Maintenance management involves planning and coordinating resources to ensure industrial equipment operates effectively at specified availability levels. It aims to minimize downtime and production losses through planned repair and preventative maintenance. There are different types of maintenance systems like corrective, preventative, and predictive maintenance. The bathtub curve model describes failure rates over equipment lifespan from initial high failure through useful life of constant rate to increasing wear out failures. Key activities involve scheduling maintenance, repairs, inspections, budgeting, and developing maintenance procedures, records, and staff training.

1. MAINTENANCE MANAGEMENT
UNIT 8
Dr. Rashmi Panwar

2. MEANING
• Maintenance activities are related with repair,
replacement and service of components or some
identifiable group of components in a
manufacturing plant so that it may continue to
operate at a specified ‘availability’ for a specified
period.
• Thus maintenance management is associated
with the direction and organization of various
resources so as to control the availability and
performance of the industrial unit to some
specified level.

3. IMPORTANCE
• Maintenance management is responsible for the
smooth and efficient working of the industrial
plant and helps in improving the productivity.
• It also helps to keep the machines/equipment in
their optimum operating conditions. Thus plant
maintenance is an important and inevitable
service function of an efficient production
system.

4. • It also helps in maintaining and improving the
operational efficiency of the plant facilities and
hence contributes towards revenue by decreasing
the operating cost and improving the quality and
quantity of the product being manufactured.
• As a service function it is related with the
incurrence of certain costs. The important
component of such costs are — employment of
maintenance staff, other minor administrative
expenses, investment in maintenance equipment
and inventory of repair components/ parts and
maintenance materials.

5. • Absence of plant maintenance may lead to
frequent machine breakdown and failure of
certain productive centres/services which in
turn would result in stoppages of production
activities, idle man and machine time,
dislocation of the subsequent operations,
poor quality of production, failure to meet
delivery dates of product supply, industrial
accidents endangering the life of workers/
operators and allied costs etc.

6. TYPES OF MAINTENANCE
SYSTEMS
1 - Corrective maintenance
• Corrective maintenance is implemented right
after a defect has been detected on a piece of
equipment or a production line: its objective is to
make the piece of equipment work normally
again, so that it can perform its assigned
function. Corrective maintenance can either be
planned or unplanned depending on whether or
not a maintenance plan has been created

7. 2 - Predetermined maintenance
• Predetermined maintenance, probably the less
known one of all the maintenance types
presented in this article, doesn’t rely on the
actual equipment’s state but rather on the
programs delivered by manufacturers. They
elaborate these programs based on their
knowledge of failure mechanisms as well as on
MTTF (mean time to failure) statistics which they
observed on a piece of equipment and its
various components in the past.

8. 3 3 Condition-based maintenance
• Among all types of maintenance cited above, the condition-based
maintenance is the most complicated to implement. It aims to prevent
failures and requires regular check-ups of the state, the efficiency as well
as other indicators of the system. All this data can be gathered
automatically on the field or remotely thanks to a direct network
connection to the equipment, in order to make sure that it is constantly
controlled. Maintenance teams can decide whether they want to
operate constant or regular interval control: they read counters, check
parts’ wear, control motors’ temperatures… These are all actions the
teams can undertake to ensure that no piece will cause a breakdown
that would damage the whole production line.

9. 4 - Preventive maintenance
• Preventive maintenance is applied by technicians
teams and managers before any breakdown or
failure occurs. Its aim is to reduce the probability of
breakdown or degradation of a piece of equipment,
component or spare part. In order to implement
such maintenance, teams have to take the part’s
history into consideration and keep track of the
past failures. They are therefore able to identify the
time ranges during which a piece of equipment
might break down.

10. 5 - Towards predictive maintenance?
• A next-gen CMMS(computerized maintenance management system) like
Mobility Work, a solution that offers a performing analytics tool able to
gather all the data entered by maintenance teams themselves, aims to
progressively help plants evolve towards predictive maintenance. It allows
technicians to anticipate breakdowns: they generate reports directly in
their maintenance management software, they know when a piece of
equipment might break down and therefore proceed to industrial
maintenance operations. Once again, the most important thing is
anticipation because any failure could slow down the production and
become extremely costly. Predictive maintenance can be implemented
thanks to an intuitive and easy to use CMMS, which will ease industrial
maintenance technicians’ lives and generate tables and graphs for them
thanks to all the data entered by all their colleagues.

11. OBJECTIVES
(1) Minimizing the loss of productive time because of
equipment failure to maximize the availability of plant,
equipment and machinery for productive utilization
through planned maintenance.
(2) To extend the useful life of the plant, machinery and
other facilities by minimizing their wear and tear.
(3) Minimizing the loss due to production stoppages.
(4) To ensure operational readiness of all equipment’s
needed for emergency purposes at all times such as fire-
fighting equipment.

12. • (5) Efficient use of maintenance equipment’s and
personnel.
• (6) To ensure safety of personnel through regular
inspection and maintenance of facilities such as boilers,
compressors and material handling equipment etc.
• (7) To maximize efficiency and economy in production
through optimum utilization of available facilities.
• (8) To improve the quality of products and to improve the
productivity of the plant.
• (9) To minimize the total maintenance cost which may
consist of cost of repairs, cost of preventive maintenance
and inventory costs associated with spare parts/materials
required for maintenance.

13. THE BATH TUB CURVE

14. • The bathtub curve is generated by mapping the rate of early "infant
mortality" failures when first introduced, the rate of random failures with
constant failure rate during its "useful life", and finally the rate of "wear out"
failures as the product exceeds its design lifetime.
• In less technical terms, in the early life of a product adhering to the bathtub
curve, the failure rate is high but rapidly decreasing as defective products are
identified and discarded, and early sources of potential failure such as
handling and installation error are surmounted. In the mid-life of a product—
generally speaking for consumer products—the failure rate is low and
constant. In the late life of the product, the failure rate increases, as age and
wear take their toll on the product. Many electronic consumer product life
cycles strongly exhibit the bathtub curve.
• While the bathtub curve is useful, not every product or system follows a
bathtub curve hazard function, for example if units are retired or have
decreased use during or before the onset of the wear-out period, they will
show fewer failures per unit calendar time (not per unit use time) than the
bathtub curve.

15. • The bathtub curve is widely used in reliability engineering.
It describes a particular form of the hazard function which
comprises three parts:
• The first part is a decreasing failure rate, known as early
failures.
• The second part is a constant failure rate, known as
random failures.
• The third part is an increasing failure rate, known as wear-
out failures.
• The name is derived from the cross-sectional shape of a
bathtub: steep sides and a flat bottom.

16. ACTIVITIES INVOLVED
(1) To develop maintenance policies, procedures and
standards for the plant maintenance system.
(2) To schedule the maintenance work after due
consultation with the concerned production
department
(3) To carry out repairs and rectify or overhaul
planned equipment/facilities for achieving the
required level of availability and optimum operational
efficiency.
(4) To ensure scheduled inspection, lubrication oil
checking, and adjustment of plant machinery and
equipment.

17. (5) To document and maintain record of each maintenance
activity (i.e., repairs, replacement, overhauls, modifications
and lubrication etc.).
(6) To maintain and carry out repairs of buildings, utilities,
material handling equipment’s and other service facilities
such as electrical installations, sewers, central stores and
roadways etc.
(7) To carry out and facilitate periodic inspections of
equipment and facilities to know their conditions related to
their failure and stoppage of production.
(8) To prepare inventory list of spare parts and materials
required for maintenance.

18. (9) To ensure cost effective maintenance.
(10) To forecast the maintenance expenditure and
prepare a budget and to ensure that maintenance
expenditure is as per planned budget.
(11) To recruit and train personnel to prepare the
maintenance workforce for effective and efficient
plant maintenance.
(12) To implement safety standards as required for
the use of specific equipment or certain categories of
equipment such as boilers, overhead cranes and
chemical plants etc.

19. • (13) To develop management information
systems, to provide information to top
management regarding the maintenance
activities.
• (14) To monitor the equipment condition at
regular intervals.
• (15) To ensure proper inventory control of spare
parts and other materials required.