Maintenance Management

UNIT 13 MAINTENANCE MANAGEMENT

Objectives
Upon completion of this unit, you should be able to:
• relate the importance and objectives of maintenance management
• understand the pattern in which failures and breakdowns take place
• realise existence of different systems of maintenance
• realise the need for letting unplanned emergency maintenance remaining an
‘exception rather than a rule’
• comprehend that the efforts involved in maintenance planning and control are worth
it, even though this calls for greater amount of record keeping, and subsequent
analysis
• realise that formal costing and budgeting would encourage prediction and
preplanning of maintenance activities
• identify the need for some control indices for improving the maintenance service of
an organisation.
Structure
13.1 Introduction to Maintenance Management
13.2 Tero-technology
13.3 Objectives of Maintenance
13.4 Failure Analysis
13.5 Types of Maintenance Systems
13.6 Maintenance Planning and Control: Preparation
13.7 Maintenance Planning and Control: Operation
13.8 Maintenance Planning and Control: Progression
13.9 Maintenance Costing and Budgeting
13.10 Maintenance Performance Indices
13.11 Summary
13.12 Key Words
13.13 Self-assessment Exercises
13.14 Further Readings

13.1 INTRODUCTION TO MAINTENANCE

MANAGEMENT
Since time immemorial when man used primitive tools and machines to carry his loads,
to draw his water, to till his land and to fabricate his building materials, he has been
faced with the prospect of maintaining these assets until such time as he considered their
useful life to be ended. Maintenance is very important to extend the useful life of an
asset. It is quite a challenge. In our country, there is no dearth of manpower but rather
scarce limited capital to spend for capital equipment. Some studies have shown
equipment utilisation to be as low as 30% in quite a few cases. Proper maintenance
management could improve existing capacity utilisation rather than going in for
additional capacities to meet the ever increasing demand of a large number of products
and or services. In industry maintenance function is usually given a low status and
considered to be a third rate job; this is rather unfortunate. The function of carrying out
maintenance is such an obvious necessity that the subject has been taken for granted
over the centuries without much thought being given to its importance in our everyday
lives.

Maintenance is usually viewed only as a repair function. It is, however, "a combination
of any actions carried out to retain an item in, or restore it to, an acceptance condition".
In fact maintenance keeps or ensures that the entire production system is kept reliable,
productive and efficient. All departments of a
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production system may have been designed beautifully without giving due consideration
to maintenance management. The end result is obvious. Organisations like the National
Productivity Council and others are playing a vital role in propagating the importance of
Maintenance Management of all the assets of the organisation. In fact, all organisations
must be having some assets, and hence the need for proper maintenance and `physical
assets management' which is synonymous with the word `Tern-technology' which we
shall discuss now.

13.2 TERO-TECHNOLOGY
The concept of tero-technology grew from the study of maintenance practices. It is
synonymous with total maintenance. It takes into account all aspects of plant machinery
from Design to Discard, viz. design, manufacture, installation, commissioning,
maintenance, replacement and removal of the plant/equipment plus the. feedback of
performance for the equipment manufacturer. Tero-technology envisages application of
a combination of managerial, financial, engineering and other practices applied to
physical assets in pursuit of economic life-cycle costs. It is concerned with the
specification and design for reliability and maintainability of plant, machinery,
equipment, buildings and structures. This total life-cycle concept enables a proper
equipment evaluation and selection so as to give an overall low life cycle concept. This
gives rise to huge potential for savings in terms of cost effectiveness of replacements on
considerations of the whole life-cycle. `Design audit' consists of carrying out critical
scrutiny of the designs by the operating and maintenance engineers independent of the
design process so as to ensure reliability and maintainability of plant and machinery and
to identify weaknesses in designs requiring modifications. The word `tero-technology',
itself stems from the Greek root `terein'-`to look after', `to guard over', `to take care of.
In fact the principles of tero-technology as discussed above can be applied, to a greater
or lesser extent, to any physical asset in any organisation, no matter what the size or
degree of complexity of either asset or organisation.

13.3 OBJECTIVES OF MAINTENANCE

Very loosely, some define maintenance as any work undertaken by a maintenance
worker. In manufacturing organisations, the term `works engineering' has been
commonly used to embrace installation, commissioning, maintenance, replacement and
removal of plant, machinery etc. However, when considering service organisations,
municipalities and the armed services, the term is seldom encountered. Fortunately, the
term `tero-technology' covers all these situations, though it would take yet some time for
an universal acceptance of a term like `tero-technology manager'. However, the manager
of the maintenance function whether the job title is estates manager, works manager,
chief engineer, plant engineer, building manager, maintenance manager-is attracting
greater attention then ever before.
The principal objectives of maintenance activity are as follows:
a) To maximise the availability and reliability of all assets, especially plant
equipment and machinery, and obtain the maximum possible return on
investment.
b) To extend the useful life of assets by minimising wear and tear and
deterioration. This is particularly relevant for our country as opposed to
developed countries which would find replacement more economical than
maintenance.
c) To ensure operational readiness of all equipment required for emergency use at
all times, such as standby units, fire fighting and rescue unit etc.
d) To ensure the safety of personnel using facilities
From the line managers' point of view, the reasons for improving maintenance
methods include: (i)protecting the buildings and plant, (ii)increased utilisation
and reducing downtime, (iii) economising in the maintenance depot :dent, (iv)
maximising utilisation of resources, (v) maintaining a safe installation, (vi)
preventing wastage of tools, spares and materials, (vii) providing cost records
for future budgeting.
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Moreover, each day we are witnessing a trend towards increased mechanization
computerisation and greater automation, though it might seem to be a distant thought in
Indian conditions. Whatever be the level or degree of automation, there will always be
an increasing responsibility for the maintainer of the assets. Some of the reasons for this
are:
1) Plant output capacities are raised, making downtime (viz. when the plant is out
of operation) more costly.
2) Dependence on control systems can produce total disruption of output when one
machine or some element in a process fails.
3) The possibilities for operator's intervention to compensate for machine errors or
failures are decreased.
The effects upon the maintenance department include a new requirement for new skills
in repair of computer controls, the need for an improved multi-disciplinary working
coupled with the requirement for a systems approach to maintenance. By systematic
maintenance, it is possible to achieve substantial savings in money, material and
manpower, as every effort is directed towards avoiding catastrophic failure. Failure or
plant breakdown could create problems such as a loss in production time, rescheduling
of production, spoilt materials because of sudden stoppage of process, which could
possibly damage components, failure to recover overheads because of loss in production
hours, need for overtime, need for subcontracting work aid temporary work shortages
etc.

13.4 FAILURE ANALYSIS

Let us now spend some time in understanding how failures take place. Failure analysis
plays a vital role in taking decisions pertaining to maintenance planning and control for
effective management subject to the budgetary constraining for such an activity. It is
important to identify the nature and occurrence of failures with respect to time. This will
be highly significant in designing and ensuring adequate reliable performance. It is seen
that the failure rates pattern can be depicted as a bath tub curve as shown in Figure I.

It is the usual experience with equipments that the failure rate is quite high when the
equipment is new or newly installed. The failure rate is greater during the initial starting
period of infancy but after this initial phase is over, the failures are relatively quite low.
Such behaviour can be approximated to a `hyper exponential distribution' as shown in
Figure I. Such behaviour is a sign of the design defects or installation defects. Therefore,
those that had these inherent defects failed when the equipments were run. Those that
failed much later were those that did not have the design or installation defects. This is
somewhat similar to the infant mortality in humans. 79
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At the other extreme, many equipments fail due to `ageing' and wear out. The failure or
death may be at a 'mean' or `average' age, though some could fail earlier and some later.
Such a failure pattern because of wearing out could be represented by a symmetrical bell
shaped normal distribution.

We have seen the ‘infancy’ and the ‘old age’ phenomenon. In between these two
extremes also equipments may fail, but it is neither due to inherent design or installation
defects nor due to being worn out. The cause is external to the equipment and therefore
probability of failing is constant and independent of the running time. This phenomenon
can be approximated to a `negative exponential' distribution. This is again similar to the
behaviour in humans, where they may die due to external causes such as an epidemic or
traffic-accidents while they are neither old nor infants.

The three distributions mentioned above. namely hyper-exponential, negative

exponential and normal, can be combined into one distribution, termed as the 'weibull'
distribution (named after Weibull who developed it). Hence the bath tub curve depicting
the failure rate can be represented by a weibull distribution. Weibull distribution
calculations are very lengthy and tedious. Fortunately weibull graphs are available
(though not very common) for determining mean time between failure (MTBF). This
would provide good data for determining system reliabilities, availabilities, expected
lives etc. Failure statistics can also be used in the diagnosis of the nature of a recurrent
equipment failure and also in the prescription of solutions to maintenance problems.
The prime objective of maintenance is to increase the availability and reliability of a
piece of equipment. The availability (A) of a plant can be defined as
Tup
A=
Tup +Tdown
where Tup = the cumulative time of operation in the normal working state and Tdown =the
cumulative downtime.

13.5 TYPES OF MAINTENANCE SYSTEMS

Maintenance work can be either planned or unplanned. Let us now discuss the different
types of maintenance systems.
Emergency Maintenance: An unplanned maintenance which is necessary to put in
hand immediately to avoid serious consequences, for instance loss of production,
extensive damage to assets or for safety reasons. Emergencies should remain exceptions
rather than the rule. To ensure such a possibility, it is better to have planned maintenance
systems.
Planned Maintenance: Maintenance organised and carried out with forethought, control
and records to a predetermined plan. Planned maintenance can be split up into
essentially two main activities namely preventive and corrective.
Preventive Maintenance: Also termed `Diagnostic or Predictive Maintenance' is
maintenance carried out at pre determined intervals, or to other prescribed criteria and is
intended to reduce the likelihood of an equipment's condition falling below a required
level of acceptability. You try to anticipate failure and then attempt to prevent its
occurrence by taking preventive actions. The proverbial saying `prevention is better than
cure' or `A stitch in time saves nine' is the basic philosophy of Preventive Maintenance.
Preventive maintenance can be done on machines either when running or during
shutdown.
Running Maintenance: Maintenance which can be carried out when the item is in
service.
Shutdown Maintenance: Maintenance which can only be carried out when the item is
out of service. Further preventive maintenance can be time-based or condition-based.
A Time-based Preventive Maintenance: This policy is effective when the failure of
any item of an equipment is time dependent (in the third stage of the bath tub failure
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curve of Figure l) and the item is expected to wear out within the life of the equipment.
Moreover the total costs of replacement of the item should be substantially less than
those of failure replacement repair,
Condition-based Maintenance is carried out in response. to a significant deterioration
in unit as indicated by a change in a monitored parameter of the unit condition or
performance. It is here that one can make use of predictive maintenance by using a
technique called SIGNATURE ANALYSIS which is intended to continually monitor the
health of the equipment by recording systematically signals or information derived from
the form of mechanical vibrations, noise signals, acoustic and thermal emissions,
changes in chemical compositions, smell, pressure, relative displacement and so on.
Scientific collection of these informative signals or signatures, diagnosis and detection
of the faults, if any, present by a thorough analysis of these signatures based on the
knowledge hitherto acquired in the field, and judging the severity of the faults for
decision-making, all put together, is called `Signature Analysis'. The technique involves
the use of electronic instrumentation specially designed for the purpose of varied
capacities, modes of application and design features. Vibration and noise signals are the
most versatile parameters in machine condition monitoring techniques. Periodic
vibration checks reveal whether troubles are present or impending. Vibration signature
analysis reveals which part of the machine is defective and why. Sound or noise analysis
is somewhat similar to vibration analysis. A stock pulse meter is used to monitor the
condition of roller bearings.
Condition-based maintenance thus reduces injuries and fatal accidents caused by
machinery as the conditions of machinery are indicated well before hand. It enables the
plant to be stopped safely when instant shutdown is not permissible. Moreover, it
permits advanced planning to reduce the effect of impending breakdowns and be in time
to have necessary spare parts available. However, condition monitoring is not always
used because it involves high manpower and monitoring costs and, furthermore, it is
difficult to monitor some parameters.
Corrective Maintenance: Maintenance carried out to restore an item which has ceased
to meet an acceptable condition. It involves minor repairs, that may crop up between
inspections.
Design-out Maintenance is yet another policy which is practised frequently in
developed countries. This is discussed in greater detail later on in this unit. The policy
here aims at minimising the effect of failure and at eliminating the cause of maintenance.
In essence, an attempt is made to pinpoint the defects in the design of the equipment.
Poor design of many an equipment leads to frequent breakdowns. Also an appropriate
choice of tribological materials might eliminate the need for subsequent lubrication
frequencies.

13.6 MAINTENANCE PLANNING AND CONTROL:

PREPARATION
Total maintenance planning embraces all activities necessary to plan, control and record
all work done in connection with keeping an installation to the acceptable standard by
devising appropriate maintenance systems. In a fully controlled situation, the time spent
on emergency work, viz. the `unplanned' portion, could well be less than ten per cent of
the available man-hours in the maintenance department. The administrative control of
maintenance work is very significantly altered when changing from emergency
maintenance methods to a policy of planned maintenance, This brings in some increased
amount of paperwork,
Maintenance Request
The most important single document in the organisation of maintenance we shall
henceforth call the `maintenance request' which is alternatively termed as work order,
work requisition, job card or work ticket etc. As a prerequisite for planning the
'maintenance function, it is necessary to know exactly what the labour force is doing,
and how long each task takes.
The maintenance request by the production staff details the defect or work believed to be
required. Hopefully, the `cause' should have been identified `before' or ‘after’ 81
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rectifying the fault so as to help planners for conducting subsequently studies for critical
analysis and the all important function of `designing-out' maintenance (provided reliable
documented information exists). The maintenance request provides all the information
necessary as regards the type of labour employed, and the time labour has taken to do
the job(Timesheets are often oriented/biased towards the worker).

Assets/Facility Register

The first step of a planned maintenance procedure is to establish what is to be

maintained. This requires the need to establish an Assets/Facility Register. Each asset
must be identified in terms of name and code; description; reference numbers pertaining
to manufacturers, suppliers (if any), users, location with provision for changes if item is
interchangeable or mobile and suppliers' details. When the items are recorded either in a
register or in a card-index form, they could be classified and sub-divided in terms of
asset usage/availability, technical groups or maintenance methods. Sometimes certain
items may be subject to statutory inspections. The assets-register is the information
centre of the planned maintenance system.

Maintenance Schedules

Next we must decide how these assets or facilities are to be maintained. A `maintenance
schedule' must be prepared for every item listed in the assets/facility register. A typical
maintenance schedule card indicates grade of labour required, frequency of the work to
be done, details of the work to be done and estimated time for the execution of the work.
A mistake so often made is when companies setting up a planned maintenance scheme
for the first time prepare the maintenance schedules for all the plant first, and then
endeavour to apply these to a maintenance programme on a specific starting date. In the
absence of plant-history records, this method of approach is doomed to failure, since. it
is just not possible to switch from emergency maintenance methods (which is usually the
rule rather than an exception) to planned preventive maintenance overnight.

Work/Job Specifications

Having prepared our maintenance schedules we must prepare the work/job specifications
which are compiled from the maintenance schedules and are a means of communication
between the engineer and the tradesman (or the person who would be carrying out the
job). Precise specifications for the activities on the maintenance schedule vary in depth
and presentation according to the system, the local labour requirements, the complexity
of the items to be maintained etc.

It should define specific items on the machine requiring attention and clearly indicate the
required action e.g. inspect, check, gauge. It should give guidance in respect of method,
however appropriate it might be. The objective is to maintain to a required standard
without forgetting on the safety aspect concerning both the tradesman and operators.

Programming Annual and Weekly Planned Maintenance Programmes

Having prepared our maintenance schedules and built up a workload from our job
specifications, we are now in a position to commence the preparation of an annual
maintenance programme to decide when the planned productive maintenance jobs shall
be carried out. Over a period of time, planned maintenance significantly reduces the
demands on the maintenance department for such major overhead work to be carried out
during annual shutdown periods (for which we could make use of Network Techniques
like PERT/CPM). The weekly planning maintenance programme can be derived from
the annual planned maintenance programme. However, tactical planning is required at
the weekly level by interacting with the production planning and control section
especially. Unforeseen circumstances sometimes arise, however careful the forward
planning, which make it impossible to release a machine/asset according to the weekly
programme charted out. It is important to communicate the weekly planning
pm1•ramrne, at least -a week ahead, to all concerned.
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Inspection Report
One of the important forms of maintenance is to carry out inspection at the right time
and duly record the data so as to produce an inspection report. This form/document is
used only for reporting the results of planned productive maintenance inspections, as set
out in the job/work specifications. The inspection report closely resembles the
maintenance request, discussed earlier on. It is imperative that inspection reports must be
used by and for maintenance supervision and planned maintenance controller and his
staff prior to filling the history records (to be discussed next).
History Records
The last operation in our planned maintenance procedure is to build up a detailed
historical record of the results of maintenance on every machine receiving it. Plant
history records should be properly updated so that they can be referred to and made use
of more meaningfully. Traditionally, history records have been `written up' by records
clerks from timesheets or work orders.
The operation of an effective maintenance records system provides information about:
(i) the percentage of planned work achieved in the period, (ii) ratio of planned to
unplanned work, (iii) downtime for the period, (iv) maintenance requirement
comparisons between individual assets, between types of asset, or between groups of
assets, (v) indicators for reliability of the products of particular manufacturers, (vi)
trends in spare-parts consumption, (vii) equipment failure patterns,
(viii) performance details for personnel, by individual or by trade group.
Records are kept in many different ways ranging from card files to computerised
devices.
Planned Lubrication
Some form of lubrication routine is rightly considered to be an essential part of plant
maintenance by most firms, yet this is a responsibility which is frequently relegated to
an oiler greaser who may have little or no training before being provided with an oil can,
a grease gun and a dubious supply of lubricants. Lubrication schedules are usually
provided by. the planning engineers of oil companies. The schedules include information
about the number of application points, frequency of each application, method to be
used, e.g. grease gun, oil can etc., the amount and type of lubricant required. Planned
lubrication should be an integral part of planned maintenance, and, because of its utmost
importance, daily and weekly lubrication tasks should usually be carried out separately
from the mechanical and electrical schedules. Monthly lubrication tasks and oil changing
should be usually fully integrated with the maintenance schedules.
To ensure a smooth implementation of planned lubrication techniques, you could adopt a
3-phase procedure. In the first phase, a survey of all plant that require lubrication is
carried out to establish WHAT has to be lubricated. The second phase establishes
WHEN lubrication has to be done and the third phase is to conduct the OPERATION by
establishing HOW lubrication is to be carried out.
Work Priority
Most of us, at some time to a greater or lesser degree, come up against the problems of
deciding job priority. Obviously maintenance work of an emergency nature, required to
keep production going or to reduce downtime, once incurred, should be given the first or
topmost priority. However, with planned maintenance, hopefully, emergency cases are
reduced to just about 10% of all cases. But still some method of priority fixing must be
established preferably. After `emergency', a `machine running' priority could be thought
of. In this case the machine is running, but attention is required to maintain efficient
operation or for safety reasons. Yet the least priority could be labelled `not applicable' if
the request for maintenance work is not relevant w a machine stoppage, and also for
most work involving civil and building trades. 1t.is usually found that these three
priority levels are found to be adequate and acceptable In most instances. If however, me
problem persists. it becomes necessary to devise a PRIORITY. INDEX based on two
important group factors, namely.
a) Work priority factors where all work done by maintenance department personnel 83
Operations Planning and Control
:is separated into 10 classes, most important being class 10 and the least important being
class 1. Emergency Maintenance-I, II and III, Modification, Capital, Sundry aid Special
Maintenance, and housekeeping are respectively ranked from 10 down to 1

b) Facility priority factor in which each facility, plant, building etc. is placed in one of
10 classes, most important being class 1. Key services, key production plant, flowline or
process plant, multi-production machines, standby services, mobile transport, buildings
and roads, machines (low utilisation). building, roads, offices and furniture fittings are
respectively ranked from 10 down to 1.

To obtain the PRIORITY INDEX for any job, multiply `work priority' class by the
'facility/ machine priority' class. You can note that 10 classes have been chosen so that
the priority index for each job can be expressed as a percentage priority.

For example, emergency maintenance for a key service sub-station equipment, the
priority index would be (10x 10) = 100%. For an emergency repair to a leaking roof
(building) over a production machine, the priority index would be (10x4) = 40%.
Safety
Tile observance of safety at work is essential at all times. The general rule is always
‘safety first’. Some of the main safety considerations when carrying out a maintenance
management task are the following:
a) Guards are supplied by plant manufacturers or subsequently fitted by the company.
Safety steps should be taken to ensure that these are not tampered with resulting in
potential hazards. In fact, condition and security of easily accessible guards must always
be included in job specification as items for regular checks at planned preventive-
maintenance inspections.
b) Protective Clothing such as helmets, gloves, goggles, gas masks etc. must be given
full consideration especially in chemical and allied industries. You must preferably
include the need for wearing protective clothing in the maintenance request or the work/
job specification.
c) Power isolation by the use of appropriate fuses might be necessary while
effecting certain types of maintenance tasks. Water and compressed air supplies can
usually be isolated and locked off where necessary. Gas lines may have to be purged
before any welding is permitted.
d) Pressure vessels, piped power, lifting appliance should have some type of a
'permit' system to open and/or blank off.
e) Permit to work for carrying out maintenance tasks should remain valid for a
specific appropriate period only. A copy of the certificate should be posted or affixed in
such a place that it is not possible for anyone to start up the plant or machine before
referring to it.

13.7 MAINTENANCE PLANNING AND CONTROL:

OPERATION
So far we have dealt with the aspects of management organisation that are related to the
needs of the engineering function. Now let us come to the decision-making aspect. If
management is to be truly effective and objective, it must be provided with reliable,
timely, and appropriate information. This aspect is highly desirable. Unfortunately, this
facility is very sadly lacking in the field of maintenance management.

Routine Analysis-Labour and Costs

Let its now discuss some of the problems that arise in the implementation of the system
designed in the earlier section. It is essential to set up operational procedures for routine
analysis of the results of maintenance work in order to improve the level of work
planning and control through bettor control of resources in the form of labour and
materials. Plant and machinery may be wearing out or be obsolete, hind inherent design
faults, uptill now accepted, will be highlighted by the routine analysis. The analysis
might reveal the changes in plant performance as a result of
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planned productive maintenance. Many different types of analysis could be carried out,
but it is good to remember that a successful operation scheme is one that retains
simplicity and some amount of flexibility.
You could conduct a weekly analysis by scanning all completed maintenance requests,
subsequent inspection reports and the total repair time and downtime costs calculated.
The weekly analysis of direct maintenance labour is in hours number of jobs, and
indicates:
i) Maintenance hours activity and maintenance request jobs by cost centre, types of
work and trade group.
ii) Inspection reports by cost centre and trade group.
iii) Total inspection report hours by trade group.
iv) Total downtime' by trade group.
v) Booked time by cost centre.
vi) Total booked time, unbooked time and clocked time by trade group.
vii) Unbooked time as a percentage of clocked time.
viii) Overtime hours worked and expressed as a percentage of clocked time.
ix) Number and total wages of maintenance personnel employ Ld by trade group.
The planned maintenance controller watches closely for any significant variations in
inspection hours achieved, emergency maintenance hours incurred, downtime hours
incurred, unbooked hours recorded and overtime hours worked and as a percentage of
clocked hours.

It is difficult to obtain really accurate maintenance labour costs because these depend on
so many diverse and variable factors, such as time booking accuracy, overtime,
tradesman/unskilled labour ratios, dependent labour charges., workshop overheads,
general overheads etc.
One simple approach is suggested as follows. Every four weeks, total wages paid, plus
dependent labour charges, plus overhead charges are divided by the total clocked hours
for the period; the resultant maintenance labour hour cost rate is directly applied to the
time booked to each cost centre, and each plant number or job number during the period.
It is important to impress upon maintenance workers that they should book only the time
they actually spend on a job (including travelling time, collecting tools and stores for the
specific job only). Some waiting time could be unavoidable in maintenance jobs. It may
be happening that unbooked or overbooked time could arise because of insufficient work
to occupy a maintenance man full] time; careless or inaccurate time booking on the
maintenance request or inspection report; loss of a maintenance request or inspection
report; absence from shop floor Awhile attending training courses which may not have
been recorded by the foreman/superintendent. It might also be helpful to prepare a
weekly summary of all emergency maintenance jobs done during the period.
A plant group analysis could also be done. Machines are deliberateily placed in groups
and types of sub-groups to facilitate identification and enablle the analysis of results to
establish trends of breakdowns and where maintenance performance during the pre-
period was unsatisfactory. By scrutinising the results of maintenance by plant/job
number, it becomes a simple matter to select say the `top ten' machines that have
involved the largest amount of emergency and corrective maintenance and downtime
during the period. It would be worth recording chronologically the `top ten' and see
which machines keep appearing in the list. For such `critical' machines drastic and long
term action may be called for to `design out' the maintenance problems. It should be
anticipated that the top ten analysis might reveal no significant pattern after say 2 years
or so. This will leave the weekly analysis and the plant group analysis as the only two
routines that will continue to be required.
Work Measurement, Manning and Workloading
Most engineering managers would agree that work planning in maintenance is both
possible and desirable. However when it comes to setting certain standards or norms
through work measurement for the largely non-repetitive nature of maintenance work,
one encounters very divergent and strongly held views on the subject'. Incentives might
motivate the maintenance workers to carry out their tasks 85
Operations Planning and Control
effectively and efficiently. Different organisations have different remuneration schemes
for direct production workers and indirect maintenance staff.
Certain aspects ought to be borne in mind when applying work. study techniques to
maintenance engineering. It is a wasted effort to put a standard on a job that can be
eliminated through `design out' maintenance. It is futile to standardise a planned
preventive maintenance job if the worker does not have the correct tools, spare parts or
materials. It is normally impractical or excessively costly to cover more than about 60%
of the jobs. Installation and administration costs are high and can exceed the resultant
benefit. Increased labour productivity remains largely a problem of reducing lost time
between maintenance jobs, i. e. unbooked time.
Work measurement applied to maintenance may have advantages if applied in the right
environment, but maintenance planning and control techniques must be applied first.
Perhaps work sampling schemes could be employed to arrive at the total work content.
Then accordingly appropriate manning levels could be estimated. An organisation that
has a clear cut maintenance planning system would hopefully have a very small
percentage of emergencies occurring. In such well established planned productive
maintenance situations, manning and workloading are not problematic. In fact, in case of
planned overhauls you could resort to the use of network techniques of PERT/CPM
which you have learnt in unit 12.
13.8 MAINTENANCE PLANNING AND CONTROL:
PROGRESSION
Critical Analysis: As maintenance records are being built up and sufficient statistical
data become available, a point is reached when you can attempt to carry out some type
of a CRITICAL ANALYSIS. It would be seen that the Pareto Principle comes in handy
once again, viz. the principle of `the significant few and trivial many.' A critical
breakdown analysis' (Figure Ha) reveals that a small percentage (about 10(;o) of
equipment would significantly contribute to about 70% of the breakdown time. Such
category of equipment could be the so called 'critical `A' type. A defect analysis (Figure
ll b) could also be done. It would be seen here again that a few, say 10% defects
contribute to about 70% of the breakdown times.

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One then needs to concentrate on the critical A types of equipments and the critical A*
types of defects and accordingly devise suitable preventive maintenance management
schemes and design out maintenance, whenever feasible. A simple way for attacking a
maintenance problem is essentially a 3 step procedure.
Step 1: Can it be eliminated? If yes, then no problem. If no, go to next step.
Step 2: Can it be simplified? If yes, then no problem. Otherwise, go to next step.
Step 3: Can it be improved? If yes, then no problem. Otherwise you have hardly
any other option.
Lubrication problem-Costly and time-consuming maintenance operations of greasing the
suspensions, steering and transmission components on a modern motor car, which used
to number a dozen grease points or more, has now been eliminated by design on most
models.
For machines requiring a constant supply of grease to moving parts through a multitude
of often inaccessible individual grease nipples have been through the 3 step procedure,
replaced by the piping of such points in groups of battery plates and thereby reducing the
number of locations at which grease must be applied. Step 2 involved the piping up of
all grease points to an automatic lubricator thereby simplifying maintenance and also
improving quality of service. Where it proves technically impossible to design out
lubrication completely or to simplify it by automatic methods, one may be confronted
with grease and oil sealing problems; these can be improved by better designs of housing
and sealing methods. The penny saved on capital expenditure can be pound foolish when
it has to be spent ON MAINTENANCE.
13.9 MAINTENANCE COSTING AND BUDGETING
Costing and budgeting for the maintenance department embraces the provision of
financial information on labour and materials expenditure, its allocation to the various
cost centres together with manpower resources and the development of objectives with
programmes and budgets for meeting them. The basis for cost control is provided by the
use of cost account codes. Typical major code headings might include (a) capital
projects, (b) planned preventive maintenance, (c) workshop services. The costs
attributable to the cost codes consist broadly of wages and salaries, overhead charges,
materials costs, transport costs and sundry items
The overhead charge made upon maintenance is made up of charges occurring within
the maintenance department plus the overhead charges reflected from other departments
like administration, general management etc. Charges arising within the department
include services' rent and rates, transportation and insurance.
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A budget could then be charted on the basis of the different types of costs estimated for
different heads. A budget might show
Maintenance labour 20
Maintenance materials 40
Fuel costs 25
Overheads 15
When producing a departmental business plan, it is necessary to include in the budget a
set of objectives and strategies for implementing the planned maintenance programmes,
completion of certain capital works and the operation of a planned overhaul programme.
One objective for the department ought to be the reduction of resources allocated to
corrective and emergency maintenance and an increase in planned preventive work.
Cost reports can be analysed for variances of actuals versus planned. In this connection
it is relevant to introduce a `life-cycle cost' concept of an asset. It includes the initial
costs (the total costs of procurement and setting to work), the costs of ownership during
the life-cycle, and the costs of downtime. Initial costs include the costs of services,
commissioning, product support and ancillary equipment. The cost of ownership include
the annual costs of operation and maintenance, multiplied and factored for the life term,
together with salvage value (when asset is disposed). The costs from downtime includes
loss of use, repair costs and consequential damage, and will provide evidence for
replacement decisions. One needs to suitably account for inflationary trends, if they
exist.
Once fully understood, formal costing and budgeting would be extremely useful not only
in predicting and controlling expenditure but in encouraging the prediction and
preplanning of activity with the necessary resourcing to meet
13.10 MAINTENANCE PERFORMANCE INDICES
Unlike direct production which can be rated in terms of output of any particular
machine, no such analytical yardstick is available for rating maintenance. In
maintenance you should essentially strive to maximise availability and reliability of the
machines/ assets and minimise downtime. Maintenance though a support function, is
certainly linked to increase in the productivity of the system in the long run. Chandra has
proposed some indices as below, which might help management achieve their objectives
more effectively and efficiently.

Overtime hours worked is indicative of the failure of planning. Emergencies should be

reduced to a bare minimum.

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13.11 SUMMARY
In several cases in industry, cost of unscheduled stoppage on an equipment is very high
in terms of money and any breakdown or accident could cost a good deal in terms of
money and human injury. Maintenance has not only to reduce scheduled stoppage time
but attempt to avoid unscheduled stoppages and breakdowns by frequent performance
checking, testing and providing inspection and skilful repair when required to ensure
better service, availability and reliability. There are various types of maintenance
management schemes. It is imperative that you use the appropriate technique by
evaluating the cost-benefits of each alternative. There is a need for an effective spare
parts inventory management policy and an overall necessity of adopting a systems
approach. The effectiveness of production is highly dependent on the quality of
maintenance service facility. Perhaps good care, caution and foresight at the design stage
itself might make the concept of maintenance redundant. All effects should be to devise
schemes so that emergency maintenance remains an exception rather than the rule. With
the ever increasing need for reliable data and information for purposes of criticality
analysis etc., computers might be in greater demand in future to help in more effective
and efficient maintenance management.

13.12 KEY WORDS

Breakdown: Failure resulting in the non-availability of an item.
Corrective Maintenance: Maintenance carried out to restore (including adjustment and
repair) an item which has ceased to meet an acceptable condition.
Downtime: The period of time during which an item is not in a condition to perform its
intended function.
Emergency Maintenance: Maintenance which is necessary to put in hand immediately
to avoid serious consequences.
History Cards: Record of usages, events and actions as appropriate relating to a
particular item.
Maintenance: A combination of any actions carried out to retain an item in, or restore it
to, an acceptable condition.
Maintenance Programme: A list allocating specific maintenance to a specific. period.
Maintenance Planning: Deciding in advance the jobs, methods, materials, tools,
machines, labour, timing and time required.
Maintenance Schedule: A comprehensive list of maintenance and its incidence.
Overhaul: A comprehensive examination and restoration of an item, or major part
thereof, to an acceptable condition.
Planned Maintenance: Maintenance organised and carried out with forethought,
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Operations Planning and Control
Preventive Maintenance: Maintenance carrie 1 out at predetermined intervals, or to
other prescribed criteria, and intended to reduce the likelihood of an item not meeting an
acceptable condition.
Running Maintenance: Maintenance which can be carried out while the item is in
service.
Shutdown Maintenance: Maintenance which can only be carried out when the item is
out of service.
Tero-technology: It is a combination of management, financial engineering and other
practices applied to physical assets in pursuit of economic life-cycle costs; it is
concerned with the specification and design for reliability and maintainability of all
assets, with their installation, commissioning maintenance modification and
replacement, and with feedback of information of design, performance and costs.

13.13 SELF-ASSESSMENT EXERCISES

1 Should maintenance be regarded just as a repair function?
2 What do you understand by the term `tern-technology'? Is the term and concept
easily acceptable?
3 If the trends of computerisation of processes continue to grow, what would be its
impact on the maintenance function?
4 What are the objectives of maintenance management?
5 Can you think of some examples from your experience that either conform to or are
at variance from the `bath tub curve" of failure rate phenomena.
6 What are the different types of maintenance systems? Could you give some
illustrative example for each alternative system? You may take the example of a car,
scooter or any other asset of your choice for elaborating your answer explicitly.
7 What is `priority index' and how would you obtain it?
8 hat precautions should you keep in mind while attempting to apply work study
techniques to maintenance engineering?
9 What is `criticality analysis'? Explain how the Pareto Principle finds its application
for effective maintenance planning and control.
10 Discuss the need for devising some maintenance performance indices.
11 What is the utility of maintenance performance indices? Discuss a few of them.

13.14 FURTHER READINGS

Apte, S., Maintenance Management, NPC: New Delhi.
Aggarwal, S.C. 1968. Maintenance Management, Prabhu Book Service: New Delhi.
Chase R.B. and Aquilano, N.J. 1977. Production and Operations Management: A life
cycle approach, Revised edition, Richard D. Irvin Inc: Chicago.
Chandra, D. 1976. Design out Maintenance and Instrument Aids, Universal Book
Corpn.; Bombay.
Corder, A.S. 1977. Maintenance Management Techniques, McGraw Hill:
New York.
Gradon, F. 1973. Maintenance Engineering, Applied Science Publishers Ltd.:
London.
Kelly, A. 1984. Maintenance Planning and Control, Butterworths Company Ltd.:
London.
Mohanty, R.P. 1984. Works Management, AIMA-Vikas Management Series: New
Delhi.
White, E.N. 1979. Maintenance Planning, Control and Documentation, Second
Edition, Gower Press: London.
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