2. Definition:
A formal definition of maintenance is “that function of
manufacturing management that is concerned with day
to day problem of keeping the physical plant in good
operating condition”
3. Objectives:
Minimize loss of productive time
Minimize repair time & cost
Keep productive assets in working
condition
Minimize accidents
Minimize total maintenance cost
Improve quality of products
4. Importance:
Dependability of service
Assured quality
Prevent equipment failure
Cost control
Huge investment in equipment
5. Areas of Maintenance:
1. Civil maintenance- Building construction and maintenance, maintaining
service facilities
2. Mechanical Maintenance- Maintaining machines and equipments, transport
vehicles, compressors and furnaces.
3. Electrical Maintenance- Maintaining electrical equipments such as
generators, transformer, motors, telephone systems, lighting, fans, etc.
6. Reasons for Maintenance
Maintenance serves to protect the owners’ real estate
investment in a number of ways
Physical Integrity
To keep the assets in good working order so as to minimize
disruptions and downtimes.
7. Risk Management
To keep the assets in a state of good repair for the owners’ health and safety.
Aesthetic Preservation
To keep the assets from deteriorating in appearance and becoming unsightly.
Responsible Stewardship
To ensure that the assets achieve their full potential service life.
8. Duty of Care
To satisfy a legislated duty that is owed to owners,
occupants and guest on the property.
Duty to Mitigate
To prevent unnecessary damage to assets that may result in
their premature failure.
10. Break Down Maintenance
It means that people waits until equipment
fails and repair it. Such a thing could be used
when the equipment failure does not
significantly affect the operation or production
or generate any significant loss other than
repair cost.
Preventive maintenance
It is a daily maintenance ( cleaning,
inspection, oiling and re-tightening ), design to
retain the healthy condition of equipment and
prevent failure through the prevention of
deterioration, periodic inspection or
equipment condition diagnosis, to measure
deterioration.
11. Predictive maintenance
This is a method in which the service life of
important part is predicted based on
inspection or diagnosis, in order to use the
parts to the limit of their service life.
Compared to periodic maintenance, predictive
maintenance is condition based maintenance.
It manages trend values, by measuring and
analysing data about deterioration.
12. Condition Monitoring
Condition monitoring is the process of
determining the condition of machinery while
in operation.
The key to a successful condition monitoring
programme includes:
1. Knowing what to listen for
2. How to interpret it
3. When to put this knowledge to
use
Successfully using this programme enables
the repair of problem components prior to
failure.
Condition monitoring not only helps plant
personnel reduce the possibility of
catastrophic failure, but also allows them to
order parts in advance, schedule manpower,
and plan other repairs during the downtime.
13. Corrective maintenance
It improves equipment and its components
so that preventive maintenance can be
carried out reliably. Equipment with design
weakness must be redesigned to improve
reliability or improving maintainability
14. Advantages And
Disadvantages
Break Down Maintenance
Advantages Disadvantages
Lower start up cost Unpredictability
Limited personnel requirement Equipment not maximised
Reduced maintenance costs Indirect costs
Potentially increased margins
15. Preventive Maintenance
Advantages Disadvantages
Over all very cost effective Catastrophic failure still a risk
Flexibility can allow for adjustment of
schedule to accommodate other work
Labour Intensive
Increased equipment life Performance of maintenance based on
schedule not required
Saved energy cost resulting from
equipment running from pick efficiency
Risk of damage when conducting
unneeded maintenance
Reduced equipment or process failure Saving not readily visible without a base
line
Over all saving between 12% to 18%
16. Predictive Maintenance
Advantages Disadvantages
Increased component operational
life/availability
Increased investment of diagnostic
equipment
Allows for pre-emptive corrective action Increased staff training for analysing
data
Decreased part and labour cost Saving not readily visible without a
baseline/history
Improved safety and environment
Energy savings
Over all saving between 8% to 12%
over preventive maintenance
17. Condition Monitoring
Advantages Disadvantages
Extend bearing service life Monitoring equipment costs
Maximise machine productivity Operational costs (running the
program)
Minimise unscheduled downtime Skilled personnel needed
Safely extend overhaul intervals Strong management commitment
needed.
Improve repair time A significant run-in time to collect
machine histories and trends is usually
needed.
Increased machine life
Improve product quality
Reduce product cost
Enhance product safety
18. Corrective Maintenance
Advantages Disadvantages
Lower short-term costs Increased long-term costs due to
unplanned equipment downtime.
Requires less staff since less work is
being done
Possible secondary equipment or
process damage.
Prone to neglect of assets
19. Opportunistic Maintenance: – In multi component system, several failing
components, often it is advantageous to follow opportunistic maintenance. When
an equipment or system is taken down for maintenance of one or few worn out
component, the opportunistic maintenance can utilize for maintaining or changing
other wear out components, even though they are not failed. -It is actually not a
specific maintenance system, but its a system of utilizing an opportunity which may
come up any time.
Corrective Maintenance – Maintaining action for correcting or restoring failed
unit.
- Very vast scope for small actions like adjustment, minor repairs to redesign of
equipments
- Generally once taken and completed fully Usually carried out in four steps :
1st step : collection of data, information and Analysis
2nd step : identifying the causes
3rd step : find out the best possible solution to illuminate likely causes
4th step : Implement those solutions
20. Shutdown corrective maintenance which is a set of corrective
maintenance activities that are performed when the production
line is in total stoppage situation.
Design-out maintenance which is a set of activities that are used
to eliminate the cause of maintenance, simplify maintenance
tasks, or raise machine performance from the maintenance point
of view by redesigning those machines and facilities which are
vulnerable to frequent occurrence of failure and their long term
repair or replacement cost is very expensive.
Engineering services which includes construction and
construction modification, removal and installation, and
rearrangement of facilities.
Shutdown improvement maintenance which is a set of
improvement maintenance activities that are performed while
the production line is in a complete stoppage situation.
