Work Study
30th October, 2007
What is work Study
Work Study is defined as process which is used
to examine human work in all its contexts.
It leads to systematic investigations of all factors which effect the efficiency of situation being reviewed
To Seek Improvements
It aims at finding the best and efficient way of using : Men , Material, Money & Machinery
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Elements of Work Study
Method and Motion Study:
Systematic investigation of existing method in order to develop and install an easy ,rapid ,efficient , effective and less fatiguing procedure for doing same job at lower costs. Done by eliminating unnecessary motions, alteration of sequence in a process or alteration of process itself
Work Measurement
Application of different techniques to measure and establish the time required to complete the job by a qualified worker at a defined level of performance
Work Study Advantages & Applications
Advantages:
Unfiform and improved production flow Higher productive efficiency Reduced manufacturing costs Fast and accurate delivery dates Better Wage setting procedures
Applications of Work Study:
Industries ( production operations,research and development)
Marketing,sales and distribution
Offices,stores and warehouses, Material handling
Building and constructions
Hospitals and army and agriculture.
Method Study - Procedure
Select and set objectives:
To reduce manufacturing cost Reduce bottle neck
Increase operator efficiency
Record all data pertaining to existing method by:
Process Charts :
1. Flow process chart
2. Two handed process chart 3. Multiple activity chart Flow Diagrams Models Motion and film analysis: 1. Simo chart - Simultaneous Motion Chart
Flow Process Charts for Data Recording
This chart uses This chart is of 3 types: Man Activities of operator machine - Manner in which the equipment is used Material - the changes the material undergoes in location or condition
Process
circles for operations
arrows for transports squares for inspections triangles for storage letter D for delays.
Before Layout Revision
Sl. No . 1 2 3 4 5 6 7 8 9 10 11 12 Operation M achine
Storage Coining Storage + Relief Plug Assy. Ball Pressing Storage Leak Check Storage Poppet assembly Bearing Pressing Storage Thrust washer Assy. Storage
Total
From In trolley Press Trolley Press On the Machine Air Gauge Table Table
After Layout Revision
Sl. No. Operation Machine
Process
1 2 3 4 5
Storage Coining Bearing Pressing Ball Pressing Leak Check& Poppet Assy. Thrust washer Assy.
In trolley Press Press Press Table PokaYoke
1 5 0 0 0
Press Table Poka-Yoke -6 6 0 1 4
Total
Vertical lines connect these symbols in the sequence they are performed.
Two handed Process Charts for Data Recording
Two handed process chart records the activities of left and right hand as related to each other
Use of human body
Process
Left hand Operation Pick up Bolt Hold Hold Hold
LH
The two hands should begin and complete their movements at the same time
The two hands should not be idle at the same time except during periods of rest
RH
Right hand Operation Idle Pick up Nut to left hand assemble
Motions of the arms should be symmetrical,in opposite direction and simultaneous
Continuous curved movements are to preferred to straight line motions involving sudden and sharp,changes in direction Work should be arranged so that eye movements are confined to a comfortable area, without the need for frequent changes of focus
Summary of Saving Activity
Operation Transport Check ing Storage
LH
1 0 0 3
RH
2 1 0 1
Multiple Activity Charts for Data Recording
This chart records simultaneously the activities of all the workers and machine on a common time scale and shows inter- relations between them To detect idle times and to decide no. of workers To balance work team and optimize work distributions between workers
Applications: Plant repair and maintenance Planning team work
Flow Diagram for Data Recording
Flow Diagram depicts the probable
movement of materials in the floor plant. The movement is represented by a line
in the plant drawing.
This chart indicates the movement of men and materials If these movement are reduced it will lead to cost and effort reduction The path of movements can be
better visualized
Measures the distances moved and points out if the work stations are
suitably located
Method Study - Procedure
Examine asking questions
Purpose what is done ? Person Who does it ? Place Where it is done ? Means how is it done ? Sequence When it is done 1. Why is it necessary ,why is it done by that method etc., 2. Determine alternate ways of doing 3. Determine best method of of doing
Operation Analysis
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Method Study - Operation Analysis
Detailed study of different operations involved In doing a work Some of the work elements to be Combined Eliminated Altered in sequence Worker in terms of fatigue Setup in terms of modification of setup, availability of equipments and number of setups Material specification,cost
Operation analysis involves in optimizing the processes with regard to:
Material handling backtracking,distance reduction
Operations Tools and fixtures easy to use Work condition lighting,ventilation Identification of productive and idle motions Elimination of unnecessary and non- productive motions Redesign of the existing operatios by employing minimum number of motions and appropriate sequence
Analysis of motion :
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Method Study - Work place Layout design
Materials and tools to be available in predetermined places closes to the worler To be located in the order of their use Use of gravity , for raw material to reach operator wherever possible Comfortable posture for operator Should be able to operate levers and handles without alteration in body postures Working place classification Actual working area most convenient area to work (1) Normal working area it is within the reach of the operator (2) Maximum Working area - It is accessible with full arms stretch (3) 3 1 2
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Method Study - Procedure
Develop best method which is :
Practical , feasible, safe and economical
Acceptable to design and production and quality control and
sales
Install developed method and examine for
problems
Maintain new method by periodic checks
and verifications
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Work Measurement
Work measurement is the application of techniques designed to establish
The time for a qualified worker to
Carry out a specified job at a defined level of
performance
A qualified worker is one who is: Accepted as having the necessary physical attributes,
Who possesses the required intelligence and education,
Who has acquired the necessary skill and knowledge to carry out the work in hand to Satisfactory standards of safety,quantity and quality
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Work Measurement - Application
The uses of work measurement To compare the efficiency of alternative methods To balance the work of members of teams, in association with Multiple activity chart To determine, in association with man machine multiple activity charts, the number of machines an operative can run
The time standards, once set, may then be used:
For production planning and scheduling Determine plant and Labour requirements
To set standards of machine utilisation and Labour
performance and as a basis for incentive schemes To provide information for Labour-cost control 15
Work Measurement Technique Time Study
Time study is a work measurement technique for recording the times and rates
of working for: The elements of a specified job
Carried out under specified conditions,
Analysing the data so as to obtain the time necessary for carrying out the job at a defined level of performance
Basic time study equipment
A stop watch A study board time study forms camera
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Time Study Procedure
Obtaining and recording all the information available about the job, the operative and the surrounding conditions
Recording a complete description of the method,breaking down the operation into elements
An element is a distinct part of a specified job selected for convenience of observation, measurement and analysis
A work cycle is the sequence of elements which are required to perform a job or yield a unit of production.The sequence may sometimes include occasional elements Measuring with a timing device(usually a stopwatch) and recording the time taken for each element At same time, assessing the effective speed of working(Rating)
Extending the observed times to Basic times
Determining the allowances to be made over and above the basic time for the operation Determining the standard time for the operation
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Time Study Rating & Rating Factor
Rating Rating is the assessment of the workers rate of
working relative to the observers concept of the
rate corresponding to standard performance
How the rating factor is used
Observed Time x Rating = Basic time Standard Rating(100)
Basic time is the time for carrying out an
element of work at standard rating
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Time Study Standard Time
+ CA
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Work Measurement Other Techniques
Predetermined Motion Time System (PMTS):
Does not measure elemnt time All manual tasks are made up of certain basic human movement which are common to all jobs The average time taken to perform a movement is constant (BS 3138 :1969) Basic time can be calculated by summing times of all motions and applying rating factor
Method Time Measurement (MTM):
Time measurement unit ( 1 TMU = 0.0006 min.) Analyses the human movements , depending on types of motion and conditions predetermined time values are given for each motion Basic time can be calculated by summing times of all motions and applying rating factor
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