Maintenance Management, as support function to the production operations and to the service

operations, is very important. It has atremendous impact on the condition of the plant and machinery in
the factories and the equipment that may be used in the service industry. For example, in a continuous
process plant such as a petroleum refinery if there is atbreakdown in one section, it may immediately
affect the entire operation downstream and the other operations a little while later. If it is batch operation,
breakdowns may damage the condition of the batch of materials in production or it may disturb the
schedules of various batches to be produced, thereby leading to considerable confusion. Breakdowns and
slowdowns are quite unwelcome, anywhere. In a software services industry or in a call centre, the
functioning of the telecommunication and transmission equipment is vital to their business. The lack of
good maintenance could be disastrous.
medical doctors might say that the importance of maintaining good health is generally not fully
realized by many people until they happen to fall sick, similarly the importance of Maintenance
Management is not adequatelý realized by the industry. This is particularly true of the Indian industry. In
several factories, scant attentíon is paid to the proper stocking of the spare parts, tò maintaining proper
policies and procedures, to have appropriate preventive maintenance schedules, tß have updated
maintenance manuals, to the acquisition and development of required number andquality of technicians
and junior and senior managers who may have appropriate skills to operate and maintain the modern
equipment properly, and to the application of the principles of work study, incentives and performance
evaluation tothe extent possible. Maintenance management is perceived to be ofsecondary importance
to the production of goods. In the serviceindustry, it has asimilar or even less importance.
There is a general lack of management input in maintenance. The reasons given by many for the same
are:

Machine failures occur at random and are, therefore, unpredictable.

2rOne maintenance job is not like another maintenance job so as to put it in a standard category.
3 Different types of equipment are imported at different times, resulting in aheterogeneous stock of
equipment; this makes it difficult to provide proper skilled manpower and facilities for mainte
nance and repair.
 difficult: making them
Obtaining spare parts from foreign countrics is within
difficult the country
4. small. It is
conomical since the quantity requircd of cach item is
circumstances. to apply is y
such
principles and generate economies in
True. the above given explanations are some of
the real problems in
applying management
techniques to maintenance: the last twO reasons are parucular1y rue Tor developing couPincin.
of having good maintenance
man germenm
India. But then. looking atthe quantum of positiveimpactmanagement
factory or in an operations
need to
facility,the nced for proper
make best us of the management concepts available
of
maintenance
is
even if the circumstances
do man¡tnageasmealnsto the.
vital in a

application in toto. Good maintenance management is an

importantinput for achieving the
following paragraphs, wÁ will discuss the
peTmi
desired t thejy
of the products and services. In the
techniques of management useful in maintenance.
concepts, principleqsuaityand
MANAGEMENT:
PRIMARY OBJECTIVEOF MAINTENANCE
AVAILABILITY OF THE OPERATIONS SYSTEM
The objective of maintenance is to facilitate the optimaluse ofcapital equipmentthroughaactions:
that
modification of the components oF machinery so these
replacement, repair, service and
for as long as it is beneficial to do so. Maintenance wil .contimue
o operate
keeping at a specified availability
encompasSeS
the ´¡vailability ofthe entire production/operations system of the organisation. One ofithe basic
definitions of 'availability is as follows:
Availability running
(over a specified time) + tdown
Irunning normal operating state.
where Irunning = Total time of operating in the
time for which the plant (or equipment) is out of operatioaeither
and ldown Total service or waiting for it.
because it is being given maintenance

availabilitybf aplant can be improved by various means, such as:

The
faults or failures as early as possible and taking quick decisions regarding the
1. Diagnosing the
same. j crisis situations with the help of appropriately organised prever.
2. Reducing major break-downs or
tive maintenance programmes;
equipment in sucha way that the failures, of the equipment wille ****

3. Designing and Installing the increasing what is known as the reliability of the plan,
over its lifetime or in other words, be so designed
Tow
equ'pment in the design stages itself. Also, the equipment could high.
machinery and the 'maintainability' should be
action are small ie.
that the times for maintenance component parts in such a way tha
proper replacement policies of equipment and their
4. Having
ayailabiljy of the system is enhanced at optimal costs.
the total reliabilityand maintenance as much as possible, so as to gal
Having standard times and standard procedures in adequate incentives and motivaion
5. operations and also to provide
goodcontrol over maintenance
for maintenance personnel.
Reliability Engineering
reliability Reliability is defined as thelor
is the topic of
Closely connected to failure statistics particular period of time under-specified
fa plant to give satisfactory
performance in a operating
and more important because the
conditions
reliability which is fairly new, is becoming more sophistication, failures
The subject of by day. With increasing
complexity of equipment and plants is growingday poa.
nuciear Tedctors, Superthermal power
sometimes catastrophic as in the case oI
become more critical and
stations, automated chemical plants, etc. predict the lite of plant and equipments, the availabilityn8
forecast or required. The amount of mainten
It is becoming necessary to expected maintenance work
the
plant and equipment, andthereby will depend upon the reliability of the system and the svstem
work, either preventive or breakdown and the system components are known and calculated aheod
system
components. If the reliabilities of the fairly well estimated and alocated with respect to fims
maintenance can be
of time, then the workload for equipment. Reliability estimates will provide guidance in
machinery and
and with respect to different machines. Reliability figures will help in deciding when to replac.
stocking the spare parts and stand-by calculations will tell what improvements in the
design of
machines and components. Reliability acceptance.
make the probability of failure low enough for
equipment and total plant system would upon the design of the equipment. Of course, it also partially
Reliability of equipment depends much for the equipment is carried out. Additionally, reliability of
maintenance
depends on how the preventive system, that is, the way various equipment are
linked
design of the plant
a plant depends upon the
functionally) with each other.
PREVENTVE MAINTENANCE
Planningfor maintenanceis one of the important jobs of the Maintenance Manager Planned maintenance
altermativelyknown as Preventive Maintenance. It includes the following:
0s care of the
tsual equipment, such as lubricating, cleaning, adjusting/resetting the equipment or
narts while the equipment iseither idle or running.
a Periodicinspection or overhaul of the equipment and scheduled replacement of parts.
iCoñtingent work done at regular intervals when the equipment is down. For instance, in chemical
plants the rotary kilns, the multiple effect evaporators, large vessels, the thickners and the reac
tion tanks are all inspected for their various parts, linings, etc. when these equipments are down.
Situtn
 Contingency work is particularly cncountered in chemical plants which operate on a conti.
(iv) hasis.yhuut
(roRiONn Monitoring is a ncw technique where high cost critical equipment are
Imuously or at frequent periodic intervals to observe the values of various parameters monitored
the conditiòn of thecquipment and the components within.
The parameters being monitored may be (af temperature, (b) vibration, (( noise, (4} refleching
(e) corrosion, for lubricant,
malfunctions such as coolant failure, damaged bearing, damaged insulation, improper heat instance,
build-up of sediment or dust or corrosion by-products in the equipment, etc. Vibration
analysis may point out faults such as misalignment, imbalance in rotation, bend and
genertorinag:tioandn,
moni
shaft, damage inthe gears, vanes, tubes, hysteresis whirl, etc. Lubricant monitoring might assymmetry in the
indicate
or rate of wear of components and the type of wear (whether abrasion or cutting or surface fatigielwear
Thus, much indicative information is given by condition monitoring. The information coma. .
advance of the probable major failure which is the most important benefit of condition
high cost and/or critical machinery,where one can ill afford a breakdown, this monitoring system isFormonitoring,
immense value. The cost of such monitoring is high, because of the requirement of sophistictw
monitoring/measuring instruments. But, the high cost is justified or more than compensated in severl
cases.

Benefits from Preventive Maintenance

The benefits from preventive maintenance are:

Reduction of the total down-time and consequent reduction in production losses.
Reduction in the number of major repairs, and consequently reduced maintenance expenses.
Reductionin the number of rejects and an improvement in product quality.
YReduction in the inventory of spare parts.
Reduction in the number of accidents in the plant.
Reduction in the unplanned or crisis management in maintenance.
besides the benefits mentioned above, there are certain costs associated with the preventive
maintenance programme. The costs are those of:
" Scheduled down-time of production.
Replacement parts and supplies.
Instruments e.g. in the case of condition monitoring.
Wages of preventive maintenance technicians and staff.
" Minor costs such as those of record-keeping.
has to t:
It follows, therefore, that too much or too little of preventive maintenance is not good. There
a balance in the allocation of resources topreventive maintenance and Kreakdown maintenange.
NOt d
preventive
items can be scheduled for preventive maintenance, neither can all the time be spent
on
maintenance only. plant's needs. The needs
Each plant should have its own preventive maintenance policies suited tothat
working environment, the type of operations,thetype of
are based on comparative cost criteria. The
determine the incidence of breakdow
equipment, the age of equipment and plant, and other factors of the
preventive
their severity, and the costs associated with these in the absence or presence as to whatshouldbe
and fast rule
maintenance programme of asmaller or larger size. There is no hard
 on preventive
timespent on
preventive maintenance as opposed to breakdown maintenance. In general, plants
thetotal maintained efficiently spend almost three quarters of their time on preventive maintenance,
ahchare breakdown maintenance.
only one quarter is spent on br
whiledesigning a preventive maintenance prograrmme, the failure statistics will be of much use. The
In tthefailure,the the reliabilities, combined with the costs of avoiding or delaying failures
natureof
preventiveaction as against the
the costs of emergency breakdown will determine the
b iextent of preventive action. One may treat the failures as the arrivals or arriving frequency, nature
customers in the
nu Theory model. The behaviour of servicing times may also be gathered as past data. With an
dnumber of servers (servicing capacity such as the number of mechanics/technicians), the delays
ingtimes of breakdowns may be computed. The costs of different strategies, with
kor of technicians in both categories of maintenance, may be compared in order to
different total
arrive at an
oatimum total number and mix of the resources in the two categories of maintenance.
Itis important to include in the cost data, the estimates of costs of safety to the workers and the costs
of rejects or low quality output.
TOTAL PRODUCTIVE MAINTENANCE (TPM)
presented so far have had one basic thread of
The concepts of maintenance
running throughout:
management
that failure of breakdowns are inevitable.
Hence the trade-off or compromise assumption
maintenance; or, hence the computatio
between the preventive maintenance and the breakdown
attitude, it leads to compromises in
optimal stock of spare parts. Once there is a compromising quality also may break down anda
the
areas. For instance, if the machines do break down, then
deliveries may get upset. management by ceaselescl.
On this score, the Japanese have shown a new path to the world of
defectives. During 1971
working towards the ideal goals of zero breakdown and zero defects or zero
level. It will
1982 the accidental breakdowns in Japan decreased drasticatty to l per cent of the original
considerahly
not be incorrect to say that the quality guru, Philip Crosby's goal of zero defects is helped
breakdown of machinery, the les
by the Japanese concept of the pursuit of zero breakdowns. Less the
would be the proportion of etective quatity Breakdewn of equipment can occur in the following
different ways.
time, set-up and
1. Equipment stops performing its function. So, there are downtime losses of repair
adjustment time.
2. Equipment deteriorates and its performing ability is diminished leading to a reduction infunction
such as a reduction in the speed of the equipment leading to speeds and/or yields lower than designed. O,
the equipment keeps having minor stoppages and/or produces more defectives.
situation is reached.
3. Equipment bas bidden defects which do not become apparent until the breakdown
This is the
All these types of breakdowns have to be eliminated. There is no room for trade-offs.
rationale behind the Total Productive Maintenance (TPM). The objective of TPM is much wider thal
just minimising equipment downtime; the objective is to minimize the life cvcle costsie. the costs tor h
entire lifespan of the equipment (here, by lifespan one means the time until the equipment gets obsoleie
Tn theearlier sections of this chapter, we only looked at the profitability or advantages gained
The proactive
Preventive Maintenance (PM). Still, this is only a reactive approach to management.
approach is Maintenance Prevention (MP) i.e. having a maintenance-free design. Stoppages of eu
Aind Bnakdown Maintenance (BM) or Preventive
Maintenance
problem whould neither be removcd at the flower'(PM)-are time-wasters and are not
. 7he
kesirable. should not 0CCUr. stage, nor at the bud' stage: the
in thefirst plave,
This proaCtivily
yoblem, can be helped significantly if all the concerned people participate actively. Hence,
1"Mincludes:
Optimisingcquipment elfcctiveness by climination of all types of brcakdown or
losses, detects
and other wastes in operation. failures, speed
(ii) Autonomous Majntenance by operalors, Wwhich
mcans the people who operate the
look r
afierttheir machines by themselves. This would
mcan training and
machines will
fors. The
idea is that the operating people would gct to know
their involvement of the opera-
will be contribute only in
able to not cquipment even better so that
theye prevention of maintenance itselTmaintenance
of the preventive and
through their
breakdown kind but
machines, processes, systems, materials and products.
suggestions for improved designs of
Conpany-wide involvement ofaall employees through smnall
group
(ii) CoNe Such
partiç1pative management would enhance creativeactivities
thinking
which would support
and cross-flow of
inforination, ( Continuous improvement t comes through such
Thefollowing
Table 13.3 depicts the progression in the field of participative processes.
Maintenance Management.