Mm

The Maintenance Management
Guide
© Imants http://www.managementsupport.com

Guide
1. Introduction

1. Maintenance Management
1.1 Definitions (1)
Asset
Any item of physical equipment

1.2. Definitions (2)
Asset function
- What users expect from their assets
(output, speed, safety, environmental
integrity, quality ..)
- The level of performance which the
users require when the asset does
its function

Asset failure
Situation where the asset is no
longer capable of fulfilling one or
more of its intended functions

Maintenance
Any activity carried out on an asset in
order to
- ensure that the asset continues to
perform its intended functions
- repair the asset

Maintenance management
The coordination, control, planning,
execution and monitoring of the right
equipment maintenance activities of
manufacturing operations

2. Objectives
• Preserve asset functions
• Avoid the consequences of failure of the
asset
• safety failures: endanger personnel and
equipment
• operational failures: result in product loss and
cost of repair
• non-operational failures: result in cost of repair

3. Evolution (1)
• Availability
• time available for production - downtime
time available for production
• = a measure of the equipment uptime
• Reliability
• the probability that equipment will not fail in a
given time period
• = a measure of the frequency of downtime
Definitions

1.3. Evolution (2)
Expectations of the maintenance function
Higher availability
Lower costs
Longer asset life
1930 - 1950 1950 - 1980 1980 - 2000
Higher availability
Lower costs
Longer asset life
Higher reliability
Better product quality
Safety integrity
Environment integrity
Show results
Fix it when it
breaks

1.3. Evolution (3)
Maintenance techniques
Scheduled
maintenance
Planning systems
Computerization
1930 - 1950 1950 - 1980 1980 - 2000
Condition monitoring
Failure modes and
effects analysis
Computerized Maint.
Management Systems
RCM - TPM (see later)
Fix it when it
breaks

Guide
2. Maintenance Management Functions

2.1. Overview
• Physical assets management
• identification of assets
• recording of information
• Maintenance strategy determination
• conducting the right maintenance
• Maintenance planning & scheduling
• work order management
• Resources management
• people, spare parts, tools
• Performance measurement

Guide
Physical assets management

2.2. Physical Assets Management
• Maintenance is concerned with Assets
• Preservation of asset functions
• Renovation of assets
• Life extension of assets
• Replacement of assets

Maintenance Management Functions
• Assets must be identified
• use an asset hierarchy to identify your assets
• example
• plant
• area (packing area)
• equipment (belt conveyor)
• item (gear box)
• part (bearing)
• standardize the equipment descriptions

• Asset information must be recorded
• record all equipment maintenance activities
• assign all maintenance costs
• establish and effectively use a documented
history for each equipment

Guide
Maintenance strategy determination

2.3. Maintenance strategy determination
Fix it when it fails
Preventive maintenance
Condition based Predictive maintenance
Emergency maintenance
Corrective maintenance
Strategy Maintenance type
Time based (calendar time
or running time)
Equipment redesign Modification maintenance
Failure finding Routine maintenance

How can we assure that the maintenance
conducted is the right maintenance and that
it produces the required equipment
reliability?
Reliability Centered Maintenance
(RCM)

RCM is a technique for reviewing equipment
failures and for determining the right
maintenance tasks
RCM definition

• RCM ensures that all performed maintenance
is cost effective
• RCM contradicts the traditional precepts that
the reliability of equipment is directly related
to operating age
• RCM focuses on preserving the functions of
equipment, not on preserving the equipment
itself
RCM properties

• Select the most critical equipment
• Determine the functions of the equipment
• Establish performance standards
• Determine type of failures
• Identify causes of failures
• Define effects of failures
• Categorize the effects of failures
• Identify appropriate maintenance tasks
• Establish an overall maintenance plan
RCM steps

• Operations
• identifies the functions and performance standards
• Maintenance
• identifies the types of failures
• defines the most appropriate condition monitoring
techniques
• builds a program
• Maintenance and operations
• collaborate on the consequences of identified failures
• carry out the program
RCM implementation

• A part of equipment has suffered a failure when it is
no longer capable of fulfilling one or more of its
intended functions
• A failure mode or cause is any event which causes a
failure
• A failure pattern is the relationship between the
probability of failure of an item, and its age
• There are six distinct failure patterns, one of which
is the bathtub curve
Some important notes about failures

Operating time
Probability
of failure
Manufacturing
& installation
defects
Useful Life Period Wear-out Period
Bathtub curve

A (bathtub curve)
- starting with manufacturing and installation defects,
going to constant failure probability, ending in a
wear-out zone
- example: new machines
Failure patterns

B
- constant failure probability, ending in a wear-out
zone
- example: abrasion
Failure patterns

C
- slowly increasing probability of failure
- no identifiable wear-out age
- example: fatigue
Failure patterns

D
- low failure probability when the item is new
- rapid increase to a constant level
Failure patterns

- constant failure probability at all ages
- example: rolling element bearings
E
Failure patterns

- starts with high failure probability
- drops to a constant level
F
Failure patterns

• The most appropriate equipment
maintenance strategy can be determined by
• The failure pattern that applies to a given failure
mode
• Mean Time between Failures (MTBF): the number
of failures in a given time period, divided by the
time that the equipment was operating in that
period
• FMEA (Failure Mode and Effects Analysis):
identify all the events which are reasonably likely
to cause each failed state

• Definition:
• maintenance work requiring immediate response
from maintenance employees
• Goal:
• solve downtime, safety risk, danger or damage
• Properties:
• unplanned
• creates peaks and valleys in the work load
• expensive
• requires emergency spare parts purchasing
Maintenance types: emergency maintenance

• Definition:
• restoring an asset to a preserved condition
• Goal:
• improve quality or performance
• Properties:
• planned
• a work order has been created
• the work is prepared
Maintenance types: corrective maintenance

• Definition:
• replacements or overhauls scheduled on elapse
of calendar time or elapse of running time
• Goal:
• reduce downtime and breakdowns
• extend the life of the equipment or system
• Properties:
• planned & prepared
• correct failure probability must be known
• original reliability must be restored
Maintenance types: preventive maintenance

• Definition:
• short periodic work carried out pre-dominantly
on-line
• ex: inspections, lubrication, adjustments
• Goal:
• reduce downtime and breakdowns
• extend the life of the equipment or system
• Properties:
• planned & prepared
Maintenance types: routine maintenance

• Definition:
• comparing the trend of measured physical
parameters against known engineering limits
• Goal:
• detecting potential and hidden failures (see next
slide)
• Properties:
• planned
• condition based
Maintenance types: predictive maintenance

• Types of failures
• functional failure: the inability to meet the
specified performance standard
• potential failure: a physical condition which
indicates that the failure process has started
(metal particles in oil)
• hidden failure: failure is not apparent until the
function is attempted

- Possible actions at P
- prevent functional failure
- avoid consequences of the failure
Operating
Condition
Time
100%
Failure starts
to occur
.Failure can be
detected
.
.Failure has
occured
P
F
The majority of failures do not occur instantaneously but develop over
a period of time (P-F Curve)

• Diagnostic devices:
• Vibration analysis
• Lubrication analysis
• Infrared thermography
• Ultrasonic testing
• Shock pulse methods
• Oil analysis
• Coolant analysis
• Wear particle analysis

Guide
Maintenance planning and scheduling

2.4. Maintenance planning and scheduling
• Work request
• formal request to have work done.
• Can be filled out by a production or maintenance
employee
• Work order
• Written authorization to proceed with a repair or
other activity to preserve an asset function
Definitions

• Work planning
• assigning work orders to a time period
• plan resources
• Work scheduling
• arranging the sequence of the work orders
• considerations
• priority
• availability of craftsperson
• availability of material and equipment
• desires of the operating personnel

• Work identification
• by operation or maintenance personnel
• Work order creation
• work order number
• date
• originator
• asset identification
• short description
• priority
• approved by
Workflow

• Work preparation
• accounting code
• job description (sequence of events)
• crafts required
• material required
• tools required
• safety and environment considerations
• estimated hours

• Work execution
• Progress tracking
• Work analysis
• Recording information
• nature of occurrence of the failure
• nature of the failure
• nature of the repair
• total downtime, labor-hours and spare parts

• Work preparations are important
• facilitate estimation
• assure that the job will be done in the most
efficient manner
• contribute to training by indicating the
methodology of the job
• the preparation can be used the next time the job
has to be executed
Work preparation

• A priority system is established to ensure
that the most needed work orders are
scheduled first
• Example of priorities
• 0: emergency or safety work
• 1: work to start within 24 hours
• 2: work to start within 1 week
• 3: work to start within 1 month
• 4: turnaround or overhaul
Priority system

• What is Backlog:
• all work available to be done. Backlog work has
been approved and prepared
• The backlog must be used as a tool to make
decisions
• informs management about future needs for
maintenance (contracting, more or less
personnel)
• must be effectively managed so that it does not
grow to an unmanageable size
Backlog management

Guide
Resource management

2.5. Resource management
• Resources
• people
• spare parts
• tools
• Resource management
• matching the resources to the workload

• Utilization of people can be improved by
• managing the size of the backlog
• contracting
• shift from unplanned to planned work
• smoothing the workload
People

• The optimal balance between the cost of
holding and the cost of stockout must be
achieved
• Classification of spare parts
• Function
• Usage rate
• fast moving
• slow moving
Spare Parts

• Spare parts management
• the right parts in the right place at the right time
in the right quantity
• create an equipment history analysis
• identify dormant or excess stock items
• establishment of workable stock levels, controlled
by supply lead-time and usage

• Tools are not consumable
• Tools must be
• monitored
• maintained
• replaced on time
Tools

Guide
Performance measurement

2.6. Performance measurement
• Maintenance is often organized and
performed without proper measures to
determine its impact on the business’s
success
• You need
• consistent and reliable data
• high quality analysis
• clear presentation of the information
You can’t manage what you don’t measure

2.6. Performance measurements
• Actual budget versus forecast
• Maintenance costs
• overhead, labor, contractors, spare parts
• as a % of sales
• per unit produced
• Safety and environmental performance
General

• Ratio of contractors to company employees
• Ratio of production to maintenance
employees
• Maintenance employees per supervisor
• Maintenance employees per planner
• % overtime hours
• % absenteeism
Organization

• Inventory turnover
• Inventory accuracy level
• Inventory service level
• % downtime due to stockouts
• Materials versus labor ratio
• Dormant stock items
• Excess stock items
Spare parts

• Work order lead time
• Workload (backlog) level
• by craft
• by priority
• by type
• Man hours per work order
• Daily schedule completion
• % emergency, corrective, preventive and
predictive maintenance of total activity
Work order management

• Overall Equipment Effectiveness
• Reliability
• Availability
• Maintainability
• Mean time between Failure
• Costs for each asset center
• Return on investment
Equipment

Guide
3. CMMS

3. CMMS
3.1. Definition
CMMS
=
Computerized Maintenance Management
System
(computer replaces manual systems)

3. CMMS
3.2. Basic modules
• Asset register
• documentation
• equipment data management
• multi-level hierarchical filing system
• Work order management
• History file
• required for feedback
• maintenance of work preparations
• reporting
• Spare parts inventory control

3. CMMS
3.3. Optional modules
• Budget analysis
• Invoice / ordering control
• Condition Based Maintenance Manager
• Failure analysis

3. CMMS
3.4. Trends
• Internet-enabled
• bringing information and training to the shop
floor
• transferring analysis data to equipment suppliers
• online equipment monitoring
• purchasing of spare parts (e-procurement)
• software vendors will host CMMS on their own
servers (Application Service Providers)

3. CMMS
3.4. Trends (2)
• Data Input:
• Use of handheld computers by technicians
• Interfacing with bar code terminals
• Integration of Supply Chain Software and
CMMS

3. CMMS
3.5. What do you really need?
• Most companies don’t have the resources and the
commitment to implement the system
• If you don’t have CMMS in your company, you can
get a good feeling of CMMS by using the
Computerized Work Order Management System of
our company.
• Look at http://www.managementsupport.com/cmms.
htm
Poor utilization of the available functions
(5 to 10 %) is quite common

4. TPM
• TPM is a company-wide team-based effort to
build quality into equipment and to improve
overall equipment effectiveness (OEE)
• TPM principles, components, implementation
and benefits are handled in detail in The
Total Productive Maintenance Guide
http://www.managementsupport.com/tpm.htm

5. RCM versus TPM
RCM is strong in determining what
maintenance to do, while TPM is all
about improving rather than merely
maintaining your processes

Guide
6. Good Maintenance Management

6. Good maintenance management
• Maintenance is recognized by management
as an integrated, essential part of production
• Continuous improvement programs are in
place
• performance is evaluated
• reasons for downtime are analyzed
• corrective actions are taken
• progress is measured
Principles

• There is a commitment to improve the ratio
of planned versus unplanned work
• There is an emphasis on training
• Operators are involved in the maintenance of
their equipment

• Equipment
• downtime reduction
• smoother running
• reduced waste
• higher return on investment
• increased equipment life
• repair history available
Benefits

• People
• more efficient operation
• balance of workloads
• reduced overtime
• increased cooperation between production and
maintenance departments
• Spare parts
• lower inventory levels
• lower usage

The end
Please feel free to give any
comments to
imants@skynet.be

Mm

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