Maintenance strategies document discusses various maintenance approaches and strategies. There are two main maintenance approaches: corrective maintenance which is done after equipment failure, and preventive maintenance which is carried out before failure to prevent it. Some common maintenance strategies discussed are breakdown maintenance, corrective maintenance, preventive maintenance, predictive maintenance, total productive maintenance (TPM), and reliability centered maintenance (RCM). The document provides details on the objectives, types, and elements of each strategy.

1. Maintenance Strategies

2. Maintenance Strategies
• Maintenance strategy is a systematic approach to upkeep the
facilities and equipment and it may vary from facility to
facility
• It involves:
– identification, researching and execution of many
repairs, replace and inspect decisions (Kelly, 1997) and
– is concerned with formulating the best life plan for each
unit of the plant,
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3. Maintenance Strategies
• Basically there are two maintenance
approaches namely:
– Corrective maintenance (CM)
used after failure of equipment is occurred
– Preventive maintenance (PM)
carried away before the failure of equipment
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• Some of the common Maintenance Strategies are:
i. Breakdown Maintenance
ii. Corrective Maintenance
iii. Preventive Maintenance
iv. Predictive Maintenance
v. Total Productive Maintenance (TPM)
vi. Reliability Centered Maintenance (RCM)
Several maintenance approaches (strategies)
have been implemented by practitioners
or suggested by intellectuals

5. 1. BREAKDOWN MAINTENANCE
• In these programs, less concern is given to the operating
condition of critical plant machinery, equipment, or
systems
• Reactive to breakdowns or production interruptions,
and only focus on how quickly the machine or system
can be returned to service
• As long as the machine will function at a minimum
acceptable level, maintenance is judged to be effective.
• high maintenance costs:
– (1) poor planning and
– (2) incomplete repair.
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6. 2. Corrective Maintenance
• is an unscheduled maintenance action, basically
composed of unpredictable maintenance needs
that cannot be preplanned or programmed on the
basis of occurrence at a particular time
• The action requires urgent attention that must be
– added, integrated with, or substituted for previously
scheduled work items.
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7. CORRECTIVE MAINTENANCE TYPES
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8. CORRECTIVE MAINTENANCE TYPES
• Fail- repair: The failed item is restored to its
operational state.
• Salvage: This element of corrective maintenance is
concerned with disposal of non-repairable material
and use of salvaged material from non-repairable
equipment/item in the repair, overhaul, or rebuild
programs.
• Rebuild: This is concerned with restoring an item to
a standard as close as possible to original state in
performance, life expectancy, and appearance.
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9. • Overhaul: Restoring an item to its total
serviceable state as per maintenance
serviceability standards, using the “inspect
and repair only as appropriate” approach.
• Servicing: Servicing may be needed because
of the corrective maintenance action,
• for example, engine repair can lead to crankcase refill,
welding on, etc.
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10. Five major sequential steps of corrective maintenance
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11. Active Repair Time
• he active repair time is made up of the
following subcomponents:
– Preparation time
– Fault location time
– Spare item obtainment time
– Fault correction time
– Adjustment and calibration time
– Checkout time
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12. 3. Preventive Maintenance (PM)
• PM may be described as
– the care and servicing by individuals involved
with maintenance to keep equipment/facilities in
satisfactory operational state by providing for
• systematic inspection,
• detection, and
• correction of incipient failures either prior to their
occurrence or prior to their development
into major failure
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13. Main Objectives of PM
• Enhance capital equipment productive life,
• Reduce critical equipment breakdowns,
• Allow better planning and scheduling of needed
maintenance work,
• Minimize production losses due to equipment
failures, and
• Promote health and safety of maintenance
personnel.
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14. Seven Elements of PM
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15. Seven Elements of PM…
1. Inspection: Periodically inspecting materials/items to determine
their serviceability by comparing their physical, electrical,
mechanical, etc., characteristics (as applicable) to expected
standards
2. Servicing: Cleaning, lubricating, charging, preservation, etc., of
items/materials periodically to prevent the occurrence of
incipient failures
3. Calibration: Periodically determining the value of characteristics
of an item by comparison to a standard; it consists of the
comparison of two instruments, one of which is certified
standard with known accuracy, to detect and adjust any
discrepancy in the accuracy of the material/parameter being
compared to the established standard value
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16. Seven Elements of PM…
4. Testing: Periodically testing or checking out to determine
serviceability and detect electrical/mechanical-related
degradation
5. Alignment: Making changes to an item’s specified variable
elements for the purpose of achieving optimum performance
6. Adjustment: Periodically adjusting specified variable elements
of material for the purpose of achieving the optimum system
performance
7. Installation: Periodic replacement of limited-life items or the
items experiencing time cycle or wear degradation, to
maintain the specified system tolerance
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17. 4. PREDICTIVE MAINTENANCE
• Predictive maintenance is a management technique that, uses
regular evaluation of
– the actual operating condition of plant equipment,
– production systems, and
– plant management functions to optimize total plant operation
• The output of a predictive maintenance program is data.
• Until action is taken to resolve the deviations or problems
revealed by the program, plant performance cannot be
improved
• Therefore, a management philosophy that is committed to
plant improvement must exist before any meaningful benefit
can be derived.
• Properly used, predictive maintenance can identify most, if not
all, factors that limit effectiveness and efficiency of the total
plant.
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18. QUALITY IMPROVEMENT
• Most product quality problems are the
direct result of
1. production systems with inherent problems,
2. poor operating procedures,
3. Improper maintenance, or
4. defective raw materials.
– Predictive maintenance can isolate this type of
problem and provide the data required to correct
many of the problems that result in reduced
product quality.
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19. QUALITY IMPROVEMENT…
• A comprehensive program will use a combination of
data, such as:
– Vibration,
– Thermography,
– Tribology
– Process parameters, and
– operating dynamics,
• to anticipate deviations before they can affect
– product quality,
– production capacity, or
– total production costs
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20. PREDICTIVE MAINTENANCE TECHNIQUES
• There are a variety of technologies that can and should
be used as part of a comprehensive predictive
maintenance program
– These techniques include
1. Vibration monitoring,
2. Thermography, monitor the emission of infrared energy (i.e., Surface
temperature) to determine operating condition
3. Tribology, (the science of friction, wear, and lubrication of interacting surfaces),
4. Process parameters,
5. Visual inspection, and
 Other nondestructive testing techniques.
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21. Considerations of Inspection
• All machinery inspection should be based on these
considerations:
1. Expected failure experience:
 Deterministic
 Probabilistic
2. Inspection cost.
3. Probability and risk of failure.
4. Probable consequences of failure, i.e., safety-health and
business loss.
5. The risk that inspection will cause a problem
6. The quality of on-stream condition monitoring results.
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22. Preventive vs. predictive-maintenance
 The fundamental difference between preventive
maintenance and predictive- or condition-based
maintenance strategies is that:
Preventive Maintenance is carried out as soon
as a predetermined interval has elapsed,
while condition-based maintenance requires
checking at predetermined intervals, with the
maintenance action carried out only if
inspection shows that it is required.
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23. Main factors in a predictive
maintenance program
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The main factors in a predictive machinery
maintenance program are:
State-of-the-art (the level/quality of) instrumentation
and monitoring methods
Skilled analysts
Information system allowing easy data retrieval
Flexible maintenance organization allowing for an
easy operations/ maintenance interface
Ability to perform on-line analysis

24. 5. Total Productive Maintenance (TPM)
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 TPM is maintenance activities that are productive and
implemented by all employees.
 Aims at building up a corporate culture that thoroughly
pursues production system efficiency improvement or overall
equipment efficiency(OEE)
Creates a system to prevent every kind of loss,
for example, to achieve zero accidents, zero defects, and zero failures, based
on “actual site” and “actual object” over the entire life cycle of a production system
TPM involves everyone in the organization from operators to
senior management in equipment improvement.
Achieves zero losses by overlapping small-group activities
 It encompasses all departments including:
•Maintenance • Operations
•Facilities • Design Engineering
•Project Engineering • Construction Engineering
•Inventory and Stores • Purchasing
•Accounting and Finance • Plant and Site Management

25. Goals of TPM
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TPM has the following five goals (some
texts call these pillars):
1. Improving equipment effectiveness
2. Improving maintenance efficiency and
effectiveness
3. Early equipment management and maintenance
prevention
4. Training to improve the skills of all people
involved
5. Involving operators (occupants) in routine
maintenance

26. EIGHT PILLARS OF TPM
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In TPM, to achieve targets effectively and efficiently,
eight pillars have been adopted.
These pillars are activities that are cross-functional.
1. Focused improvement
a) The aim of this activity is to acquire the ability
to discover and solve problems of equipment
losses.
b) Important subjects
i. Elimination of the six major chronic losses
ii. Substantial cost reduction
iii. The improvement of management
techniques and engineering techniques

27. EIGHT PILLARS…
2. Autonomous maintenance
a) The aim of this activity is to restore deteriorated equipment
and establish a system whereby the operators think and act in
terms of “We take the responsibility to protect our own
equipment.”
b) Important subjects
I. Establishment of 2S
a) Sort. Eliminate the unnecessary
b) Stabilize. Establish permanent locations for the essential
II. Steady development of the autonomous maintenance
III.Improvement of the maintenance skill of operators
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28. EIGHT PILLARS…
3. Planned maintenance
a) The aim of this activity is the improvement of conventional
maintenance capabilities, preventing breakdowns, and reducing
maintenance costs
b) Important subjects
i. Support for autonomous maintenance and focused improvement activities
ii. Realization of “no sudden malfunctions” by promoting corrective
maintenance/periodic Maintenance
iii. Enforcement of predictive maintenance through development of diagnostic technology
4. Education and training
a) The aim of this activity use skilled people to handle equipment and operations
b) Important subjects
i. Promotion of maintenance skill training and office automation skill education
ii. Establishment and promotion of a skill development program
iii. Upgrading and improvement of the education and training system
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29. EIGHT PILLARS…
5.Initial management
a. The aim of this activity
Based on maintenance prevention(MP) design, establish a highly reliable, maintainable, and economical
system.
b. Important subjects
(1) Collection and usage of MP information
(2) Development of a “concurrent operation” system
(3) Promotion of equipment development which fully considers life cycle cost
6.Quality maintenance
a. The aim of this activity is to acquire the control capability of a “cause system” which
is superior to that of a “results system,” and thus achieve “zero defects”
b. Important subjects
(1) Elimination of customers’ claims
(2) Realization of no defects originating from equipment or people
(3) Establishment and maintenance of optimal 4M conditions (man, machine, materials, and methods),
including selection of settings
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30. EIGHT PILLARS…
7.TPM for indirect office work
a. The aim of activity
(1) Reduction of indirect work and its cost
(2) Improvement of quality of service to customers and/or the production division
b. Important subjects
(1) Clarify purpose. Elimination of method losses and human losses
(2) Simplification of operations, and sharing of knowledge
(3) Improvement of service to customers and/or the production division
8.Management of safety, health, and environment
a. The aim of this activity is the achievement of a workplace environment which
is safe, bright, and easy-to-work-in
b. Important subjects
(1) Realization of no accidents and no pollution
(2) Reduction of noise, humidity, and the like
(3) Achieve a complete “healthy workplace” environment
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31. Equipment usage loss
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32. • The maintenance function must ensure that all
production and manufacturing systems are
operating safely and reliably and provide the
necessary support for the production function.
• Furthermore, maintenance needs to achieve its
mission using a cost-effective maintenance strategy.
– United Airlines revealed that scheduled overhaul did not have much
impact on the overall reliability of a complex item unless there is a
dominant failure mode.
– only 11% of the components exhibit a failure characteristic that justify
a scheduled overhaul or replacement.
– Therefore, new thinking is required to deal with the remaining 89%.
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6. Reliability Centered Maintenance (RCM)

33. Reliability Centered Maintenance
(RCM)
• It is a methodology that determines what must be done to
ensure that the asset continues fulfilling its intended
functions in its present operating context.
• A process or system to evaluate equipment and develop
preventive maintenance tasks and frequencies to
reduce likely failure modes
• The goal of these programs is to provide the
appropriate amount of maintenance at the right time
to prevent forced outages while at the same time
eliminating unnecessary maintenance.
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34. Seven Basic Questions
• RCM process asks seven basic questions from which a
comprehensive maintenance approach can be defined:
1. What are the functions and associated performance standards of the asset
in its present operating context?
2. In what ways can it fail to fulfill its functions?
3. What causes each functional failure?
4. What happens when each failure occurs?
5. In what way does each failure matter?
6. What can be done to predict or prevent each failure? and
7. What should be done if a suitable proactive task cannot be found?
 From these seven questions emerges a systematic process to determine the
maintenance requirements of any physical asset in its operating context, called
Reliability Centered Maintenance.
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35. systematic process to determine the
maintenance requirements
• The first step in the RCM process is to define the functions of each
asset in its operating context
• Then identify what failure can occur and defeat the functions.
• the next step is to try to identify the causes of failures (failure
modes).
• The fourth step in the RCM process involves listing failure effects.
– The RCM process classifies these consequences into four
groups, as follows:
• Hidden failure consequences;
• Safety and environmental consequences;
• Operational consequences; and
• Non-operational consequences.
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36. RCM Principles
1. Preserving the system function
2. Identification of the particular failure modes
that can potentially cause functional failure
3. Prioritizing key functional failures
4. Selection of applicable and effective
maintenance tasks for the high priority items
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37. Some features of RCM are:
• Labor intensive and time consuming to set up initially.
• May require additional monitoring of quantities like
temperature and vibration to be effective. This may mean new
monitoring equipment with its own PM or more human
monitoring with multiple inspections.
• May result in a “run-to-failure” or deferred maintenance
philosophy for some equipment with its own PM, which may
cause concern for some staff and managers.
• May require initial and later revisions to the maintenance
schedule in a “trial-and-error” fashion depending on the success
of the initial maintenance schedule and equipment condition.
• Should result in a more manageable maintenance workload
focused on the most important equipment.
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38. Selection of maintenance strategy
• Selecting the best maintenance strategy
depends on several factors such as:
– the goals of maintenance,
– the nature of the facility or
– the equipment to be maintained,
– work flow patterns (process focus, product
focus), and
– the work environment.
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39. Selection of maintenance strategy…
• Maintenance strategy selection has been studied
extensively where various decision making
approaches were proposed based on multiple criteria
• Various multi-criteria decision making approaches
have been proposed for maintenance strategy
selection such
– as Analytic Hierarchy Process (AHP),
– fuzzy set theory,
– Genetic Algorithm (GA),
– mathematical programming,
– factor analysis,
– simple multi-attribute rating technique (SMART)
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