-r

I. t:5r:.1
Tr.lT :l, :i4E1
r'uT F:Er_ TIl,lE=
I 1 .'.111
STHt:T rIl.l t
1.-J t!
l.-r .i
lLI Ii

t r 1a-l

1I. Errjr

Fl-nFlEI! T I llE=
1I. EirJ
I h'E:r] F: = J .,r

Il !.1 . ..'t T .r-l Hi.tUFl=

iih. tE

Table 26. Definition of terms, time study analysis programme

(from 8.5.3138/1959)

Defmition

CHECK TIME The time intervals between the start of a time study of the first element (TEBS:
"time elapsed before starting') and the finish of the last element and the finish
of the study (TEAF: "time elapsed after frnishing").
SELECTED BASIC TIME The basic time chosen as being representative of a group of times for an ele-
ment or combination of elements.

EFFECTIVE TIME That portion of the elapsed time, excluding the check time, during which the
worker is engaged in the proper performance of a prescribedjob.
TNEFFECTIVE TIME That portion of the elapsed time, excluding the check time, spent on any activity
which is not a specified part ofthejob.
ELAPSED TIME The total time from start to furish of a time study.

UNACCOUNTED TIME The dilference between the elapsed time and the sum of the separate times,
including check times, recorded during a time study.
PERCENTAGE ERROR The difference between the elapsed time and the recorded time, expressed as a
percentage of the elapsed time.

363
 The use
of time standards

1. Define the work covered by the time standards

When the studywork has been completed, it is important that a detailed
record be made of the methods, tools and equipment used and of every feature of the
operations which could possibly have a bearing on the time. This is necessary because
changes in the work content of an operation affecting the time will also aflect planning
and costing; it is doubly important where the time standard is to be used in setting
rates of pay under an incentive scheme. It is a cardinal principle of all sound incentive
schemes based on time study that the time standards set should not be changed except
when the work content of the job is changed, when there is a change in the organisa-
tion of the work, or to correct a clerical error.r
When time standards are to be used as the basis for an incentive scheme, it
is usual to prepare two documents to describe and define completely the way in which
time standards are compiled and the working conditions to which the standards refer.
These two documents are known respectively as the technisal set-up and the work
specification.
The technical set-up is essentially a work study document, having no
reference to rates of pay, control of workers or other matters of contract between
employers and employees. It shows in summary form, in suitably presented tables and
graphs, the main results of the studywork undertaken in the section and how all the
iimi standards which have been set have been derived. It contains all the information
necessary to calculate fresh time standards, should the jobs or the working conditions
change, in so far as these fresh standards can be compiled from the studywork already
undertaken. It is thus in effect a manual from which time standards can be built up.
It will be necessary to compile a separate set-up for each technically
different section of an enterprise, since the methods by which time standards are
compiled will differ from section to section. Thus in a vitreous enamelling shop
theri would probably be one set-up for the sprayers, another for the operators ofthe
shot-blast machines, a third for the furnacemen, and so on.
Summaries of all the data on which the technical set-up is based should be
attached to it including-

I ILO: Payment by results, op. cit., p. 183. 365

 flow process charts showing the improved methods developed;
analysis of studies sheets;
relaxation allowance calculation sheets;
data from predetermined time standards (pTS);
curves and graphs relating to standard data.

The greatest care should be taken of the technical set-up and of all the
original documents attached to it, since they are essential evidence in any disputes
which may arise. They are also of great value in compiling time standards for similar
work in the future. Technical set-ups are normally frled in the work study department,
where they are available to the management or to the workers' representatives
whenever they may be needed.

2. The work specification

The work specification thus represents the basic data on which the con-
tract between employer and employee for the operation of an incentive scheme rests.
The amount of detail necessary in a work specification varies greatly
according to the nature of the operation concerned. In machine shop work in the
engineering industry, where a large number of different jobs are done on machines
whose methods of operation are broadly similar, general conditions governing all jobs
can be established for the whole shop and only variations in detail need be specifically
recorded.
On the other hand, where an operation involves a whole shop or department
and will run for an indefinite period substantially unchanged, as is the case in parts of
the textile industry, the work specification may be lengthy and detailed. For instance,
the work specification for draw-frame tenting in one spinning mill is 18 pages long and
includes specifications for the alternatives of cotton or artificial fibre.
Generally speaking, the following points should be covered by a work
specification, which should, of course, embrace the standard method laid down as a
result of the method study:

A. Details of the workpieces or products, including-

drawing, specification or product number and title;
material specification ;
366 sketch, where necessary, ofparts or surfaces to be treated.
 THE USE OF TIME STANDARDS

B. Details of the machine or plant on which the operation is performed, in-

cluding-
make, size or type, plant register number;
speeds and feeds, pulley sizes or other equivalent data;
jigs, tools and fxtures;
other equipment;
sketch of workplace layout (where not available on the method study).

C. Operation number and general description of the work covered.

D. Quality standards, including-

quality grade;
flrnish and/or tolerances, where applicable;
checking and gauging requirements, gauges and other inspection apparatus;
frequency of inspection.

E. Grade and sex of labour, including-

direct and indirect labour;
part-time assistance by inspectors or supervisors.

F. Detailed description of all work involved, including-

repetitive elements, constant and variable;
occasional elements;
indirect work: setting up and breaking down;
cleaning, greasing, etc., and frequency with which such operations are
carried out.

G. Details of time standards, including-

standard time for each element, job or operation, as appropriate;
allowed time for all indirect work, with a note on how it has been assessed;
percentage relaxation allowance included in each element time;
other allowances.
H. Clerical procedure to be carried out by operatives in recording output and
booking waiting time.
I. Conditions under which the time standard is issued, and any special
provisos.

It may be necessary to supply copies of the work specification to the

management and to the departmental and shop supervisors and, in the case of
specifications affecting a large number of workers, to the workers' representatives.
The manner in which the time standards are made known to the operatives
depends largely on the nature of the work. If the job is one that is done only by a
single worker (the one who was timed), it is usually enough for the work study man to
tell him personally, in the first instance. When work study has been accepted, workers
do not usually want lengthy explanations: what they are interested in are the targets at
which they must aim in order to earn a reasonable bonus. Time standards are likely to
be better understood if they are put in the form: 'oYou will need to do 12 pieces an 367
 THE USE OF TIME STANDARDS

hour for time-and-a-third", or 'o l7 hanks a shift for time-and-a-third" than in the
form: " 13 standard minutes per piece". If anything appears to be wrong with the time
standard, further details will very soon be sought. If a whole shop is on the same type
of work, as is often the case in certain process industries, including textile spinning,
summaries of time standards should be posted on the notice boards in the department.
It may also be desirable to read relevant parts of the work specification at a
departmental meeting. This will have to be done where most of the people affected by
the time standards are illiterate. In batch production the standard time is generally
written or printed on the work ticket, job card or process layout.

3. The standard unit of work

Standard times are generally set down in the following forms:

x minutes per piece;

y minutes per 100 (or per 1,000) pieces; or
z minutes per ton, metre, square metre, etc.

They are sometimes calculated or translated into hours. These time values represent
the output at standard performance, that is, at 100 rating.
The minutes or hours allowed for any given job are not minutes or hours of
continuous work. Each unit of time contains within it an element of relaxation.
The proportions of relaxation and work will vary according to the heaviness
of the work. In extremely heavy, hot work such as furnace tending, the proportion of
relaxation may be 50 per cent or more.
Since the standard minute is a measure of output it can be used in measur-
ing and comparing productivity, which may be represented by the ratio-

output of work in standard minutes

Performance x 100
input of labour time or mashine time in clock minutes

minute is that it can be used to

A particular advantage of the standard
measure and compare outputs in dissimilar types of work, the accuracy of the com-
parison being limited by the consistency of the time standards.

4. Production planning and the utilisation

of plant and Iabour
One of the causes of ineffective time due to management shortcomings men-
tioned in Chapter 3 is failing to plan the flow of work and of orders, with the result
that one order does not immediately follow on another and plant and labour are not
continuously employed.
In order to plan a programrne of work effectively, it is necessary to know
368 precisely-
 rHE USE OF TIME STANDARDS

1. What is to be made or done.

2. The quantity involved.
3. What operations are necessary to carry out the work.
4. What plan! equipment and tools are needed.
5. What types of labour are needed.
6. How long each operation may be expected to take.
7. How much plant and equipment of the types necessary are available.
8. How much labour of the types necessary is available.

The information on items 1 and 2 is generally supplied by the sales office or

commercial department.
The information for determining items 3, 4 and 5 is supplied by process
planning and method study.
The information on item 6 is supplied by work measurement.
The information on item ? is supplied from plant department records or
those of the department concerned.
The information on item 8 is supplied from personnel oflice records or those
of the department concerned.
Once this information is available, it is a matter of simple arithmetic to
match the requirements with the available capacity. Both the requirements and the
capacity available to fulfil them must be stated in terms of time.
Requirements will be stated as-
number of operations of each type to be performed x expected time for each
operation.

This must be matched against the total time available on each type of plant
and with each type of labour necessary to perform the operations.
When a programme is being planned, only the actual times which the opera-
tions may be expected to take are of interest. These will depend, among other things,
on whether the general conditions in the plant-including the state of labour-manage-
ment relations and the system of remuneration in use-are such that the workers are
working at their best rate. Where this is the case and the work study application has
had time to setfle down, these times should be those of the average performance of the
shop or department as given by the production records over a period. This may even
apply to an individual machine or process. It is the only realistic basis for such
calculations. The times are arrived at by multiplying the standard times by

100
Average performance

The plant and labour capacity available is expressed in'oman-minutes" or

o'machine-minutes", due regard being paid to any time it is necessary to allot for
cleaning, setting up, dismantling, change-overs, repairs, etc. 369
 IHE USE OF TIME STANDARDS

The matching of production or operational requirements to capacity in this

way makes it possible to-
(a) show whether there is an insuffrciency of any type of plant or labour likely to hold
up the programme or cause bottlenecks in the course of production and, if so, its
extent;
(D) show whether there is an excess of capacity in any type of plant or labour and its
extent;
(c) give accurate estimates of delivery dates.

If the management can have such information, compiled from realistic stan-
dards of performance, available well before production is due to start, it can take steps
to prevent hold-ups from occurring. Alternatively, it can start looking for work to fill
up spare capacity. Without such standards it has no sure basis for doing either of
those things.

5. Estimating production costs

The success or failure of a firm in a competitive market may depend on the
accuracy with which it is able to price its products. Unless the manufacturing time of
the product is accurately known, the labour cost cannot be estimated, and many in-
direct costs dependent on time-such as plant depreciation, fuel and power consump-
tion, rent, and the salaries of staff and supervision-eannot be accurately determined.
If the management can rely on the accuracy of the costing, economic prices
can be fixed. If these are below those of the firm's competitors, the management can
be happy in the knowledge that it is underselling them in safety; if they are above, the
cutting of costs can be undertaken with more assurance than would otherwise be the
case and with a knowledge of the margins available to be cut.
Standard and actual labour costs per 100 or per 1,000 standard minutes of
production are frequently calculated each week from the weekly control statements.
Since the actual labour cost per 100 standard minutes takes into account both direct
and indirect labour costs, it is the more useful figure to use for estimating production
costs.

6. Standard costing and budgetary control

Work measurement provides the basic information for setting standards of
labour costs and the means of controlling them. These standards can also be used as
the basis of the labour budgets for budgetary control; they provide certain elements of
the information necessary for the production and indirect expense budgets and,
related to the sales budget, indicate the plant and labour capacity likely to be available
over the period ofthe budget.
Besides providing the standards, work measurement also provides, accu-
rately, the actual performance figures. The need for such accurate standards cannot
be overstressed. The absence of complete cost information is at the root of much bad
management and of many failures of industrial enterprises. Labour costs will, as
usual, be based on standard times, with appropriate provision being made for devia-
370 tions from standard performance.
 THE USE OF TIME STANDARDS

7. lncentive schemes
Direct incentive schemes based on output do not necessarily follow on an
application of work measurement. There are many enterprises where time studies are
made but direct incentives are not employed. One of the reasons why a good deal of
attention has been paid in previous chapters to features of time study particularly
related to its use in connection with incentives is that no discussion of time study
would be complete without them; moreover, in practice the installation of an incentive
scheme is generally one of the principal objects of a time study application.

The merits of work measurement as a basis for incentive schemes lie in

several features inherent in the techniques, namely-
(1) The times are based on direct observation and on recording by the most accurate
practicable means.
(2) Enough observations are taken of all elements of work, both repetitive and occa-
sional, to ensure that the times finally selected to make up the standard time are
truly representative and that random occurrences are taken into account.
(3) Full records are made
and retained so as to be available for examination by either
management or workers, should the occasion arise.
(4) The recorded times and associated data give a factual basis to any management-
labour negotiations on performance standards, as opposed to the bargaining
based on opinion which must take place when times are estimated.
(5) Properly applied method study followed by work measurement enables the
management to guarantee the time standards with reasonable assurance that it is
not exposing itself to risks of perpetuating uneconomic rates.

It is important for the success for any incentive scheme that the workers
should know as quickly as possible the bonus they have earned. Wherever possible,
this information should be made available the day after the one to which it refers. It
may be shown in money units, as a percentage of the standard performance, or as the
aYerage number of standard minutes produced per hour. In these latter ways the
figures can be posted on the notice board without workers actually seeing each other's
earnings. In many firms it is the practice for the shop clerk or foreman to tell each
operative his performance, which enables him to raise any queries on the spot. When
workers get used to thinking in standard minutes, they generally know at the end of
each day what they have earned and tend to regard the daily figures as confnmation.

The value of this practice to an incentive scheme is as follows:

(1) The effect of the operative's own actions on his earnings is brought home to him
while the events concerned are still fresh in his mind.
(2) Any queries on the amount of bonus due can be taken up and corrections made, if
necessary, before the wages are made up.
(3) The posting of the figures daily on the notice board, where this has been agreed to
by the workers and their representatives, adds interest and may stimulate a com-
petitive spirit. 371
 THE USE OF TIME STANDARDS

(4) Repeated confnmation of their own calculations by the management's figures, or

clear explanations where they differ, tend to increase the confidence of the
workers in the fairness of the system. Conversely, repeated mistakes by the wages
staff can rapidly undermine their confidence.

8. Organisation of the recording system associated

with work measurement and labour contro!
A full application of work measurement, when associated with an incentive
scheme, has to be backed by a system of recording operatives' times and output of
work. These times and output figures must then be assembled at a central
point-usually the accounts department once the work study application is running
properly-where they can be worked out and put into forms suitable for use in com-
piling the bonus earned by each worker and providing the management with compact
and easily understandable statistics for the control of factory performance and costs.
Devising a system suitable for use in the organisation in which he is
employed is generally one of the jobs of the work study man. Any such system must
have certain characteristics. It should-

(a) provide accurate and full information;

(D) ensure that all the necessary information is recorded as a matter of routine and
transmitted with the minimum delay to the central office;
(c) be simple to understand and to operate and as nearly as possible foolproof, so
that all the routine work can be carried on by comparatively unskilled clerical
staff;
(d) be economical of staff;
(e) be economical of paper.

Working out a system to fulfil all these requirements for any but the small-
est works engaged on the simplest type of manufacturing is not easy, and a chapter
could well be devoted to the subject. Space does not, permit this, however, and the
variety of systems for different applications is such that any set of examples given here
would run the risk of being too complicated for some enterprises and insuffrcient for
others. Comment will therefore be confined to some general notes and to the basic
data required together with its probable source.
The sheets on which output and performance information is summarised
and reported to the management are known as control statements. In a fully
developed labour control system there will probably be three different labour control
statements, prepared at different intervals and for different purposes. A daily state-
ment may be prepared each morning, separately for each section of the organisation,
to indicate to the foreman or supervisor in charge of the section the results of the
previous day's working. Once a week the weekly control statement will be compiled,
usually on a departmental rather than a section-by-section basis. The weekly state-
ment will go to both foremen and departmental heads. A single sheet frequenfly has
372 space for the record of 13 weeks of work, a fresh line being used each week, so that
 THE USE OF TIME STANDARDS

Table 27. Minimum data required for work measurement and labour control records

Information

( l) Hours of attendance of each operative Clock card or time sheet

(2) Standard time for each operation Job card or work study oflice

(3) Times of starting and finishing each opera- Job card or work sheet (via shop clerk)
tion

(4) Quantities produced Job card or work sheet (via work checker)

(5) Scrap or rectification: quantities and times Scrap note or rectification slip (via inspector and
shop clerk)

(6) Waiting time and non-productive time Waiting time slips or daily work sheet (via shop
clerk)

the current week's results can be compared with those of earlier weeks during the
same quarter. The control statement which goes to the top management is usually
made up monthly, on either a departmental or a whole-works basis.
In any system of recording associated with work measurement and an in-
centive system, the minimum data given in table 27 must be recorded and eventually
transmitted to the wages and cost offices.
It
should be noted that the application of work measurement will almost
certainly entail an increase in clerical staff. The idea of this frightens many managers,
who fear increases in their overhead expenses, forgetting that the increased cost is
likely to be very small compared with the savings which the techniques of work study
can make in their total costs of production or operation.
The design of labour control statements varies according to the needs of the
organisation, but the usual form is divided into two palts. In the first part, the labour
utilisation and effectiveness are expressed in terms of time; in the second part, the
figures are translated into costs. In addition to the output (in standard minutes) and
the clock minutes worked, from which the productivity of the department may be
calculated, waiting time and additional allowances are analysed by causes, so that the
manager can at once question and take action on any cause of excessively high
waiting time, and can see the cost of it.
This concludes the section of the book devoted to work measurement.

373
 Part four
From analysis
to synthesis:Newforms
of work organisation
 Ghapter
Combined methods
and tasks: New forms
of work organisation
1. Method study and work measurement:
basic tools for job design

In the preceding chapters we have thoroughly discussed modern work study

techniques. Since the introduction of these techniques at the beginning of this century,
work study has become an effective tool in improving the performance of enterprises.
Few developments have contributed so much towards attaining that goal. Moreover,
the underlying principles of these methods will, for the foreseeable future, continue to
be of immense importance in the great majority of enterprises, regardless of their size
or area of economic activity.
Let us briefly summarise the basic significance of systematic work study for
the development of better methods of work.

METHODS: SYSTEMATIC v. HAPHAZARD

The first rule of work study is that each task must be systematically
analysed in advance and the ways of carrying it out must be thought through. If the
task in question is to be carried out only once, perhaps this preliminary analysis is of
no great importance-indeed, there might be no point in paying too much attention to
it. But if the task is to be carried out repeatedly, we can easily see that much is to be
gained by carefully scrutinising the manner in which the task is executed. Every move-
ment that can be eliminated or improved, every time span that can be shortened will
produce economies-and if each task is repeated many times, as happens with mass
production or long runs, the saving of even tiny movements or of a few seconds here
and there can be of crucial economic importance.
It can thus readily be seen that if systematic analyses of this kind are not
carried out, preferably before production is begun, inefliciency will in effect be built
into the job.

WORK ANALYSIS: STEP-BY-STEP EXAMINATION

An important feature of work study is therefore the systematic analysis of
the job, that is the division of a task into its various component parts followed by a
careful examination and discussion of each part. By thus breaking down a complex
problem into its underlying elements, a clearer and more readily understandable pic-
ture of the task can be obtained, and a good method of carrying it out can be deduced. 377
 In Chapter 8 we examined various methods of breaking down work procisses into
small parts. In the same chapter we went over the questioning technique-a method of
questioning everything that is done and taking nothing for granted, with the aim of
finding new alternatives, new combinations and new ideas.

PRE-SET TIMES FOR VARIOUS MOVEMENTS

One of the most important features of modern work study is that it is poss-
ible to fx
in advance, with moderate margins of error, the times necessary to carry out
different movements. There are many different methods of doing this, ranging from
summary estimates to highly refined PTS systems. One point that these methods have
in common, however, is that they all contain a more or less established method of
determining, on the basis of the characteristics of the work in question, the 'onormal"
time that a task should require.
This process of pre-setting times for various tasks is of overwhelming im-
portance in production management. Most important, it makes it possible to test alter-
native methods and combinations of methods of performing a certain job and to deter-
mine which alternative is the most time-saving. Furthermore, with the help of these
systematic time guidelines, it becomes feasible to distribute work assignments among
different individuals and groups in order to plan production more efftciently and to
construct a foundation for discussing production-linked wages and similar incentives.
Again, this is an element of modern work study that is virtually indis-
pensable in normal industrial activities. Without the help of work study methods and
systematic time formulae, the determination of guidelines would be pure guesswork.

THE LATEST ROLE OF WORK STUDY: FROM ANALYSIS TO SYNTHESIS

So far we have discussed the basic role of work study in the design of in-
dividual jobs and of work organisation. Before we go into more detail, it should be
emphasised that the development of method study and work measurement has been
continuous, so that it is now possible to apply work study to any kind of activity.
Furthermore, the workers' understanding of and active involvement in work study has
increased rapidly.
With this point clear in our minds, let us now turn to the question of how
the basic "building blocks" of method study and work measurement can be put
together in designing jobs, and how work organisation can best be shaped in other
respects. We shall divide this discussion into three parts, corresponding to three
organisational levels-

l. Design of individual work roles.

2. Design of group work in production.
3. Design of product-oriented organisations.
A
detailed examination of these topics falls outside the scope of this in-
troductory book, and we shall limit ourselves here to a discussion of some of their
378 basic features.
 NEW FORMS OF WORK ORGANISATION

2. Design of individualwork roles

cUIDELINES lN THE DESIGN OF JOBS: SOME EXAMPLES
In putting together an individual work role with the help of the fundamental
building blocks we have been discussing (that is, the component parts of each task and
the description of methods), we may adopt a number of criteria as guidelines for
satisfactory job design.
Most important are the economic aspects. With the help of systematic work
study the component parts of a task are put together in such a way that as little time
as possible is required to carry it out. In this book we have so far confined our discus-
sion to this point.
However, the design of individual work roles is too complex to be effected
with the aid of a single criterion-that is, what appears on paper to be the shortest
time needed to carry out a task. In practice, numerous different factors must be con-
sidered.
Some of these are purely practical considerations, such as the need for dif-
ferent types of machinery, the nature of the different components of each job, and so
on. For example, if it takes ten minutes to carry out a particular component part of
the task and if this component part is repeated lO00 times within a 50-man work
group, it is easy to see that the results of this study must be combined with other infor-
mation about the work situation in order to arrive at a reasonable division of the task
among the various members of the group. This example is given merely to indicate the
problem, which we shall not examine here. There is, however, one special group of
factors that we must look at more closely: namely, the worker's needs and
preferences, his experience of the work and his reaction to different kinds of work
organisation. This is a new and important dimension, since it implies the need to adapt
work design to the individual's wishes and capacities, to create jobs in industry that
offer a reasonable challenge, and to provide the worker with the chance of a working
climate that offers some degree of satisfaction. The reader will no doubt recall that this
point was made earlier, in Chapter 5. Here we can identify three important factors
that can lead to increasedjob satisfaction-

(1) A moderate amount of variety in the work done.

(2) Decoupling of man/machine processes, that is, freedom from being tied to a
machine during the entire working day.
(3) The opportunity to integrate various service and auxiliary tasks into a production
job.

These three topics will be treated separately below.

Variety at work
If work is to be done well, there must be a reasonable correlation between
the job and the person doing that job. A job that consists of only a few simple move-
ments and takes only a few seconds to do can certainly be easy to learn. At first sight,
it may seem that this is an eflicient way of organising the work. But this type of job is
hardly efficient from a more practical viewpoint. It will rapidly become monotonous 379
 NEW FORMS OF WORK ORGAN

and tiring, and such extreme specialisation requires long runs, plus a degree of struc-
tural stability and production volume that is not often found in reality. It is much
better to create work roles that display a reasonable amount of variety, that require
something from the worker in terms of learning and that are adapted to reality in
terms of the true length of runs, a stable product mix and infrequent production distur-
bances.
There is no complete, clear answer to the question of how a task cycle that
gives just the right amount of variety should be designed. However, a study of the fol-
lowing factors offers some guidance in bringing about improvements:

the basic structure of the technical system;

the pattern of the physical load;
the information content of the task;
the balance between physical and intellectual task components;
the demand for learning and the need for individual development oppor-
tunities.

In many production technologies the basic structure of the technical system

is the determining factor. For example, on a motor car assembly line the length and
content of the job cycle are wholly dictated by the technical system. If 500 cars are to
be produced in 500 minutes, each operative has one minute in which to do his job.
There is nothing that can be done about it. In other words the job cycle can be
changed only if the concept of the technical system itself (i.e. the assembly line as a
working arrangement) is changed. We shall come back to this question of assembly
system design later.
But the fixed-speed assembly line is not the only technical system that pre-
vents the introduction of a time cycle of reasonable length. Short-cycle man/machine
operations, such as those carried out with eccentric shaft presses, offer another exam-
ple of the need to reshape the entire technical system in order to apply time cycles that
are of a comfortable length for the operative. This also will be discussed later.
It should be emphasised that variety in the time cycle is primarily a subjec-
tive concept and therefore cannot be precisely defined, either technically or
mathematically. However, it is more or less closely related to other factors such as-

length of the time cycle;

size of the run;
frequency of recurrence of a product (that is, the time that passes before the
same product is worked on again);
amount and distribution, in repetitive jobs, of non-repetitive tasks;
differences in work structure and job content between different series.

Example. In an enterprise manufacturing electrical circuit breakers, two

alternatives for the organisation of the work were identified. The first would require
that assembly be done in four separate jobs, each carried out at a specially built and
380 specially equipped work station. At the last of these work stations the assembly work
 NEW FORMS OF WORK ORGANISATION

is completed and a control check is made. In this type of arrangement the cycles are
about ten seconds in length. Variations within cycles are virtually non-existent.
The second alternative would require that the entire circuit breaker assem-
bly be done at each of the work stations (i.e. one job at each work station). In
order to arrive at this solution, the materials supply system would have to be com-
pletely reorganised. By planning the work in this way the cycle is lengthened to 40
seconds. In addiiion, opportunities for varying the cycles increase markedly.
After an analysis of the practical consequences of the two choices at the
workplace, the second alternative was chosen. The decision is significant, since it
exemplifies the efforts that have been made in recent years to limit monotony in jobs
and to achieve a practical balance of working conditions.
One important point in an analysis of this kind is the fact that people are
different. At any one time the people at the sam€ workplace will present quite different
characteristics. And if we study the same person at different times during his working
life, we shall find significant differences in his performance. This is an important, in-
deed fundamental element in the design of individual work roles. Jobs should be dif-
ferent, and should present different degrees of difficulty to those who execute them.
Thus different people can find a work role and a level of difficulty that match their
own aptitudes and preferences. In addition, an individual can begin working in a par-
ticular job that has a particular level of difliculty, and can then move steadily to more
challengingjobs as he develops further.

Decoupling man/machine systems

The rigidity of the links on a worker in a man/machine system may be due
to several factors. The person can be tied to the workplace in a geographical sense-it
may be impossible for him to be absent from his station for even a short time. He can
also be tied by the method-it may be impossible to vary the order in which opera-
tions are carried out. And he can be tied in terms of time-he may be required to
carry out certain operations at fxed times.
The degree of rigidity with which he is tied can be "planned"-that is, the
man and the machine are consciously and deliberately tied together in a man/machine
system-but in many cases the rigidity is quite'ounplanned". In some cases this un-
planned rigidity arises from a fault in the technical system; the operational stability of
the machines may be so poor that the machines must be continuously tended, usually
with only simple movements. Unplanned rigidity can, however, be reduced through
the use of more operationally reliable technology.
Three different types of solution may be offered for this problem of rigid
man/machine links-

(1) Complete decoupling through increased mechanisation.

(2) Use of technical auxiliary equipment to free the operative from the machine.
(3) Decoupling through contact and co-operation among operatives.
Let us examine more closely each of these three choices. 381
 NEW FORMS OF WORK ORGANISATION

Complete decoupling through mechanisation

Decoupling of this kind requires heavy capital investment. Therefore,
production processes that are to be handled in this way must be characterised by mass
production, extremely short cycles and severe rigidity and monotony. In such cases
mechanisation means the complete elimination of all human intervention.

Technical auxiliary equipment for the operator

This principle can be put into effect by establishing buffers and magazines
in an integrated man/machine system in order to reduce dependence relationships
between men and machines. (A buffer is a waiting point located between two con-
secutive operations in the production flow; a magazine is a point of accumulation
located within an operation and providing automatic feeding of material to the
machine.) The key is to create processes that can accept variations in the speed at
which different sections of the line move.
Both buffers and magazines are characterised by an "accumulation of
products for continued processing" which can be completely identical in their
technical design.
Since buffers and magazines are placed at different points in the man/
machine system, their characteristics as accumulators of time are influenced by dif-
ferent types of time gaps in the process.
A buffer makes it possible to accumulate:
(a) the waiting times created when two operatives on opposite sides of the buffer
work at different speeds; and
(b) the waiting times created because the quantities of work done at two stations are
not absolutely identical.

A magazine makes it possible to accumulate:

(a) wutne times created because an operative works at a different speed from the
over-all speed ofthe technical process; and
(b) waitine times created because an operative is forced to wait while a machine does
its part of the work.

Decoupling through contact and co-operation

Finally, decoupling can be achieved if, through job rotation and mutual co-
operation and in agreement with the management, workers are able to interchange
tasks and assignments.

lntegration of production and auxiliary tasks

ln the design of individual work roles it can often be advantageous to
include various service and auxiliary tasks in production jobs. This leads to greater
variety for the individual in his job.
382 Auxiliary tasks that are most often combined in this way are:
 NEW FORMS OF WORK ORGANISATION

maintenance of machines and tools;

setting-up of machines;
handling of materials near the work station;
inventory work;
quality control.

Let us discuss some of these auxiliary tasks further.

When we speak of maintenance in production positions, we are referring to
measures that can be taken to reduce the number and extent of production errors.
Maintenance can include a regular inspection of the system in order to find errors and
take remedial measures. Maintenance can also include repairs of parts so as to make it
possible to achieve the established precision norms required in production. In addi-
tion, it can include a statistical follow-up in order to improve the capacity utilisation of
equipment.
The possibility of including machine setting-up and similar preparatory
functions in the ordinary operative's role depends on a number of factors, among
which are the following:

degree of difficulty and time available for the setting-up operation;

frequency of setting-up operations;
degree of rigidity in other production tasks;
need for special auxiliary equipment to undertake this work.

Example. A metalworking enterprise conducts its operations with the help

of advanced computer-controlled equipment. In one department the operative was
trained to programme the computer equipment himself. He was thus able to handle
the traditional job as well as the programming of the machine tool's computer equip-
ment. He therefore works both as a programmer and as a machine operator. This
example shows that even moderately difficult and specialised tasks can sometimes be
integrated into a normal production job.
Regarding the possible integration of material-handling work near the iork
station, the following factors are some of the more decisive:

character of the product;

volume of materials to be handled;
design of the transport system;
degree of rigidity in the production operation.

These are some examples showing how direct production jobs can be sup-
plemented with various auxiliary and service tasks. There are no simple, standard
solutions in this area; each case must be examined in the light of its special
characteristics. However, the guiding principle in making these decisions is that a
practical and smoothly functioning arrangement must be feasible, that jobs can be
broadened suffrciently to include everyday variations and that they must not be exces-
sively monotonous. 383
 NEW FORMS OF WORK ORGANISATION

3. Design of group work in production

ADVANTAGES OF GROUP WORK
Once individual jobs have been designed, the next logical step is to co-
ordinate these roles. One method of co-ordination that has attracted increasing in-
terest in recent years is the tying together of individual jobs into work groups.
Organisational descriptions of a complete work group specify which roles are included
in the group and the principles according to which these roles should be co-ordinated.
Group work in production can have many advantages. Here we shall touch only on
some of the more important of them.
The most important advantage is the way in which objectives are estab-
lished and the results measured. In this connection it must be borne in mind that it
is much easier to formulate appropriate objectives for a group than for an individual
job, and this is an important advantage.
Another advantage is that the leeway for variations in the individual's acti-
vities increases and that a stronger sense of participation in the larger process can be
experienced than when each person is tied to a limited individual task. People working
in a group have a better chance to co-operate continuously in improving methods and
eliminating unnecessary work. Attitudes can change as team spirit develops.
A further merit of group organisation is that the organisation's capacity to
adapt itself to change increases. An enterprise is in a state of continuous change. The
management alone cannot completely control, manage and follow up this process of
adaptation to change; the organisation itself must possess a strong built-in capacity
for self-adaptation.
These are some of the most important reasons why ideas of group work in
production have been gaining ground in the design of work organisation. But group
work is not suitable everywhere. In certain types of production systems it is an excel-
lent concept, while in others it is completely unworkable. Let us look at some models
of production systems and see how group work might fit with specific working con-
ditions.r

srvErrr PRoDUCTIoN sYsTEM MoDELS:

WHERE DOES GROUP WORK FIT?
We shall divide these production systems schematically into seven main
types, and then use this classification to discuss where group production is most
suitable as an organisational concept. We may refer to these seven models as follows:

(l) The machine-paced line.

(2) The man-paced line.
(3) The automated process.
(a) The concentrated operation.

IThese models are taken from Hans Lindestad and Jan-Peder Norstedt: Autonomous groups and
384 payment by resulr (Stockholm, Swedish Employers'Confederation, 1973).
 NEW FORMS OF WORK ORGANISATION

(5) The diversified line group.

(6) The service group.
(7) The construction group.
Let us study briefly the requisite characteristics for group work in each of
these categories.

The machine-paced line

This type of arrangement is most often found in situations where material
handling is an important factor and where the material-handling function occupies a
dominant role. The classical example of this type is the motor car factory's final
assembly on a fixed-speed assembly line.

Figure 129. Machine-paced line

Operational
limits

Mechanically
controlled material-handling
- systems

In this type of production system a high degree of mechanised handling is

chosen. The flow of materials and the organisation of work are therefore completely
under the control of the technical system. Until only a few years ago this was the only
assembly arrangement used in situations where a high volume of materials was the
rule. The disadvantage of this system is that the individual's work role is strictly
limited and that the work pace is completely controlled by the technical system. In
systems of this type, where operatives are tightly tied to a short task cycle, no genuine
group work is possible. Consequently, the most important disadvantage of such
production systems is the way in which operatives experience their work. Other disad-
vantages include the extreme sensitivity of such lines to disturbances. These produc-
tion chains are only as strong as their weakest link, and it requires only a small in-
fluenza epidemic in the region where the factory is located to upset the whole system.
Moreover, it is difficult to make changes in such production lines. 385
 NEW FORIVS OF WORK ORGANISATION

The advantages are short through-put times, the efficient utilisation of

space, machines and auxiliary equipment and, consequently, the efficient operation
that is achieved through the extreme division of work and specialisation. However,
these advantages apply only when the production system is in operation.
During recent years a considerable number of attempts to'oloosen up" the
assembly line have been made with the help of different innovative arrangements-a
point to which we shall return later.

The man-paced line

If we imagine an assembly line from which we have removed the mecha-
nised control and flow speed and introduced some inventories between work stations,
we have a type of functional arrangement that is common in many companies (in the
clothing and metalworking industries, for example).

Figure 13O. Man-paced line

Material stockpiles
-+
a-
Ia
.-r-
a
:--
a

In this sort of production system the control is less rigorous and the exist-
ence of buffers makes it possible to adapt the individual work pace in a completely
different way from work on an assembly line. In such a system work organisation
based on production groups is an excellent arrangement. Within a group made up of
individual work roles, operatives can help each other, take care of work disturbances,
even out peaks and valleys of work flows and strive for a good common work result.

The automated process

If it were possible to mechanise all the manually executed tasks on a con-
ventional assembly line, the result would be a kind of process line where the indivi-
dual's work would be concerned primarily with supervision and control. Process lines
of this type are extensively used, particularly in the steel, chemical and paper and
386 pulp industries.
 NEW FORMS OF WORK ORGANISATION

On a process line the possibilities of creating meaningful group work are

often excellent. Operatives rely greatly on one another and possess a common goal.
Working together to attain this goal is a clear-cut necessity. One factor that may
sometimes make group co-operation diffrcult is an excessive distance between group
members. A key question in this type of production system is the relationship of direct
production tasks and maintenance tasks executed in the work organisation. The
higher the degree of mechanisation, the fewer production workers there are; but the
number of maintenance workers normally increases at almost the same rate as the
number of production workers decreases.

Figure l3l. Automated process

The concentrated operation (functional layout)

A constant element in the three types of system that we have discussed up
to now is the grouping together of production equipment along the production flow so
that different types of machines are placed in the correct order along the direction of
flow. However, if we group the machines in such a way that all machines of a certain
type are concentrated in one department, all machines of another type in another
department, and so on, we obtain a concentration of each type of operation in one
place (this is the "functional layout" referred to earlier in the book). In this layout the
product to be worked is sent through the various departments in turn-the drilling
department, the turning department the milling department, and so forth.
This type of concentrated operation often occurs in batch production,
where series are short and the products varied.
In this type of production system it is extremely diffrcult to organise
meaningful group work. In everyday reality each individual is bound to his own in-
dividual job and work station. Genuine group work with spontaneous interaction
between different roles and role occupants is virtually impossible to bring about. 387
 NEW FORMS OF WOBK ORGANISATION

Figure 132. Concentrated operation

The diversified !ine group

In many cases the conditions affecting production are such that neither
highly developed line grouping nor an advanced degree of operation grouping is
suitable. Instead, an intermediate type is chosen-what we may call the "diversified
line group". Production is concentrated in an arrangement that is primarily flow-
oriented, but in order that it may carry out many combinations of tasks, some critical
operational stages are repeated two or more times. In this way a system is obtained
that can, with a high degree of efficiency, combine the capacity of the flow group to
accept and channel a large volume of materials with the capacity of the functional
layout to execute all conceivable production assignments.
In this type of production system, group work is often an excellent
organisational concept. With this arrangement the division of work between various
individuals must be adapted continuously to varying conditions. But this cannot be
done entirely by the management, and a substantial proportion must occur spon-
taneously at the initiative of the members of the group. In a group organisation the
capacity for such spontaneous self-adaptation can gradually be generated.

The service group

Conditions within service-producing organisations differ in several respects
from the types of activity we have discussed earlier. Various forms of services are
produced in large sectors, such as commerce, transportation, hotels and restaurants
and motor vehicle repair shops. But service functions also occur in manufacturing in-
dustry, a good example being repair and maintenance activities.
The service functions of a production unit must be highly adaptable to vary-
ing demands. Generally, the tasks to be done vary in nature. The work load is uneven
388 and it is diflicult to plan the work in detail.
 NEW FORMS OF WORK ORGANISATION

Figure 133. Service group

Group organisation is a good concept in this type of situation also. The

work group can itself handle much of the variation that shows up in the inflow of
tasks, in routine work planning and in other circumstances that tend to vary.

The construction group

For the flrnal type in our classification, let us see how construction opera-
tions are carried out. In this case the product itself is the centre for the whole organisa-
tion, which is built up around the construction object itself. Work organisations of this
type are also found in industry, for example in manufacturing very large products (e.g.
turbines, ships, process machinery).

Figure 134. Construction grouP

389
 In production work of this type, group work is not only a good idea: it is the
only conceivable type of work organisation. Moreover, the work is varied, and the
spontaneous adaptation of the division of work and planning is such an essential
feature that flexible group organisation is the only possible solution.

We have now briefly examined the possibilities of group work in different types of
production system. We have seen that group work is more suitable in some cases than
in others.
One of the lines of development that has been particularly advocated in dis-
cussions about group work in production is the degree to which groups can be
organised along the direction of production flow. Grouping of this type makes it poss-
ible to direct the group's interests and strivings toward a good common production
result. We might look rather more closely at the possibilities of organising such
groups, either in assembly work or in machine shops. Our purpose in taking up these
examples for special discussion is not to provide ready-made solutions but to point out
a line of development that nowadays is assuming particular importance.

FLOW GROUPS IN ASSEMBLY WORK:

SOME TRENDS AND EXAMPLES

In assembly work, flow groups have always been the most natural arrange-
ment. Let us take linal assembly of a motor car, for example. When this arrangement
was first conceived it was quite natural to introduce an assembly system that moved
beside a materials inventory, with the different components being assembled on the
car as it moved past. This is an extreme example of flow orientation in assembly work.
The flow of materials was completely decisive in arranging the work.
But an arrangement of this type can also have its disadvantages. The work
is strictly controlled and the cycle time is normally very short.
At subsequent stages of development, efforts were made to introduce buf-
fers in the production line in order to create greater freedom in different parts of the
production system. This placed new demands on the system, and various technical
solutions were advocated to separate the different links in the chain from each other.
With reference to our previous discussion of different production system
models, we may say that the introduction of buffer arrangements in motor car assem-
o'machine-paced line" to a "man-paced
bly changes the production system from a
line". The following is an example from a newly constructed motor car engine factory.

Assembly of motor car engines

The assembiy process can be summarised as follows. Seven assembly
groups are organised beside an automatic transportation track loop. Except for cer-
tain steps which are handled before the loop stage, complete engines are assembled in
each group.

Up to six engines can be assembled at the same time within each production
group. During the assembly itself there is no mechanised control of the flow as in a
390 moving assembly line. Engines are moved manually while being assembled. When an
 NEW FORMS OF WORK ORGANISATION

Figure 135. Assembly of motor car engines

"Lighter" components
are distributed
direct to assembly
groups
Assembly groups

clocks, crankshafts and

:omponents are placed
ransport trolleys
rove along the track

Assembly trolleYs

engine has been completely assembled in a group, it is transported automatically to a

testing station which is common to all groups. At the same time it is automatically
registered that an engine has left the group and a new assembly trolley is moved
forward to that group on the transport track.
The advantages and disadvantages of this type of assembly process, as
compared with the traditional assembly line, are as follows:

(l) This arrangement is more flexible and less susceptible to interruptions and fluctua-
tions in the production flow.
(2) It offers good possibilities for job expansion and a more stimulating kind of group
work. Each of the small loops contains a production group, a'ogang" whose
members co-operate closely in everyday tasks and themselves take care of such
chores as the adaptation of work to changing conditions. One of the seven groups
is a training group. In this group there is a fairly strict and extensive division of
tasks based on detailed instructions. In the other groups the division of work is
made on the basis of the abilities of individual members. There is therefore an
opportunity to adapt the design of jobs within the group to the workers' knowl-
edge and experience.
(3) It is not necessary to carry out an extensive and costly reconstruction ofthe line
every time the production volume has to be increased or decreased. Capacity can
be expanded to a certain extent by varying the numbers of members in the groups,
up to six. Further increases in capacity can be achieved by increasing the number
ofgroups.
(a) Job design is better adapted to the individual and should therefore lead to better
recruiting possibilities, reduced personnel turnover and less absenteeism.
(5) The new arrangement requires greater floor space and higher goods-in-process
inventories than a moving assembly line. 391
 NEW FORMS OF WO8K ORGANISATION

(6) Capital investment is somewhat higher for the new arrangement.

(7) Work efliciency (primarily as regards speed of movement) is lower than on a mov-
ing assembly line, because of the lower degree of specialisation and the fragmenta-
tion of work assignments.

This example illustrates not only how buffer arrangements can be intro-
duced between different jobs and different capacities for work of different indi-
viduals but also how different parts of an assembly line-or an entire line-can be
rearranged in a parallel pattern. The assembly of the engines is carried out at a
number of stations, with an entire engine being assembled at each station.
The nature of parallel production operations is made clear in figure 136.

Figure 136. Line grouping and parallel grouping

Line grouping

Parallel grouping

The most important advantages offered by the parallel arrangement of an

assembly operation (or parts of an assembly operation) are as follows:

(l) Production reliability-it is naturally less likely that several subsystems will all be
simultaneously affected by disturbances than that one large system will be so
aflected.
(2) Flexibility-it is easier to handle different product models, as well as changes in
production volume, in a parallel system.
(3) Work content and work organisation-the possibility of creating tasks with a
richer content, and of finding natural dividing lines between groups, is con-
siderably greater. Opportunities for production groups to accept responsibility for
392 quality and the division of work, for example, are also greater.
 NEW FORMS OF WORK ORGANISATION

Flow-oriented machine groups in batch production

In a traditional layout in batch production, machines and personnel are

grouped in departments, with each department carrying out its own separate function.
For example, one department may handle turning, another drilling, a third milling, and
so on. The advantage of this arrangement is that it results in great flexibility and a
high degree of utilisation of machine capacity. A major disadvantage is that the
volume of goods-in-process, and therefore the amount of working capital tied up in
these goods, is always substantial. Moreover, the work in a plant of this kind is highly
fragmented. It is difficult for an individual or a group of individuals to see the connec-
tion between their own work roles and the over-all activity of the company. It is
therefore diffrcult for individuals and groups to participate actively in work planning
and in attaining the established goals of the company.
During recent years, interest has grown in finding ways of grouping
machinery and equipment around flow-oriented groups in batch production, that is,
groups formed around the manufacture of entire products or complex product com-
ponents. We shall discuss these trends briefly here.
What is a flow-oriented group? Figure 137 illustrates the basic principle.
With the help of a standard classification method, we have selected an
assortment of different components, such as axles and flanges. In each of these groups
there are subgroups that resemble each other as regards the types ofwork required.
Machines, personnel and other resources needed for the components-from metal
supplies to finished parts-are collected in one unit. Through the choice of suitable
components, methods and equipment we can create a simple flow pattern.
With this manufacturing arrangement through-put times, and therefore also
the working capital tied up in the system, can both be reduced. Production can be car-
ried out with a minimum of supplies of materials on hand-this applies particularly to
the work stations themselves. The lower the supply of materials on hand, the shorter
and surer the through-put times become.
In a functional organisation, each operative's task at oohis" machine and the
job planned for the machine are fxed in advance. A flow-oriented group is a machine
group for the finished manufacture of a mix of components. It contains more
machines or work stations than there are operatives, and each operative should
preferably master several types of job. This means that all the members of the group
must be able to work relatively independently. The group members themselves have
the responsibility for dividing the work between them and seeing that material flows
through the group as it should. Thus the work of a flow group relies heavily on
teamwork and co-operation.
Unlike a functional grouping of machines, a flow group makes heavy
demands on individuals. But a flow group also makes possible the creation of more
attractive work roles for group members, because-

(1) They have a better over-all view of their contribution to the larger production
process.
(2) They have more variety in their work because they can move between various
tasks. 393
 NEW FORMS OF WOBK ORGANISATION

Figure 137. Schematic diagram of a flow-oriented group

Et EItr'

E [tr

@ @)

mffi &&
(3) They have the chance of being trained for new jobs.
(4) They have increased contact with their colleagues at work as well as with the
management.

Example.In figure 138, a flow group has been created for the manufacture
of pump ades in a metalworking company. In this group approximately 150 types of
axle are produced; however, these are based on about ten general methods, of which
the most widely used account for about 65 articles.
The simplest components are manufactured from pre-cut metal pieces dur-
ing a single trip through the group. The most complicated components must go
through the group three times. Operatives can easily return parts to the incoming sta-
tion with the help of roller conveyor tracks. Two men work in this group; their work is
delineated by the shape ofthe conveyor.
However, flow-oriented manufacturing in short series requires certain
definite conditions and cannot be used in all situations. For example, a systematic
394 structuring of the product mix must be made, to make it possible to channel certain
 NEW FORMS OF WORK ORGANISATION

Figure 138. Flow group for the manufacture of pump axles

Numerically

E
lathe

ilin I u T{
-il- Key-seating milling
I machine
,-
h'
it= UnE;
i.on,.o, r
t
I
I Elevator
I F<__\_-
Station for \
outgoing I \
materials
=--:::-l=l$
--- \i^ t

Radial milling \
Milling machine machine \\
E
ffi
Support

I -r

Station for
incoming
materials
395
 IISATION

main types of product in a homogeneous flow. Moreover, production must be of such

a nature that an "unbroken flow principle" can be applied. Ifit is necessary to break
the material flow within the flow group at a certain operational step and to send com-
ponents outside the group for working, the planning will naturally become substan-
tially more complicated.
A key issue in the formation of flow-oriented groups is the degree of utilisa-
tion of equipment that can be attained, especially in the case of more expensive
production machinery. Here it is necessary to weigh machine costs against the costs
of tying up capital in everyday work. Recently, the clear trend is towards a recogni-
tion of the fact that tying up capital in goods-in-process inventories has reached such
proportions that the order of priorities has had to be modified in favour of the use of
flow groups.
A further factor of decisive importance is of course the stability of the
product mix. Flow grouping of machinery has to be based on the assumption that it is
possible to foresee that a certain product or product component will be manufactured
in a certain form and according to certain methods. In cases where there is some un-
certainty about these factors, flow grouping is not possible.
In conclusion, we may again emphasise the fact that, in batch production,
there are often excellent reasons for choosing flow grouping of machinery and
operatives rather than functional grouping. The main reasons are that, in practice,
functional grouping is difficult to cope with from an administrative point of view, that
substantial amounts of goods-in-process tie up considerable working capital and that
jobs in a functional shop tend to be boring and monotonous for workers.

4. Design of product-oriented organisations

THE COMPANY WITHIN THE COMPANY
The concept of product-oriented organisations as a method of structuring
production in batch manufacturing is becoming increasingly common. The conven-
tional method of organising production of this type has been in functional shops or
departments, that is, where machines with similar functions are grouped together.
In this arrangement, precisely the opposite direction is taken. A product-
oriented organisation may be defined as a production unit which is organised and
equipped in such a way that it can independently manufacture a certain finished
product or family of products. To put it another way, the aim is to group together,
physically as well as administratively, the entire production chain for a specific
product or group ofproducts.
With reference to the previous discussion of flow groups in batch produc-
tion, we can say that this is an organisational solution which follows the same prin-
ciple not only as regards production but also at the organisational level. A product-
oriented organisation is a larger unit than a flow group, manufactures more complex
products or product components and can consist ofseveral flow groups.
A product-oriented organisation should be able to function rather as a com-
pany within a company. This means that it must occupy an independent position vis-
396 i-vis its environment. Complete manufacturing resources should be found so that the
 NEW FORMS OF WORK ORGANISATION

complete manufacturing chain can be handled from beginning to end for a certain
product or product component. It should also have its own administrative resources
and its own operating services, such as maintenance, material handling, and so on.
By locating complete manufacturing resources within the plant so that the
entire production chain can be held together in one place, there is very litfle
dependlnce on other units and the co-ordination of products can be taken care of
within the organisation. In this way a simple planning process and short through-put
times can be attained. The unit can also be truly independent with regard to other
working areas in the immediate vicinity.
If this method is to work properly, however, all the machinery necessary to
carry out the complete production operation must be available. In general, the
capacity of utilisation of most machines will be lower than in a functional shop. The
possible machine utilisation will thus be a key factor in examining the feasibility of this
organisational concept, and should be weighed against its other advantages, especially
as regards lower working capital tied up in inventories and simpler administration.

FLOW PATTERNS IN A PRODUCT-ORIENTED

AN EXAMPLE
ORGANTSATION :

By defrnition, the product-oriented organisation refers to a certain flow of

production. Within the unit itself, however, this flow can be more or less divided, and
machine grouping can vary from very pronounced line grouping to a more
operationally grouped functional arrangement. Let us look at two examples of the
organisation of a product shoP.
In the first example, a heat exchanger unit, a systematic attempt has been
made to build the production structure on the basis of flow groups. It proved possible
to do so for the main part of the manufacturing process despite the fact that it is
heavily influenced by customer orders and that batches are small. Figure 139 shows
how an attempt was made to come as near as possible to a "straight-line" arrange-
ment. This simplifies material handling and gives all operatives a good over-all
view of the manufacturing process.
However, it will be seen that the flow is divided between two areas in the
manufacturing chain. There is a materials buffer for assemblY, and there is also a buf-
fer between the pressing of plates and finishing of products (see figure 140). The
reason for this is to achieve reasonable batch sizes and to reduce change-over times in
production.
In our second example, relating to the manufacture of electric motors, figure
141 shows a product-oriented organisation consisting of a number of flow groups in
which different components are manufactured. Among the principles on which the
arrangement was based are the following:

(1) Manufacture of components in units from raw materials, each in its own compo-
nent flow or flow grouP.
(2) Co-ordination of component flow directly ivith the main flow without material
buffers or interim inventories.
(3) Completion of main flow with delivery of finished motors. 397
 NEW FORMS OF WORK ORGANISATION

Figure 139. Layout for a heat exchanger unit

lnventory Buffer

Finished manufacture

Manufacture of components

This arrangement of the flow means that the quantity of goods-in-process is

very small, and the through-put times from the first operation to the finished motor is
only two or three days. Furthermore, no interim inventories are needed for assembly.

5. Criteria of good work organisation: some concluding remarks

EFFICIENCY
The first and most fundamental criterion of good work organisation is, of
course, that it should be effective-that the use of resources should be maximised and
that the largest possible output should be obtained from the smallest possible input.
The various chapters of this book have dealt extensively with this criterion, because
this factor will always be of fundamental significance-in all types of technology, in
all stages of development and at every workplace.
Naturally, there are situations in which considerations other than those of a
purely economic nature are of paramount importance. If, for example, there are evi-
398 dent safety or health risks at a workplace, and if additional investment is required to
 NEW FOHMS OF WORK ORGANISATION

Figure l4O. Some examples of the building of buffer stock in manufacturing operations

Sketch of a typical magazine Sketch of a work station with a simple

sliding rack or storage space

Sketch of a high-stacking machine

used as a buffer

Sketch of a buffering track 399

 NEW FORMS OF WORK OBGANISATION

Figure 141. Manufacture of electric motors

Raw materials

a
o
o
I

3
g.

=
o
{

Finished goods

eliminate them, the appropriate steps to do so must be taken even if it is not possible
to point to any demonstrable economic profitability resulting directly from such mea-
sures. This is an example of how economic considerations (at least in the short term)
have to give way to other factors.
But, notwithstanding special cases such as this where particular circum-
stances obtain, economic considerations must inevitably be of fundamental impor-
tance in the choice of a suitable form of work organisation. The organisational prin-
ciples and solutions that result both in increased efficiency and in better jobs for the
workers are naturally to be preferred.
AUTONOMY OF SMALL SYSTEMS
Even if economic considerations are of fundamental significance and must be
carefully analysed in each individual case, there are several rules of thumb, or general
lines of thinking, for the construction of a good production system-guidelines that
have become increasingly important during recent years in the development of new
forms of work organisation but in which precise calculations of short-term
proflrtability are diflicult, if not impossible. Nevertheless, there has been so much
emphasis on these guidelines that we take special note of them here; but we must also
400 stress that they stand somewhat apart from the basic economic factors.
 NEW FOBMS OF WORK ORGANISATION

The first of these criteria for constructing good production systems is the
search for greater independence for small systems in company organisation. By this
we mean production systems that consist of moderately large production units and
can function with a relatively high degree of independence within the larger company.
The underlying intention is to create a production arrangement that emphasises local
independence within smaller units. Breaking down the company into these smaller
units reduces the need for co-ordination, and therefore management problems too
become simpler to deal with.
The decentralisation that results from this type of production arrangement
is also of great value in stimulating local initiative and in increasing the ability to adapt
to the changing conditions and needs that arise in different parts of the company. It
has also been shown that workers are often more satisfied and more involved in their
work if they are members of smaller and more independent production units.
If we wish to create production systems based on this principle, four points
are particularly significant-

(1) The possibility of dividing up larger systems into smaller systems.

(2) The possibility of arranging finished manufacturing units into smaller units so that
the need for contacts with adjacent units is reduced.
(3) The possibility of arranging for self-suffrciency as regards production resources,
operational service, and so on.
(4) The possibility of arranging for less direct management control from high levels,
so that the independence of the smaller units is not eroded too much by control
from the upper levels ofthe hierarchy.

STABILITY OF THE PRODUCTION SYSTEM

One further rule of thumb or criterion of a good production system which
has received increasing interest in recent years is the desire to arrange for stable
production activity with a minimum of disturbance. The following requirements in
particular arise in this connection:

(l) A simple flow pattern, so that as far as possible the workers have an over-all view
and that it becomes easier to plan the work.
(2) An operationally reliable technology with an optimum level of mechanisation, so
that technical disturbances are held within reasonable limits.
(3) A disturbance-resistant work arrangement, so that all production stages that are
critical for production are organised in parallel and that those that are particularly
sensitive to disturbance are surrounded with buffers of different kinds.

AfiRACTIVE JOBS
It is important to be able to offer people jobs that they find attractive and in
which they can feel personally involved. Personal aspirations vary from individual to
individual and from situation to situation, and depend not only on a person's ambi-
tions and desires but also on his or her abilities, knowledge and capacity to develop. A
production organisation must therefore offer a variety ofjobs, so that the desires of as 401
 many people as possible can be satisfied and so that a particular individual can
progress from simple jobs to more complex work roles.
Among the factors that should be considered in any endeavour to create
suffrciently attractive jobs are the following:
(l) The creation of jobs with different degrees of diffrculty through flow orientation,
different degrees of subdivision of work and different degrees of integration of
auxiliary tasks. Variations of this kind make it possible to offer to different in-
dividuals at different times jobs that correspond to their abilities and wishes.
(2) The creation of individual jobs and group arrangements that bring about a degree
of independence in work, through finished manufacturing of entire products, self-
sufficiency of production service functions and buffering vis-i-vis adjacent
systems. This independence is of value both in terms of the production results
obtained and for the way the work is experienced by individuals in the group.
(3) The design of a work organisation that is suitable for teamwork,as a result of flow
grouping and similar arrangements that are compatible not only with more attrac-
tive jobs and work situations but also with greater efficiency.
(4) Provision of over-all views from inside the organisation. In order for a person to
find his work attractive, he must also be able to view the larger context of which
his work is a part. It is also important that he should be involved, if possible, in the
design of his work and be able to feel some sense of 'obelonging" with his group of
fellow workers and with the over-all production process in which he performs his
function.

GOOD WORKING ENVIRONMENTS

An important criterion of a good job is the quality of the working environ-
ment. In Chapter 6 we indicated the basic factors that have to be considered with
respect to safety at the workplace.
In addition,however, a working envkonment should also be pleasant to
work in-in other words, it should be so designed that it becomes easier to adopt
ergonomically correct working positions.

CONCLUSION
We have briefly touched on some of the trends leading towards new forms
of work organisation. We have given some principles and general guidelines. We
have provided some examples and emphasised certain current lines of development.
Finally, we have given some criteria to be borne in mind when designing good work-
ing environments.
It is important, however, to stress the fact that there are no standard solu-
tions to these problems. Our aim has been merely to put forward a few ideas, tenden-
cies and general indications of solutions to problems. It must be remembered that the
best solution to a problem can be found only in the specific circumstances of the par-
ticular case-when the actual conditions are known, when local values are considered
402 and when the persons involved are able to find tleir own solutions.
 Part live
Appendices
r. Glossaryof terms used

A. Work study
Activity Sampling (ChaPter l4)
See Work SamPling.

Basic Time (CiaPter 18)

The time for carrying out an element of work at standard rating, i'e'-
Observed Time x Observed Rating
Standard Rating

Break Point (Chapter 16)

The instant at which one element in a work cycle ends and another begins.

Check Time (Chapter 18)

The time intervals between the start of a time study and the start of the flrrst element observed,
and between the hnish of the last element observed and the finish of the study.

Chronocyclegnph (Chapter 1 I )
A cyclegraph in which the light source is suitably intemrpted so that the path appears as a
series of pear-shaped dots, the pointed end indicating the direction of movement and the spacing in-
dicating the speed of movement.

Contingency Allowance (Chapter I 8)

A small allowance of time which may be included in a standard time to meet legitimate and
expected items of work or delays, the precise measurement of which is uneconomical because of their
inflrequent or irregular occurrence.

Cumulative Timing (Chapter 16)

See Timing.

Cyclegraph (Chapter I I )
A record of a path of movemen! usually traced by a continuous source of light on a
photograph, preferably stereoscopic.

Cycle Time (Chapter 20)

The total time taken to complete the elements constituting the work cycle.

Elapsed Time (Chapter 16)

The total time from the start to the flrnish of a time study. 405
 Element (Chapter l6)
A distinct part of a specified job selected for convenience of observation, measurement and
analysis.

Constant Element
An element for which the basic time remains constant whenever it is performed.

Foreign Element
An element observed during a study which, after analysis, is not found to be a necessary part
ot the job.

Governing Element
An element occupying a longer time than that of any other element which is being perlormed
concurrently.

Machine Element
An element automatically performed by a power-driven machine (or process).

Manual Element
An element perlormed by a worker.

Occasional Element
An element which does not occur in every work cycle of the job, but which may occur at
regular or irregular intervals.

Repetitive Element
An element which occurs in every work cycle of the job.

Variable Element
An element for which the basic time varies in relation to some characteristics of the product,
equipment or process, e.g. dimensions, weighto quality, etc.

Extension (Chapter 18)

The calculation of basic time from observed time.

Fatigue Allowance (Chapter 18)

A subdivision of the relaxation allowance intended to cater for the physiological and
psychological effects of carrying out specihed work under specihed conditions.

Film Analysis (Chapter 11)

The frame-by-frame examination of a cin6 flrlm of an operation to determine the state of
activity ofthe subject during each exposure.

Flow Diagram (Chapter 7)

A diagram or model, substantially to scale, which shows the location of specific activities
carried out and the routes followed by workers, materials or equipment in their execution.

Flow Process Cha*(Chapter 8)

A process chart setting out the sequence ofthe flow ofa product or a procedure by recording
all events under review using the appropriate process chart symbols.

Equipment Type Flow Process Chart

406 A flow process chart which records how the equipment is used.
 .1
APPENDIX

Man Type Flow Process Chart

A flow process chart which records what the worker does.

Material Type Flow Process Chart

A flow process chart which records how material is handled or treated.

Flyback Timing (Chapter 16)

See Timing.

Idle Time (Chapter 2)

That part of attendance time when the worker has work available but does not do it.

Ineffective Time (Chapter 2)

That portion of the elapsed time, excluding the check time, spent on any activity which is not
a specified part of a job.

Inside Work (Chapter 19)

Elements which can be performed by a worker within the machine- (or process-)controlled
time.

Interference Allowance (Chapter I 9)

An allowance of time for production unavoidably lost through synchronisation of stoppages
on two or more machines (or processes) attended by one worker. Similar circumstances arise in team
work.

Interference Time (Chapter 19)

The time when the machinle (or process) is idle awaiting attention, while the worker attends to
another machine (or process). Similar circumstances arise in team work.

Job Breakdown (Chapter 16)

A listing of the content of a job by elements.

Load Factor (Cft apter I 9)

The proportion of the over-all cycle time required by the worker to carry out the necessary
work at standard performance, during a machine- (or process-)controlled cycle.

Machine Ancillary Time (Chapter 19)

The time when a machine is temporarily out of productive use owing to change-overs, setting,
cleaning, etc.

Machine Available Time (Chapter 19)

The time which a machine could work based on attendance time-i.e. working day or week
plus overtime.

Machine Capacity (Chapter 19)

The potential volume of a machine, usually expressed in physical units capable of being
produced in any convenient unit oftime, e.g. tons per week, pieces per hour, etc.

Machine-Controlled Time (Chapter I 9)

The time taken to complete that part of the work cycle which is determined only by technical
factors peculiar to the machine. 4O7
 Machine Down Time (Chapter 19)
The time during which a machine cannot be operated on production or ancillary work owing
to breakdown, maintenance requirements, or lor other similar reasons.

Machine Effective Utilisation lndex (Chapter l9)

The ratio oft Machine Running Time at Standard
to: Machine Available Time.

Machine Efficiency lndex (Chapter 19)

The ratio of: Machine Running Time at Standard
to: Machine Running Time.

Machine How (Chapter 22)

The running of a machine or piece of plant for one hour.

Machine Idle Time (Chapter l9)

The time during which a machine is available for production or ancillary work but is not used
owing to shortage of work, materials or workers, including the time that the plant is out of balance.

Machine Interference (Chapter 19)

The queuing of machines (or processes) for attention-e.g. when one worker is responsible
for attending to more than one machine. Similar circumstances arise in team work where random
delays at any point may affect the output of the team.

Machine Maximum Time (Chapter 19)

The maximum possible time during which a machine or group of machines could work within
a given period, e.g. I 68 hours in one week
or 24 hours in one day.

Machine Running Time (Chapter 19)

The time during which a machine is actually operating, i.e. the machine available time /ess
any machine down time, machine idle time, or machine ancillary time.

Machine Running Time at Standard (Chapter 19)

The running time that should be incurred in producing the output if the machine is working
under optimum conditions.

Machine Utilisation lndex (Chapter 19)

The ratio oft Machine Running Time.
to: Machine Available Time.
Man-Hour (Chapter 2)
The labour of one man for one hour.

Memomotion Photography (Chapter I I)

A form of time-lapse photography which records activity by a cin6 camera adapted to take
pictures at longer intervals than normal. The time intervals usually lie between Yz and 4 seconds.

Method Study (Chapter 4)

The systematic recording and critical examination of existing and proposed ways of doing
work, as a means of developing and applying easier. and more effective methods and reducing costs.

Methods-Time Measurement (MTM) (Chapter 21)

408 A system of Predetermined Time Standards (q.v.).
 APPENDIX 1

Micromotion Srudy (Chapter 1l)

The critical examination of a simo chart prepared by a frame-by-frame examination ol a cin6
film of an operation.

Multiple Activity Chart (Chapter I 0)

A chart on which the activities of more than one subject (worker, machine or item of
equipment) are each recorded on a common time scale to show their inter-relationship.

Multiple Machine Work (Chapter 19)

Work which requires the worker to attend two or more machines (of similar or different
kinds) running simultaneously.

Observed Time (Chapter t7)

The time taken to perform an element or combination of elements obtained by means of
direct measurement.

Outline Process Chatt (ChaPter 8)

A process chart giving an over-all picture by recording in sequence only the main operations
and inspections.

Outside Work (Chapter 19)

Elements which must necessarily be performed by a worker outside the machine- (or
process-)controlled time.

Personal Needs Allowance (Chapter l8)

A subdivision of the relaxation allowance intended to cater for attention to personal needs.

Plant and Machine Control (Chapter 19)

The procedures and means by which efficiency and utilisation of units of plant and
machinery are planned and checked.

Policy Allowance (Chapter I8)

An increment, other than bonus increment, applied to standard time (or to some constituent
part of it, e.g. work content) to provide a satisfactory level of earnings for a specified level of perfor-
mance under exceptional circumstances.

Predetermined Time Standards (PTS) (Chapter 21)

A work measurement technique whereby times established for basic human motions (clas-
sihed according to the nature of the motion and the conditions under which it is made) are used to build
up the time flor a job at a defined level of performance.

Primary Questions (Chapter 8)

The first stage of the questioning technique, which queries the fundamental need for the per-
formance, place, sequence, person and means of every activity recorded, and seeks a reason for each
reply.

Principles of Motion Economy (Chapter l1)

Characteristics which, when incorporated in the methods adopted, make for easier working.

Process Charls (Chapter 8)

Charts in which a sequence of events is portrayed diagrammatically by means of a set of
process chart symbols to help a person to visualise a process as a means of examining and improving it. 4Og
 Process-Controlled Time (Chapter I 9)
The time taken to complete that part of the work cycle which is determined only by technical
factors peculiar to the process.

Qualified Worker (Chapter 16)

One who is accepted as having the necessary physical attributes, who possesses the required
intelligence and education, and who has acquired the necessary skill and knowledge to carry out the
work in hand to satisfactory standards of safety, quantity and quality.
Questioning Technique (Chapter 8)
The means by which the critical examination is conducted, each activity being subjected in
turn to a systematic and progressive series of questions.
Random Observation Method (Chapter 14)
See l4tork Sampling.
Rating(Chapter l7)
( l) The assessment of the worker's rate of working relative to the observer's concept of the rate
corresponding to standard pace.
(2) The numerical value or symbol used to denote the rate of working.
(a) Loose rating: an inaccurate rating which is too high.
(b) Tight rating: an inaccurate rating which is too low.
(c) Inconsistent ratings: a mixture ofloose, tight and accurate ratings.
(d) Flat ratings: a set of ratings in which the observer has underestimated the variations in
the worker's rate of working.
(e) Steep ratings: a set of ratings in which the observer has overestimated the variations in
the worker's rate of working.
Rating Scale (Chapter 17)
The series of numerical indices given to various rates of working. The scale is linear.
Ratio-Delay Study (Chapter l4)
See Work Sampling.
Relaxation Allowance (Chapter 18)
An addition to the basic time intended to provide the worker with the opportunity to recover
from the physiological and psychological effects of carrying out specihed work under specified condi-
tions and to allow attention to personal needs. The amount of the allowance will depend on the nature
of the job.

Representative Worker (Chapter I 7)

A worker whose skill and performance is the average of a group under consideration. He is
not necessarily a qualified worker.

Restricted WorJr (ChaPter 19)

Work in which the output of the worker is limited by factors outside the control of the
worker.
Secondary Questions (Chapter 8)
The second stage of the questioning technique, during which the answers to the primary ques-
tions are subjected to further query to determine whether possible alternatives of place, sequence,
persons and/or means are practicable and preferable as a means of improvement upon the existing
method.
Selected Time (Chapter 18)
The time chosen as being representative of a group of times for an element or group of ele-
ments. These times may be either observed or basic and should be denoted as selected observed or
41O selected basic times.
 APPENDIX 1

Setting-Up Time (Chapter 19)

The time required to prepare a machine for work. It includes the removal of tools used for the
previous tasks, any necessary cleaning of the machine, and the fixing of tools and fixtures for the new
iob.

Simultaneous Motion Cycle Chart ("Simo Chart') (Chapter 1l)

A chart, often based on film analysis, used to record simultaneously on a common time scale
the therbligs or groups of therbligs performed by different parts of the body of one or more workers.

Snap-Reading Method (Chapter I4)

See Work Sampling.

Standard Data (Chapter 22)

Tables and lormulae derived from the analysis of accumulated work measurement data,
arranged in a form suitable for building up standard times, machine process times, etc., by synthesis.

Standard Performance (Chapter l7)

The rate of output which qualihed workers will naturally achieve without over-exertion as an
average over the working day or shift, provided that they know and adhere to the specified method and
provided that they are motivated to apply themselves to their work. This performance is denoted as 100
on the standard rating and performance scales.

Standard Time (Chapter 18)

The total time in which a job should be completed at standard performance, i.e. work contento
contingency allowance for delay, unoccupied time and interference allowance, where applicable.

String Diagram (Chapter I0)

A scale plan or model on which a thread is used to trace and measure the path ofworkers,
material or equipment during a specified sequence of events.

Therblig (Chapter I l)
The name given by Frank B. Gilbreth to each of the specific divisions of movement, accord-
ing to the purpose for which it is made. These therbligs cover movements or reasons for absence of
movement. Each therblig has a specific colour, symbol and letter for recording purposes.

Time Study (Chapter 15)

A work measurement technique for recording the times and rates of working for the elements
of a specified job carried out under specified conditions, and for analysing the data so as to obtain the
time necessary for carrying out the job at a defined level of performance.

Timing (Chapter 16)

The practice of observing and recording, by the use of a watch or other device, the time taken
to complete each element. Three alternative methods of timing with a stop-watch are:

Cumulative Timing
A method in which the hands of the stop-watch are allowed to continue to move without
returning them to zero at the end of each element, the time for each element being obtained
subsequently by subtraction.

Differential Timing
A method for obtaining the time of one or more small elements. Elements are timed in
groups, first including and then excluding each small elemento the time for each element being
obtained subsequently by subtraction. 41 1
 APPENOIX 1

Flyback Timing
A method in which the hands of the stop-watch are returned to zero at the end of each ele-
ment and are allowed to restart immediately, the time for the element being obtained directly.

Tool Allowance (Chapter l8)

An allowance of time, which may be included in a standard time, to cover adjustment and
maintenance of tools.

Travel Chart (Chapter 10)

A tabular record for presenting quantitative data about the movements of workers, materials
or equipment between any number of places over any given period of time.

Two-Handed Process Chart (Chapter 11)

A process chart in which the activities of a worker's hands (or limbs) are recorded in their
relationship to one another.

Unoccupied Time (Chapter 19)

The periods during machine- (or process-)controlled time when a worker is engaged neither
on inside work nor in taking authorised rest, the time for carrying out the work being calculated at a
defined performance.

UnoccupiedTime Allowance (Chapter I 9)

An allowance made to a worker when there is unoccupied time during machine- (or process-)
controlled time.

Unrestricted Work (Chapter 19)

Work in which the output of the worker is limited only by factors within the control of the
worker.

Work Content (Chapter 18)

Basic time + relaxation allowance + any allowance for additional work-e.g. that part of
contingency allowance which represents work.

Work Cycle (Cftapter 16)

The sequence of elements which are required to perform a job or yield a unit of production.
The sequence may sometimes include occasional elements.

Work Factor (Chapter 21)

A system of Predetermined Time Standards (q.v.).

Work Measurement (Chapter 4)

The application of techniques designed to establish the time for a qualified worker to carry
out a specified job at a dehned level of performance.

Work Sampline (Chapter I 4)

A method of finding the percentage occurrence of a certain activity by statistical sampling
and random observations. (Work sampling is also known as ratio-delay study; observation ratio study;
snap-reading method; random observation method; and activity sampling.)

Work Specific ation (Chapter 23 )

document setting out the details of an operation or job, how it is to be performed, the
A
layout of the workplace, particulars of machines, tools and appliances to be used, and the duties and
responsibilities of the worker. The standard time or allowed time assigned to the job is normally in-
412 cluded.
Work Study (Chapter 4)
A generic term for those techniques, particularly method study and work measurement,
which are used in the examination of human work in all its contexts, and which lead systematically to
the investigation of all the lactors which affect the efliciency and economy of the situation being
reviewed, in order to effect improvement.

B. Plant layout
Factory Flow Analysis
Part of production flow analysis (q.v). A technique which uses networks to study and
simplify the flow of materials between departments.

Fixture
A device tor holding parts which would otherwise have to be held in one hand while the other
worked on them.

Group Analysis
Part of production flow analysis (q.v). A technique used to determine the best division of the
machines in a machining department into groups and the best division of the parts made into families.

Group Layout
A layout in which a set of machines, chosen so that it can carry out the complete processing
of a given family of products, is laid out together in one area.

Jig
A device which holds parts in an exact position and guides the tool that works on them.

Line Analysis
Part of production flow analysis (q.v). A technique used to study the flow of materials
between the machines in a group, in order to find the best arrangement for their layout.

Line Layout
A layout in which the machines are set out in a line in their sequence of use, with materials
flowing along the line.

Plant Layout
The arrangement of the desired machinery and equipment of a plant, established or con-
templated, in the way which will permit the easiest flow of materials, at the lowest cost and with the
minimum of handling, in processing the product from the receipt of raw materials to the dispatch of the
finished product.

Process Layout
A layout in which all machines or processes ofthe same type are grouped together.

Product Layout
A layout in which all machines or processes Concerned in the manufacture of the same
product or range of products are grouped together.

Production Flow Analysis

A technique used to study the flow ofmaterials in a factory and to find the best division into
groups and families for group layout (q.v.). 413
 APPENDIX 1

Tooling Analysis
Part of production flow analysis (q.v.). A technique used to find the sequence for loading
parts on a machine which will give minimum setting time.

Workplace Layout
A convenient term used to describe the space and the arrangement of facilities and conditions
provided for a worker in the performance of a specified job.

C. Management

Budgetary Control
A means of controlling the activities of an enterprise by carefully florecasting the level of each
activity and converting the estimate into monetary terms. The actual cost of or revenue from each
activity is checked against the estimates.

Incentive Scheme
Any system of remuneration in which the amount earned is dependent on the results
obtained, thereby offering the employee an incentive to achieve better results.

lnspection
The application of tests with the aid of measuring appliances to discover whether a given item
or product is within specified limits of variability.

Maintenance (in the management sense)

The systematic inspection, servicing and repair of plant, equipment and buildings with a view
to preventing breakdowns while in use.

Market Research
The gathering, recording and analysing of all facts about problems relating to the transfer
and marketing of specified goods and services from producer to consumer.

Marketing Policy
The policy of an enterprise regarding the marketing of its products or services. It includes
questions relating to the range of goods or services to be offered, markets to be entered, price ranges,
selling methods, distribution and sales promotion, and the appropriate policy mix to be followed by
management with regard to the marketing of its products.
"
Material Control
Procedures and means by which the correct quantity and quality of materials and compo-
nents are made available to meet production plans.

Operator Training
The systematic training or retraining of workers in manual skills with a view to ensuring
sound and uniform working methods.

Personnel Policy
The policy of an enterprise towards its employees. It embraces methods of selection, recruit-
ment, training, remuneration, welfare services, consultation, relations with unions, social security and
all other matters in which the attitude of the employer can alfect the quality of working life and well-
41 4 being of those employed.
 APPENDIX 1

Process Planning
The detailed planning of the processes of manufacture necessary to convert raw material into
finished products before commencing operation. The term originated in the engineering industry.

Process Research

Research into the nature and characteristics of a given production process.

Product Development
The stage, usually between design and large-scale production, during which units of the
product are tested and studied with a view to improving performanceo ease of manuf4cture and market
appeal.

Product Research
ReseSrch into the nature and characteristics of a product or potential product in relation to
the functions ifhas to or may have to perform.

Production Control
The planning, direction and control of the supply of materials and processing activities of an
enterprise.

Production Planning
The planning of the physical means of production. It is concerned with process planning, with
the design of tooling, with the layout of plant and equipment and with the handling of materials and
tools in the workshop. Work study is a major technique in production planning.

Productivity
The ratio of output to input.

Progressing
Systematic control procedures designed to ensure that the programmes and orders issued by
production control are carried out.

Quality Control
The function of management which controls the quality of products. It includes inspection
and other procedures and means (including sampling methods based on statistical principles) of main-
taining the quality ofproducts.

Standard Costing
A system of costing in which standard costs are estimated in advance; the actual costs
incurred are compared with the standards and any variance is analysed for causes.

Standardisation
The development and application of a standard for a particular product or type of component
or range ofproducts or components or a given procedure.

Value Analysis
The systematised investigation of the product and its manufacture to reduce cost and
improve value.

Variety Reduction
The systematic reduction of the number of varieties of products made and materials, parts
and tools used in a factory.

415
 z. Check-list of questions
whichmaybeof use in app$ng
the questioning sequence
in method study
Most of the questions listed below apply generally to method study investigations. They
amplify the questioning procedure described in Chapter 8, and may be of service in suggesting to
studymen aspects of the method which might otherwise be overlooked. The questions are listed under
' the following headings:

A. Operations G. Work Organisation

B. Design H. Workplace Layout
C. Inspection Requirements I. Tools and Equipment
D. Material Handling J. Working Conditions
E. Process Analysis K. Job Enrichment
F. Material

A. Operations
l. What is the purpose of the operation?
2. Is the result obtained by the operation necessary?
If so, what makes it necessary?
3. Is the operation necessary because the previous operation was not performed correctly?
4. Is the operation instituted to correct a condition that has now been corrected otherwise?
5. If the operation is being carried out to improve appearance, does the additional cost give
extra saleability?
6. Can the purpose ofthe operation be obtained in another way?
7. Can the material supplier perform the operation more economically?
8. Is the operation being performed to satisfy the requirements of all users of the product, or is it
made necessary by the requirements of one or two customers only?
9. Does a subsequent operation eliminate the necessity for this operation?
10. Is the operation being performed as a result ofhabit?
I 1. Was the operation established to reduce the cost of a previous operation, or a subsequent
operation?
12. Was the operation added by the sales department as a special feature?
13. Can the part be purchased at a lower cost?
14. Would adding a further operation make other operations easier to perform?
15. Is there another way to perform the operation and still maintain tlre same results?
16. Ifthe operation has been established to correct a subsequent difficulty, is it possible that the
corrective operation is more costly than the dfficulty itself?
17. Have conditions changed since the operation was added to the process?
18. Could the operation be combined with a previous or a subsequent operation? 417
 B. Design
1. Can the design be changed to simplify or eliminate the operation?
2. Is the design ofthe part suitable for good manufacturing practice?
3. Can equivalent results be obtained by changing the design and thus reducing cost?
4. Can a standard part be substituted?
5. Would a change in design mean increased saleability, an increased market?
6. Can a standard part be converted to do thejob?
1. Is it possible to improve the appearance of the article without interfering with its utility?
8. Would an additional cost caused by improved appearance and greater utility be offset by
increased business?

9. Has the article the best possible appearance and utility on the market at the price?
10. Has value analysis been used?

C. Inspection Requirements
l. What are the inspection requirements for this operation?
2. Does everybody involved know exactly what the requirements are?
3. What are the inspection details of the previous and following operations?
4. Will changing the requirements of this operation make it easier to perform?
5. Will changing the requirements of the previous operation make this operation easier?
6. Are tolerance, allowance, finish and other standards really necessary?
7. Can standards be raised to improve quatity without unnecessary cost?
8. Will lowering standards reduce cost considerably?
9. Can the hnished quality of the product be improved in any way above the present standard?
10. How do standards for this operation/product compare with standards for similar items?
11. Can the quality be improved by using new processes?
12. Are the same standards necessary for all customers?
13. Will a change in standards and inspection requirements increase or decrease the defective
work and expense in the operation, shop or field?
14. Are the tolerances used in actual practice the same as those shown on the drawing?
15. Has an agreement been reached by all concerned as to what constitutes acceptable quality?
16. What are the main causes of rejections for this part?
17 . Is the quality standard definitely fixed, or is it a matter of individual judgement?

D. Material Handling
l. Is the time spent in bringing material to the work station and in removing it large in propor-
tion to the time used to handle it at the work station?
2. Ifnot, could material handling be done by the operatives to provide a rest through change of
occupation?
3. Should hand, electric or fork-lift trucks be used?
4. Should special racks, containers or pallets be designed to permit the handling of material with
ease and without damage?
5. Where should incoming and outgoing materials be located in the work area?
4 1 8 6. Is a conveyor justified, and if so, what type would best be suited for the job?
 APPENDIX 2

7. Can the work stations for progressive steps ofthe operation be moved closer together and the
material-handling problem overcome by gravity chutes?
8. Can material be pushed from operative to operative along the bench?
g. Can material be dispatched from a central point by means of a conveyor?
10. Is the size of the container suitable for the amount of material transported?
I l. Can material be brought to a central inspection point by means ofa conveyor?
12. Could the operative inspect his own work?
13. Can a container be designed to make material more accessible?
14. Could a container be placed at the work station without removing the material?
15. Can an electric or air hoist or any other lifting device be used with advantage?
16. If an overhead travelting crane is use4 is the service prompt and accurate?
17. Can a tractor-trailer train be used? Could this or an individual railway replace a conveyor?
18. Can gravity be utilised by starting the ltrst operation at a higher level?
lg. Can chutes be used to catch material and convey it to containers?
20. Would flow process charts assist in solving the flow and handling problem?
21. Is the store effrciently located?
22. Are truck loading and unloading stations located centrally?
23. Can conveyors be used for floor-to-floor transportation?
24. Can waist-high portable material containers be used at the work stations?
25. Can a finished part be easily disposed oP
26. Would a turntable eliminate walking?
27. Can incoming raw material be delivered at the hrst work station to save double handling?
28. Could operations be combined at one work station to save double handling?
29. Would a container of standard size eliminate weighing?
30. Would a hydraulic lift eliminate a crane service?
31. Could the operative deliver parts to the next work station when he disposes of them?
32. Are containers uniform to p€rmit stacking and eliminate excessive use of floor space?
33. Could material be bought in a more convenient size for handling?
34. Would signals, i.e. lights, bells, etc., notifying men that more materid is required, save delay?
35. Would better scheduling eliminate bottlenecks?
36. Would better planning eliminate crane bottlenecks?
37. Can the location ofstores and stockpiles be altered to reduce handling and transportation?

E. Process Analysis
l. Can the operation being analysed be combined with another operation? Can it be eliminated?
2. Can it be broken up and the various parts ofthe operation added to other operations?
3. Can a part of the operation being performed be completed more effectively as a separate
operation?
4. Is the sequence ofoperations the best possible, or would changing the sequence improve the
operation?
5. Could the operation be done in another department to save the cost of handling?
6. Should a concise study of the operation be made by means of a flow process chart? 419
 APPENDIX 2

7. Ifthe operation is changed, what effect will it have on the other operations? On the finished
product?
8. If a different method of producing the part can be used, will it justify all the work and activity
involved?
9. Can the operation and inspection be combined?
10. Is the job inspected at its most critical point, or when it is completed?
I l. Will a patrol form of inspection eliminate waste, scrap and expense?
12. Are there other similar parts which could be made using the same method, tooling and set-
up?

F. Material
l. Is the material being used really suitable for the job?
2. Could a less expensive material be substituted and still do the job?
3. Could a lighter-gauge material be used?
4. Is the material purchased in a condition suitable for use?
5. Could t}te supplier perform additional work on the material that would improve usage and
decrease waste?
6. Is the material suffrciently clean?
7. Is the material bought in amounts and sizes that give the greatest utilisation and limit scrap,
offcuts and short ends?
8. Is the material used to the best possible advantage during cutting, processing?
9. Are materials used in connection with the process-oils, water, acids, paint, gas, compressed
air, electricity-suitable, and is their use controlled and economised?
10. How does the cost of material compare with the cost of labour?
I l. Can the design be changed to eliminate excessive loss and scrap material?
12. Can the number of materials used be reduced by standardisation?
13. Could the part be made from scrap material or offcuts?
14. Can newly developed materials-plastics, hardboard, etc.-be used?
15. Is the supplier of the material performing operations on it which are not necessary for the
process?

16. Can extruded materials be used?

17. If the material was of a more consistent grade, could better control of the process be estab-
lished?
18. Can a fabricated part be substituted instead of a casting to save pattern costs?
19. Is the activity low enough to warrant this?
20. Is the material free from sharp edges and burrs?
21. What effect does storage have on material?
22. Could a more careful inspection of incoming materials decrease diffrculties now being
encountered in the shop?
23. Could sampling inspection combined with supplier rating reduce inspection costs and delays?
24. Could the part be made more economically from offcuts in some other gauge of material?

G. Work Organisation
l. How is the job assigned to the operative?
42O 2. Are things so well controlled that the operative is never without a job to do?
 APPENDIX 2

3. How is the operative given instructions?

4. How is material obtained?
5. How are drawings and tools issued?
6. Is there a control on time? If so, how are the starting and hnishing times of the job checked?
7. Are there many possibilities for delays at the drawing-room, tool-room and store-room and
at the clerk's office?
8. Does the layout ofthe work area prove to be effective, and can it be improved?
9. Is the material properly positioned?
10. If the operation is being performed continually, how much time is wasted at the start and end
of the shift by preliminary operations and cleaning up?
11. How is the amount of finished material counted?
12. Is there a deflrnite check between pieces recorded and pieces paid for?
13. Can automatic counters be used?
14. What clerical work is required from operatives for filling in time cards, material requisitions
and the like?
15. How is defective work handled?
16. How is the issue and servicing oftools organised?
17. Are adequate records kept on the performance ofoperatives?
18. Are new employees properly introduced to their surroundings and do they receive sufficient
instruction?
19. When workers do not reach a standard of performance, are the details investigated?
20. Are suggestions from workers encouraged?
21. Do the workers really understand the incentive plan under which they work?

H. Workplace Layout
l. Does the plant layout aid effrcient material handling?
2. Does the plant layout allow eflicient maintenance?
3. Does the plant layout provide adequate safety?
4. Is the plant layout convenient for setting-up?
5. Does the plant layout help social interaction between the operatives?
6. Are materials conveniently placed at the workplace?
7. Are tools pre-positioned to save mental delay?
8. Are adequate working surfaces provided for subsidiary operations, e.g. inspection and debur-
ring?
9. Are facilities provided for the removal and storage of swarf and scrap?
10. Is adequate provision made for the comfort ofthe operative, e.g. fan, duckboard or chairs?
I l. Is the lighting adequate for thejob?
12. Has provision been made for the storage oftools and gauges?
13. Has provision been made for the storage ofthe operatives' personal belongings?

I. Tools and Equipment

l. Can a jig be designed that can be used for moret}ran one job?
2. Is the volume sufficient to justify highly developed specialised tools and fixtures?
3. Can a magazine feed be used? 421
 APPENDIX 2

4. Could the jig be made of lighter material, or so designed with economy of material to allow
easier handling?
5. Are there other fxtures available that can be adapted to thisjob?
6. Is the design ofthejig correct?
7. Would lower-cost tooling decrease quality?
8. Is the jig designed to allow maximum motion economy?
9. Can the part be quickly inserted and removed from the jig?
10. Would a quick-acting, cam-actuated mechanism be desirable for tightening the jig, clamp or
vice?
I l. Can ejectors be installed on the fxture for automatically removing the part when tJre fxture
is opened?
12. Are all operatives provided with the same tools?
13. Ifaccurate work is necessary, are proper gauges and other measuring instruments provided?
14. Is the wooden equipment in use in good condition and are work benches free from splinters?
15. Would a special bench or desk designed to eliminate stooping, bending and reaching reduce
fatigue?
16. Is pre.setting possible?
17. Can universal tooling be used?
18. Can setting time be reduced?
19. How is material supply replenished?
20. Can a hand or foot air-jet be supplied to the operative and applied with advantage?
21. Could jigs be used?
22. Could guides or bullet-nosed pins be used to position the part?
23. What must be done to complete the operation and put away all the equipment?

J. rilorklng Conditions
l. Is the light even and sufficient at all times?
2. Has glare been eliminated from the workplace?
3. Is the proper temperature for comfort provided at all times; if not, can fans or heaters be
used?
4. Would installation of air-conditioning equipment be justified?
5. Can noise levels be reduced?
6. Can fumesn smoke and dirt be removed by exhaust systems?
7. If consrete floors are usd are duckboards or matting provided to make standing more com-
fortable?
8. Can a chair be provided?
9. Are drinking fountains with cool water provided and are they located nearby?
10. Has due consideration been given to safety factors?
I l. Is the floor safe, smooth but not slippery?
12. Has the operative been taught to work safely?
13. Is the clothing suitable from a safety standpoint?
14. Does the plant present a neat and orderly appearance at all times?
422 15. How thoroughly is the workplace cleaned?
16. Is the plant unduly cold in winter, or stuffy in summer, especially on the first morning of the
week?
17. Are dangerous processes adequately guarded?

K. Job Enrichment
l. Is the job boring or monotonous?
2. Can the operation be made more interesting?
3. Can the operation be combined with previous or subsequent operations to enlarge it?
4. What is the cycle time?
5. Can the operative do his own setting?
6. Can he do his own inspection?
7. Can he deburr his own work?
8. Can he service his own tools?
9. Can he be given a batch of tasks and do his own scheduling?
10. Can he make the complete part?
I l. Isjob rotation possible and desirable?
12. Can group layout be used?
13. Are flexible working hours possible and desirable?
14. Is the operation machine paced?
15. Can buffer stock be provided to allow variations in work pace?
16. Does the operative receive regular information about his performance?

423
- Example
3.
of tab-les used to calculate
relaxation allowances

(United
This appendix is based on information supplied by Peter steele and Partners
Kingdom). similar tables have been developed by variouJinstitutions, such as
REFA (Federal Republic
of Germany), and by other consulting hrms.
strains and
Relaxation allowances may be determined by means of the tables of comparative
The analysis should proceed as follows:
the points conversion table reproducid in this appendix.

imposed under
(l) For the element of work under consideration, determine the severity of the strain
each sub-heading of the table of strains below, by reference to the tables
of comparative strains'
perfor-
(2) Allocate points as indicated and determine the total points for the strains imposed by the
mance of the element of work.
(3) Read offfrom the points conversion table the appropriate relaxation allowance.

Table l.' Points allocated for various strains: summary

Type of strain

Physical strains resultingfrom nature ofwork

1. Average force exerted G8s Gl13 G,149

2. Posture G5 6-1 I t2-16

G4 5-10 1 l-15
3. Vibration
4, Short cycle G3 4-6 7- 10

5. Restrictive clothing G4 5-t2 l3-20

B. Mental strains
L Concentration/anxietY G4 5-10 1 t-16
2. Monotony U2 3-7 8-10
3. Eye strain G,5 6-l r L2-20

4. Noise 0-2 3-7 8-10

C. Physical or mental strains resultingfrom nalure ofworklng conditions

1. Temperature
Low humidity G5 6-1 I t2-t6
Mediurn humidiry G5 6-14 t5-26
High humidity G6 7-t't 18-36 425
 APPENDIX 3

Type of strain Severity

Low Medium High

2. Ventilation 0-3 4-9 lGls

3. Fumes G3 4-8 9-12
4. Dust G3 4-8 9-12
5. Dirt 0'2 3-6 7-10

6. Wet O-2 3-6 7-10

Ivorej All@ate Doints for sch strain independently, inspec,tjve of what has ben allowed for other strains. If any strain ccurs for only a pro'
ponion of the ti;re, allcate a similr proponion of the points:
e.g. High mnqtfation: 16 points. 25 per cent of the time;
Low con@ntration: 4 points, ?5 per ent of the time.
Allcatel6x0.25:4pointsplus4x0.75:3points,whichgivsstotalof4+3=7points.

TABLES OF COMPARATIVE STRAINS

A. Physicat strains resulting from the nature of the work

1. AVERAGE FORCE EXERTED (FACTOR A.1)

Consider the whole of the element or period for which the relaxation allowance is required
and determine the average force exerted.

ExamPle:
Lift and carry a weight of 40 lb. (time 12 seconds) and return empty-handed (time 8 seconds).
In this example, if the relaxation allowance is to apply to the full 20 seconds' the "average
force exerted" should be calculated as follows:

(*,,or). (o,t): zaru.

The number of points allocated for the average force exerted will depend upon the type of
stress involved. Stresses are classified as follows:

(a) Medium stress

(i) Where the work is primarily concerned with carrying or supporting loads;
(ii) shovelling, swinging hammers and other rhythmical movements'
This category covers most operations.
(b) Low stress
(i) Where the weight of the body is transferred in order to exert force, e.g. foot-pedal operation;
pressing an article, with the body, against a buff;
(ii) supporting or carrying well balanced loads strapped to the body or hung from the shoulders;
arms and hands free.
(c) High stress
(i) Where the work is primarily concerned with lifting;
(ii) exerting the force by continued use of certain muscles of fingers and arms;
(iii) lifting or supporting loads in awkward attitudes, manipulation of heavy weights into awkward
positions;
(iv) operations in hot conditions, hot metalworking, etc.
Relaxation allowances should be awarded in this category only after every endeavour has been
426 made to improve facilities which will make the physical task lighter.
 APPENDIX 3

Table ll. Medium stress: points for average force exerted

00000368101214
l0 15 16 t7 l8 t9 20 2t 22 23 24
20 25 26 27 28 29 30 31 32 32 33

30 34 35 36 37 38 39 39 40 41 4r
40 42 43 44 45 46 46 47 48 49 50
50 50 51 51 52 53 54 54 55 s6 56
60 5'.1 58 59 59 60 61 61 62 63 64
70 64 65 65 66 67 68 69 70 70 ',tr
80 72 72 72 73 73 74 74 75 76 '16

90 77 78 79 79 80 80 81 82 82 83
100 84 8s 86 86 87 88 88 88 89 90
110 91 92 93 94 95 95 96 96 97 97
t20 97 98 98 98 99 99 99 100 100 100
130 101 101 102 to2 103 104 105 106 107 108
140 109 109 109 l 10 I 10 III trz tr2 tt2 I 13

Table lll. Low stress: points for average force exerted

000003678910
r0 ll t2 13 t4 t4 15 16 16 t7 18
20 19 19 20 2t 22 22 23 23 24 25

30 26 26 27 27 28 28 29 30 31 3l
40 32 32 33 34 34 35 35 36 36 37
50 38 38 39 39 40 4t 4t 42 42 43
60 43 43 44 44 45 46 46 47 47 48
70 48 49 50 50 50 5l 5l s2 52 53
80 s4 s4 54 55 55 56 56 57 58 58
90 s8 59 s9 60 60 60 6t 62 62 63
100 63 63 64 65 65 66 66 66 67 67
110 68 68 68 69 69 70 7r 7t '.71 72
120 72 ',13 73 73 74 74 75 75 76 76
r30 77 77 77 78 78 78 79 80 80 81
140 81 82 82 82 83 83 84 84 84 85

427
 APPENDIX 3

Table lV. High stress: points for average force exerted

00003681r1315 t7 l8
l0 20 2t 22 24 25 27 28 29 30 32
20 33 34 35 37 38 39 40 4t 43 44
30 45 46 47 48 49 50 51 52 54 55
40 56 57 58 59 60 61 62 63 64 65
s0 66 67 68 69 10 7t 72 73 74 75

60 76 16 77 78 79 80 8l 82 83 84
70 85 86 87 88 88 89 90 9l 92 93
80 94 94 9s 96 97 98 99 100 l0r tol
90 to2 103 104 105 10s 106 107 108 109 ll0
100 110 lll ttz 113 ll4 ll5 115 116 ll7 ll8
ll0 ll9 119 120 t2t 122 t23 t24 t24 t25 126
120 r27 t28 128 129 130 130 131 132 133 r34
r30 135 136 136 r37 t37 138 139 140 t4t 142
r40 142 t43 143 144 145 146 t47 148 148 149

A study should be made of the elements in relation to low, medium and high stress condi-
tions. The points to be allocated, according to the type of stress and tJre average force applied, are set
out in tables II to IV.

Example: If the weight carried is 25 lb.-

(i) determine the type of stress involved (medium, low or high);
(ii) in the left-hand column of the table for the type of stress (table U, II or IV), find the line
for 201b.;
(iii) on this line, move across the table to the right, to column 5;
(iv) read off the points allocation for 25 lb. carried, which is-
table II, medium stress: 30 Points;
table III, low stress: 22 Points;
table IV, hilh stress: 39 Points.

2. POSTURE (FACTOR A.2)

Consider whether the worker is sitting, standing, stooping or in a cramped position and
whether a load is handled easily or awkwardly.

Points
Sitting easily 0
Sitting awkwardly, or mixture of sitting and standing 2
Standing or walking freely 4
Ascending or descending stairs unladen 5

Standing or walking with a load 6

Climbing up or down ladders, or some bending, lifting, stretching or throwing 8
Awkward lifting, shovelling ballast to container l0
Constant bending, lifting, stretching or throwing t2
428 Coalmining with pickaxes, lying in a low seam 16
 APPENDIX 3

3. VIBBATION (FACTOR A.3)

the addition to mental
Consider the impact of the vibration on the body, limbs or hands and
effort due to it, or to a series ofjars or shocks'
Points
I
Shovelling light materials
Power sewing-machine
I 't
Power press or guillotine if operative is holding the material
I
Cross-cut sawing
Shovelling ballast \ 4
Portable power drill operated by one hand I
6
Pickaxing
8
Ppwer drill (two hands)
15
Road drill on concrete

4, SHORT CYCLE (HIGHLY REPETITIVE) (FACTOR A.4I

is continuously
In highly repetitive work, if a series of very short elements form a cycle which
points indicated below, to compensate for the lack ofopportunity
repeated for a lon! period, award as
to vary the muscles used during the work.
Average cYcle time
(centhainutes) Points
I
l6- 17
2
l5
J
13-14
4
12
lGll 5
6
8-9
1
1
8
6
5
9

Less than 5
l0

5. RESTRICTIVE CLOTHING (FACTOR A.5I

movement. Consider also
Consider the weight of the protective clothing in relation to effort and
whether ventilation and breathing are affected.
Points
t
Thin rubber (surgeon's) gloves
Household rubber gloves \ 2
Rubber boots I
3
Grinder's goggles
Industrial rubber or leather gloves
8
Face mask (e.g. for paint-spraying)

Asbestos suit or tarPaulin coat

t5

Restrictive protective clothing and respirator

20 429
 APPENOIX 3

B. Mental strains
CONCENTRATION/ANXIETY (FACTOR 8.1 )
Consider what would happen if the operative relaxed his attention, the responsibility carried,
the need for exact timing of movements, and the accuracy or precision required.

Points
Routine simple assembly
\ 0
Shovelling ballast I
Routine packing, labourer washing vehicles I I
Wheeling trolley down clear gangway I
Feed press tool; hand clear ofpress
1 2
Topping up battery I

Painting walls 3

Assembling small and simple batches, performed without much thinking

\
Sewing-machine work, automatically guided I
Assembling warehouse orders by tro[ey \
Simple inspection I
Loadlunload press tool, hand feed into machine \
Spray-painting metalwork I
Adding up figures
\
Inspecting detailed components /
Buffrng and polishing
Guiding work by hand on sewing-machine
Packing assorted chocolates, memorising pattern and selecting accordingly
l0
Assembly work too complex to become automatic
Welding parrs held in jig
Driving a motor bus in heavy traffic or fog \ t5
Marking out in detail with high accuracy I
2. MONOTONY (FACTOR 8.2)
Consider the degree of mental stimulation and if there is companionship, competitive spirit,
music, etc.

Points
Two men on jobbing work 0
Cleaning own shoes for half an hour on one's own 3

Operative on repetitive work \ 5

Operative working alone on non-repetitive work I
Routine inspection 6

Adding similar columns of figures 8

One operative working alone on highly repetitive work 1l

3. EYE STRAIN (FACTOR B.3I

Consider the lighting conditions, glare, flicker, illumination, colour and closeness of work and
430 for how long the strain is endured.
 APPENDIX 3

Points
Normal factory work 0
Inspection of easily visible faults
Sorting distinctively coloured articles by colour 2
Factory work in poor lighting
Intermittent inspection for detailed faults \ 4
Grading apples I
Reading a newspaper in a motor bus 8

Arc-welding using mask

l0
Continuous visual inspection, e.g. cloth from a loom
Engraving using an eyeglass t4

4. NOrsE (FACTOR B.4)

Consider whether the noise affects concentration, is a steady hum or a background noise, is
regular or occurs unexpectedly, is irritating or soothing. (Noise has been described as "a loud sound
made by somebody else".)

Points

Work in a quiet oflice, no distracting noise \ 0

Light assembly factory t
Work in a city offrce with continual traflic noise outside I

Light machine shop

\ 2
Office or assembly shop where noise is a distraction f
Woodworking machine shop 4

Operating steam hammer in forge 5

Rivetting in a shipyard 9

Road drilling 10

ifJ?iffi n' # :il:i:',f,ff :niil#,=

',3;
1. TEMPERATURE AND HUMIDITY (FACTOR C.II
Consider the general conditions of atmospheric temperature and humidity and classify as
indicated below. Select points according to average temperature within the ranges shown.

Humidity Tmpsrature
(per enO
up to 75oF 760 to qFF Ovs 90F

Up to 75 0 6-9 t2-16
76-85 l-3 8-t2 t5-26
Over 85 4-6 t2-t7 2U36
431
 APPENDIX 3

a
2. VENT]LATION (FACTOR C.2I

Consider the quality and freshness ofthe air and its circulation by air-conditioning or natural
draught.

Poinls

Offices \ 0
Factories with "office-type" conditions J
Workshop with reasonable ventilation but some draught 1

Draughty workshops
Working in sewer t4

3. FUMES (FACTOR C.3}

Consider the nature and concentration of the fumes: whether toxic or injurious to health;
irritating to eyes, nose, throat or skin; disagreeable odour.

Points

Lathe turning with coolants 0

Emulsion paint I
I
91'.'$rinr..
Soldering with resin
i I

Motor vehicle exhaust in small commercial garage 5

Cellulose painting 6

Moulder procuring metal and filling mould l0

DUST (FACTOR C.4I

Consider the volume and nature of the dust.

Oflice I
Normal light assembly operations 0
I
Press shop I
Grinding or buffing operations with good extraction I
Sawing wood 2

Emptying ashes 4

Linishing weld 6

Running coke from hoppers into skips or trucks r0

Unloading cement ll
Demolishing building t2

5. DIRT (FACTOR C.sI

Consider the nature of the work and the general discomfort caused by its dirty nature. This
allowance covers "washing time" where this is paid for (i.e. where operatives are allowed three minutes
432 or five minutes for washing, etc.). Do not allow both points and time.
 APPENDIX 3

Poinls

Offrce work \ 0
Normal assembly operations I
OfTice duplicators I
.,
Dustman
Stripping internal oombustion engine 4

5
Work under old motor vehicle
7
Unloading bags of cement
Coalminer \ l0
Chimney-sweep with brushes I
6. WET (FACTOR C.6)
Consider the cumulative effect of exposure to this condition over a long period.

Points

Normal factory oPerations 0

Outdoor workers, e.g. Postman I

Working continuously in the damP 2

Rubbing down walls with wet pumice block 4

5
Continuous handling of wet articles
Laundry wash-houseo wet work, steamy, floor running with water, hands wet l0

POINTS CONVERSION TABLE

Table v. Percentage relaxation allowance for total points allocated

0l010l0lol0l0l011llll
10 1l 1l ll ll 1l 12 12 12 12 12
20 13 13 13 13 14 14 14 14 15 15

30 15 16 16 16 r7 t7 t7 l8 18 18

40 19 19 20 20 21 21 22 22 23 23
50 24 24 2s 26 26 27 27 28 28 29

60 30 30 31 32 32 33 34 34 35 36
70 37 37 38 39 40 40 4t 42 43 44
80 45 46 47 48 48 49 50 sl s2 53

90 54 ss 56 57 58 59 60 61 62 63
l0o 64 65 66 68 69 70 7t 72 73 74
llo 75 77 78 19 80 82 83 84 8s 87

120 88 89 9l 92 93 95 96 97 99 100
130 101 lo3 lo5 106 lo7 109 I l0 ll2 I 13 I 15
r40 116 118 ll9 l2t 122 123 125 126 t28 130

Example: If the total number of points allocated for the various strains is 37:
(i) in the left-hand column of table v, find the line for 30;
(ii) on this line, move across the table to the right, to column 7;
(iii) read offthe relaxation allowance for 37 points, which is 18 per cent. 433
 EXAMPLES OF CALCULATIO.N OF RELAXATION ALLOWANCES
l. Power press operation. As press guard opens automatically, reach in with left hand, grasp
piece-part, and disengage it. With left hand move piece-part to tote bin, while right hand places new
blank in press tool. Withdraw right hand, while left hand closes guard. Operate press with foot.
Simultaneously, with right hand reach to tote bin, grasp blank and orient it in hand, move blank near
guard and wait for guard to open.
On 20-ton press. Maximum reach 50 cm (20 in.). Posture ssmewhat unnatural; seated at
machine. Noisy department, adequate lighting.
2. Carry 50 lb. sack up stairs. Lift sack on to bench 90 cm (3 ft.) high; transfer to shoulder,
carry up stairs, drop sack on floor. Dusty conditions.
3. Pack chocolates in three layers of 4 lb. box, according to pattern for each layer, average
160 chocolates. Operative sits in front ofstraight shelves bearing I I kinds ofchocolates in trays or tins;
he must pack the chocolates according to a memorised pattern for each layer. Air-conditioned, good
Iight.

Table Vl. Calculation of relaxation allowances: examples

Typ€ of shain

Powr pres Carrying 50 lb. Packing

operation sack chmolates

A. Physical strains
l. Average force (lb.) M50
2. Posture L4M6L2
3. Vibration L2L-
4. Short cycle
5. Restrictive clothing

B. Mental strains
1. Concentration/anxiety M 6LIH 10
2. Monotony M 6LIL )
3. Eye strain L 3-L 2
4. Noise M 4LL I
C. Working conditions
l. Temperature/humidity L/L L/L 3
2. Ventilation _ _ ]
3. Fumes
4. Dust H9
5. Dirt M3L-
6. Wet L-
Total points 38 68 20
Relaxation allowance, including tea breaks (per cent) l8 35 l3

434
4. Conversion factors

(2) To cpnvert column (l)

into olumn (2),
multiply by

Length
Inches Feet 0.083
Inches Centimetres 2.540

Feet Yards 0.333

Feet Metres 0.305

Yards Feet 3.m

Yards Metres 0.914

Poles Yards 5.502

Poles Metres 5.029

Furlongs Miles 0.125

Furlongs Kilometres 0.201

Miles Yards 1,160

Miles Kilometres 1.609

Fathoms Feet 6.mo

Fathoms Metres 1.829

Centimetres Inches 0.393

Metres Feet 3.281

Metres Yards t.094
Metres Poles 0.199
Metres Fathoms 0.546

Kilometres Furlongs 4.975

Kilometres Miles 0.622

Area
Square inches Square feet 0.m69
Square inches Square centimetres 6.452

Square feet Square yards 0.111

Square feet Square metres 0.093

Square yards Square feet 9.000

Square yards Square metres 0.836

Acres Square feet 43.s60

Acres Square miles 0.0016
Acres Square metres 4047.
Acres Hectares 0.405

Square miles Square feet 27,878,4N

Square miles Square kilometres 2.s90 435
 APPENDIX 4

(l) To rcnvert column ( l)

into colum (2),
multiply by

Square miles Hectares 259.2

Square miles Acres 640.
Square centimetres Square inches 0.1 53

Square metres Square feet 10.753.

Square metres Square yards l.196
Square metres Acres 0.0016

Square kilometres Hectares 100.08

Square kilometres Acres 247.tO
Square kilometres Square miles 0.386

Hectares Acres 2.469

Hectares Square kilometres 671.33
Hectares Square miles 0.0038

Volume
Cubic inches Cubic feet 5.787 x l0{
Cubic inches Cubic centimetres 16.39

Cubic feet Cubic yards 0.037

Cubic leet Cubic metres 0.028

Cubic yards Cubic feet 27.000

Cu[ic yards Cubic metres 0.765

Cubic centimetres Cubic feet 3.58 x l0-a

Cubic centimetres Cubic inches 0.061

Cubic metres Cubic yards 1.307

Cubic metres Cubic feet 35.714

Liquid measure
Fluid ounces (Imperial) Fluid ounces (US) 0.914
Fluid ounces (Imperial) Millilitres 28.4r0
Fluid ounces (US) Fluid ounces (Imperial) 1.094
Fluid ounces (US) Millilitres 25.97

Pints (Imperial) Pints (US) 0.833

Pints (Imperial) Quarts 0.500
Pints (Imperial) Gallons (Imperial) 0.125
Pints (Imperial) Litres 0.568

Pints (US) Pints (Imperial) 1.201

Pints (US) Litres 0.473
Gills Pints 0.25
Gills Litres 0.r42
Gallons (Imperial) Gallons (US) 1.201
Gallons (Imperial) Litres 4.546
Gallons (US) Gallons (Imperial) 0.833
Gallons (US) Litres 3.787

Cubic centimetres Litres 1o-2

Litres Pints flmperial) 1.760

Litres Pints (US) 2.tt3

Weight
Grains (avdp.) Grains (troy) 1.003
436 Grams 0.06s
 APPENDIX 4

(2) To convert column (l)

into @lmn (2),
multiply by

Grains (troy) Grains (avdp.) 0.996

Grams 0.0648

Pennyweight (troy) Grains (troy) 24.000

Grams 1.555

Ounces (avdp.) Ounces (troy) 0.91 l5

Pounds 0.0625
Grams 28.35

Ounces (troy) Ounces (avdp.) 1.097

Grams 3 1.103

Pounds (avdp.) Pounds (troy) t.2t5

Ounces (avdp.) 16.0
Kilograms 0.454

Pounds (troy) Pounds (avdp.) 0.823

Ounces (troy) t2.o
Kilograms 0.373

Stones Pounds (avdp.) 14.0

Grams 63s0.297

Tons (short) Pounds (avdp.) 2000.

Kilograms 907.18

Tons (long) Pounds (avdp.) 2240.

Kilograms 1016.

Grams Ounces (avdp.) 0.035

Ounces (troy) 0.032

Kilograms Pounds (avdp.) 2.203

Tons (short) 0.001I
Tons (long) 0.m098

437
5. Selected bibliography

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organrsalfor (Stockholm, Rationalisation Council-Swedish Employers' Confederation-
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Alford, L. P.; Bangs, J .R.: Production handbook(New York, Ronald Press, 2nd ed., 1964).
Allenspach, Heinz:, Flexible working hours (Geneva,ILO' 1975).
Arscott, P. E.; Armstrong, M.: An employer's guide to health and safety management: A handbookfor
indus t ry (London, Engineering Employers' Federation, I 976).
Ashcroft, H.: "The productivity of several machines under the care of one operator", in Journal of the
Royal Statistical Society (London), Series B, Vol. XII, 1950' pp. 145- l5l'
Barnes, Ralph M.: Work sampling (New York and London, John Wiley, 2nd ed.. 1957)'
Motion and time study: Design and measurement of work (NewYork and London.John Wiley'
-: 6th ed., 1969).
Benson, F.: "Further notes on the productivity of machines requiring attention at random intervals",
in Journal of the Royal statistical society, Series B, vol. XIV. 1952. pp. 200.2lO.
Cox, D. R.: "The productivity of machines requiring attention at random intervals", in Journal of
-: the Royal Statistical Society, Series B, Vol. XIII, l95l' pp. 65-82.
Biel-Nisen, H. E.: "Universal maintenance standards",inJournal of Methods-Time Measurement (Fair
Lawn, NJ), Vol. 7, Nos.4 and 5, Nov. l96GFeb. 1961.
Bowman, Edmond; Fetter, Robert Analysis for production management (Homewood, Ill.' Richard
Irwin, l96l).
British Institute of Management: Classiftcation and coding: An introduction and review of classilica-
tion and coding s/stems (London, l97l).
British Standards Institution: Glossary of terms used in work study (London, 1969).
Buffa E. S.: Modern production management (New York and London, John Wiley, 4th ed.' 1973)'
Burbidge, J. L.: Principles of production control(London, Macdonald and Evans, 3rd ed., l97l).
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-; Production
The introduction of group technology (London, Heinemann, 1974).
-:
Bureau des temps 6l6mentaires: Vocabulaire technique concernant l'6tude du travail (Patis, Les Edi-
tions d'organisation, I 954).
"La pr6paration scientifique des d6cisions (recherche op6rationnelle) appliqu6e i l'6tude du tra-
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Carpentier, J.; Cazamian, P.: Night work: Its effects on the health and welfare of the worker (Geneva
ILO, 1977).
Carroll, P.: How to chart dara (New York and London,.McGraw-Hill, 1960).
Carson, G. B. (ed.) et al.: Production handbook (New York, Ronald Press, 3rd ed., 1972).
Cemach, H. P .: Work study in the olfice (Barking, UK, Applied Science Publishers, 4th ed., 1969).
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44"1
 Other ILO publications

Encyclopaedia of occupadonal health and safety

Contains about 9@ alphabetical entries of an essentially practical character relating to various trades, occupa-
tions, processes, machines, substances, affections and so forth. The emphasis throughout is on the hazards for ihe
workers and the safety and health measures to be taken. Numerous photographs, diawings and charts. Analytical
index. In two volumes.
"An indispensable reference work for all those concerned with the protection ofworkers' safety and health, and a
source of practical information, presented objectively and systematically, even for those with no specialised
medical or technical knowledge." (WHO Chronicle, Geneva)
"It should sqtil$ the most learned engineering scientist as well as the youngest safety supervisor." (Carudian
Occlpatlonal Sqfety)
*... a practical, readable tool for large and small enterprises with an active concerr for the workers'well-being."
( S qfety S tandords, Washington)

"... 4n engyclopaedia which should be on the shelves of all health, hygiene and safety departments." (Ocatpa-
tional Health, London)
rsBN 92-2-l0lfrD?

Management consuldng: A guide to the professlon Edited by M. Kubr.

This book is intended for new or future consultants, firms, educational and professional institutes, public and pri-
vate organisations and managers who use consultants.
"This is an excellent handbook for anyone involved in management consulting ... well written and easy to use..."
(B ritis h I nstitute ol Management )
"A valuable contribution to the literature which compared with some professions is still'thin on the ground' ...
comprehensive and informative ... written with an eye to present-day conditions ..l' (The Training Ofricer,Man-
chester)
"Essential for anyone contemplating entry, rerninderful for current practitioners, helpful to users ofconsulting ser-
vices ..." (Cozsultants News, Fitzwilliam, NH)
rsBN 92-2-l0l 165-8

Night work: Its efrects on the health and welfare of the worker. By James Carpentiel and Pierre Cazamian.
"This small book is another of the well compiled reviews by ILO experts.... A wide ranging introduction which
sets the research findings in a historical and industrial contexl The material is commendably up to date. [The
authors'l conclusions regarding the health effectq of night work come down lirmly on the side of clear evidence for
increased ill health.... This is a useful text [and] should interest ugonomists, production engineers and managers
and industrial medical personnel for its coverage of a problem area which is becoming more important every day."
(Applted Ergonom lcs, GuildforQ
ISBN 92-2-101729-X (hard cover); ISBN 92-2-101616-5 (limp cover)

Shift work: Economlc advantages and soclal costs. By Marc Maurice.

". . . The monograph will be a standard reference for the research worker. . . . It has been prepared for the ILO as a
general introduction to questions about shift work. The author summarises the evidence on the extent ofshift work
in different countries. Then he discusses the economic and technological reasons for adopting shift work in a
thorough treatment of the topic, drawing attention to the major economic advantages and disadvantages of shift
work. The consideration of the choice of shift systems and the variety and nature of shift rotas presents in a clear
and simple form the salient features of what can be a complex issue.,,. To conclude, the author writes a
stimulating and imaginative chapter looking to the future." (Ergonomics, London)
ISBN 92-2-101095-3

Job evaluation
Illustrated by concrete examples and information based on actual experience with job evaluation schemes in a
number of countries, this book describes the aims and methods of the system. Problems and criticisms that have
arisen from the use ofjob evaluation as an aid to wage determination are also discussed.
"An important contribution to the wider understanding... ofthe meaning and general principles ofjob
evaluation." ( Co mmerce, Bombay)
rsBN 92-2-10003r-l

New forms of work organisation, Vol. I

This is the first volume in a series consisting of country monographs and more broad-ranging comparative studies.
The case studies included in this book relate to France, the Federal Republic of Germany, the Scandinavian
countries, the United Kingdom and the United States. They are preceded by an introduction explaining the concep
tual framework of the projecr These monographs demonstrate the growing trend towards the adoption of new
forms of work organisation in dilferent contexts, the dilliculties and complexities involved, and the potential for
success. They also show the considerable dilferences among national approaches and experience.
442 ISBN 92-2-l0l99l-8