Maintenance Dictionary
Maintenance, the act of maintaining, the state of being maintained, care or upkeep of machinery, the process of maintaining or preserving someone or something, the process of keeping something in good condition, the work of keeping something in proper condition. Brows our Maintenance Dictionary for other definitions within the maintenance field.
Actuarial analysis
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Statistical calculation, especially of life expectancy
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Add-on work
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Work added to a maintenance schedule after the agreed upon cut-off
time for the schedule.
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Action results Indicator
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Key Performance Indicators used for measuring results of actions that
indirectly or directly impacts the financial performance of the company.
Examples
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Apprentice
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An employee in a certified training program to become a craftsperson.
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Asset
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An accounting term for any physical thing owned by a plant, such as
buildings, equipment, desks, software, computers etc.
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Asset number
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A number that follows a particular asset in a plant, should be used
for accounting purposes. Note an asset number is different from an equipment
location number. An equipment location number stays in the same location,
where an asset number may move location.
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Asset Replacement Value
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The current accounting value of all combined physical assets in a
plant.
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Assessment - reliability
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A study comparing the Current best Practices (CBP) with actual
performance. The study assesses the effectiveness of processes in place.
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Autonomous Maintenance
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Maintenance processes driven by hourly workforce without management
support or intervention.
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Autonomous Training
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Training that is incorporated into the day-to-day work processes. The
training is based on experiences and findings from the daily work and is then
communicated on a regular basis.
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Availability
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Percentage of total hours (8760/year) or scheduled operating time a
system is available for production.
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Backlog
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Volume of all requested maintenance work, yet not completed
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Backlog - approved
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The approved backlog is all maintenance work that is not completed,
but approved for execution.
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Benchmarking
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The continuous, systematic search for, and implementation of, better
practices that lead to improved performance
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Bill of Materials (BOM)
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A document of all parts for an asset.
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Break down
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When a piece of equipment ceases to function (according to predetermined
parameters)
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Break-In job
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Work that changes a set schedule after an agreed upon cut-off time.
Break in job are either:
1. break-downs
2. emotional add-on
work
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Capital work
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Work done for improvements or betterments which will increase the
value of assets.
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Capital Spares
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Spare parts that are depreciated (not expensed) in accounting books.
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Charge rate
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The amount per hour a resource cost for the company. Wages plus
benefits. Benefits are usually around 35% of the salary in The USA, 50-60% in
Europe. Benefits include insurances, vacations, and other time off.
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Component
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A generic technical part. Many components make up equipment. Hierarchy
is that parts make components, makes equipment, makes systems.
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Computerized Maintenance Management System (CMMS)
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A computer program or interfacing programs used to manage the
maintenance function in a plant.
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Condition Based Maintenance (CBM)
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Maintenance actions taken as a result of investigated condition of
parts or components. The condition is measured or evaluated during programmed
inspections of parts and components.
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Condition Monitoring
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All work performed in order to find failures early.
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Consequence Of Break-Down (COB)
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The “cost”, not always measured in money, of a break down of
equipment. COB is prioritized as follows:
1. Environmental
damage or safety hazard
2. Production loss
3. High Cost
(equipment life)
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Continuous Improvement
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Continuous improvement of existing practices resulting in improved
performance.
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Corrective Maintenance
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All maintenance performed to correct a break down or failure.
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Cost Effective
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When the monetary benefit exceeds the cost of implementing an
improvement.
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Crafts people
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People with professional skills in mechanical, electrical or
instrumentation maintenance. Many plants require skills in several of the
skills mentioned.
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Criticality
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The criticality of a component, equipment, or system based on the
consequence of Break-Down.
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Current Best Practice (CBP)
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. The future might reveal a better way of doing
something and thus change the CBP. A CBP is equal to an element, which is the
lowest level of detail in a Key Process.
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Cut-off time
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Time when a schedule closes.
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Defect 1
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Damage on final product which forces the plant to scrap product, or
sell product for lower price.
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Defect 2
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Can also mean a failure in a part or component.
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Downtime
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Time when a system is not producing product. Downtime includes
scheduled and unscheduled downtime.
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Downtime scheduled
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When a system is down, and the downtime was documented as scheduled
before cut-off time.
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Downtime unscheduled
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When a system is down, and the downtime was NOT documented as
scheduled before cut-off time.
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Emergency Work
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Emergency work is a synonym to break-in work.
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Equipment
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An asset that performs a function e.g. a motor coupling pump, pumps
water from pint A to point B.
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Equipment History
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Documentation for all events such as repairs, modification, and
preventive maintenance performed for a specific equipment.
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Equipment location
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A physical location in the plant for a piece of equipment.
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Equipment Location number
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A unique number assigned to an equipment location.
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Equipment reliability
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Time, speed, and quality performance as it relates to equipment. ROM philosophy, equipment reliability is the result of maintenance
work.
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Essential Care
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A
compilation of processes that will prevent failures from occurring. For
example lubrication, alignment, balancing, cleaning, and operating
procedures, adjustments and installation procedures. Essential Care prevents
failures (prolong life of equipment).
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Estimated Replacement Value
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Estimated present value of assets.
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Failure
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When equipment condition reaches an unacceptable level. Example: A
motor may run, but the temperature is 250 °F (unacceptable)
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Failure Code
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A classification of a failure.
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Failure Developing Period
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The time lapsed between a failure and the break down.
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Failure Mode
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Any event that may cause a failure.
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Failure Mode and Effects Analysis (FMEA)
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Analysis tool to Identify Failure modes, assign priorities to each
failure mode based on cost and occurrences.
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Failure Rate
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An average of how often a component, equipment or system fails in a
given time period.
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Feedback
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In maintenance. Most commonly used when referring to written
description of the work completed on a work order.
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Fixed Time Maintenance (FTM)
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This tactic provides for scheduled overhauls or replacements of
components often based on recommendation from the equipment vendor, general
plant experience with similar components or analysis of the maintenance
history of an individual piece of equipment and its components. Note: Only 10-15% of all component types
have a predictable failure rate. Cost effective use of FTM is therefore
limited.
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Frequency of Inspection
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The time period between a repetitive inspection. The inspection
frequency should be based on the failure developing period. Note: A rule of thumb is that the
inspection frequency should be: Failure Developing Period/ 2.
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Gantt Chart
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A bar chart (histogram) of scheduled tasks. Microsoft Project, and
timeline are examples of software using Gantt charts.
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Gap Analysis
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A rated comparison of Current Best Practices and actual performance.
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Goal
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Measurable results you wish to accomplish at a projected point in
time.
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Iatrogenic
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In maintenance. Failures induced by own employees. Note: Iatros means
physician in Greek, and -genic, meaning induced by, is derived from the
International Scientific Vocabulary. Combined, of course, they become
iatrogenic, meaning physician-induced. Iatrogenic disease is obviously, then,
disease which is caused by a physician.
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Infant mortality
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Component failures occurring during early life of component (1-12
months).
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Inspection
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Any activity performed to find a failure or break-down.
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Inspection List
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The printed list of an inspection route.
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Inspection Route
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Documented instructions for condition monitoring tasks, sorted in an
effective walking path through an area.
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Inspector
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The person doing the inspection routes. Note: This could be an
operator, crafts person, supervisor, engineer or a manager.
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Key
performance Indicator (KPI)
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A
measurement of process performance.
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Key
Process
|
The key
processes are:
1.Leadership and organization 2.Preventive Maintenance 3.Planning and Scheduling 4.Root Cause Problem Elimination 5.Technical Database 6.Materials Management 7.Skills Development maintenance 8.Safety – Maintenance 9.Engineering |
Life
Cycle Cost (LCC)
|
Total
cost for acquiring, owning and disposing physical assets. Includes direct
operational and maintenance costs and indirect costs for lost production when
system fails.
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Life
Cycle Profit (LCP)
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The
present value of all revenue the equipment has generated less the LCC.
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Log
Book
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Usually
refers to operations log for problems found during shift.
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Logic
Tree
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A
charting method for why-why analysis.
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Management
of Change (MOC)
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A
process used to track and manage any physical or specification changes made
to process related equipment in a plant.
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Maintainability
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The
ease to maintain equipment.
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Maintenance
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Maintenance
consists of corrective maintenance, preventive maintenance, and continuous
improvement.
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Maintenance
Engineering
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Maintenance
Engineers work on design specifications of minor modifications, preventive
maintenance documentation, problem identification and elimination,
maintenance training, and maintenance technical database.
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Maintenance
Management
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Maintenance
management is the collective term for describing the management process of
leadership and organization, planning and scheduling, preventive maintenance,
condition monitoring, execution of maintenance repairs, recording, root cause
failure analysis, spare parts management, and management of technical data
supporting the processes above.
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Maintenance
Opportunity
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See
maintenance window
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Maintenance
Planning
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See
definition for “Planning”
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Maintenance
prevention
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All
actions performed to prevent failures. Lubrication, alignment, balancing,
installation and equipment design, operating procedures, detailed cleaning,
adjustments, fixed time replacements, and filtration. Note: Maintenance
prevention and condition monitoring are the two components of preventive
maintenance
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Maintenance
Window
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Defined
time slots when maintenance can be performed on equipment without disturbing
production.
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Mean
Down Time (MDT)
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Average
time equipment is down (for any reason).
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Mean
Time Between Failures (MTBF)
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Total
calendar operating time divided by number of failures.
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Mean
Time To Repair (MTTR)
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Average
Repair time for component.
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Mean
Wait Time (MWT)
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All
time during downtime that isn’t repair time. MDT=MWT + MTTR
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Mission
Statement
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Summarizes
how to achieve a vision.
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Model
Work Order
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See
Standard Job Plan
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Non
Destructive testing (NDT)
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Any
material testing that doesn’t destroy material. During the testing process.
Note: Usually we think of Ultrasonic Thickness Testing. Also included in NDT
is usually dye-penetrant testing, x-ray testing, and electrical resistance
testing. Vibration, thermography, look, listen, feel, smell, winding test etc
are not included since they are testing components, and equipment, not
material.
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Non-Scheduled
work
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See
unscheduled work
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Objective Condition
Monitoring
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Preferred
over subjective condition. Objective methods are for example vibration
analysis, ultrasonics, and temperature-, pressure-, voltage- and ampere
readings. Subjectiveinspections are look, listen, feel and smell
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Off-line
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Downtime
for a component or system without affecting production. Note: If production
is down it’s considered an outage, or shutdown/ Turnaround.
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Oil
Analysis
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Testing
of oil in order to find failures early
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Operate
To Break-Down (OTB)
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A
maintenance strategy which operates equipment until break-down. A maintenance
strategy which sometimes can be the most cost effective. Note: OTB is used
when the consequence of failure is small enough that the benefit of
preventing or finding failure early is more costly. OTB will be the fact for
failures that occurs randomly and have no failure developing period.
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Outage
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A
shutdown/ turnaround that affects the whole plant for more than 16 hours.
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Overall
Production Efficiency (OPE)
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The
product of Quality [%] * Speed [%] * Uptime [%] for a production line.
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Overall
Reliability
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See
Production Reliability
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Parts
|
See
spare parts
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Planned
Job
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A
planned job includes:
·
The
person planning the job verifies the scope of the job.
·
Lifting
Equipment, tools, parts, material and personal. Equipment needed to do the
jobs are identified and allocated.
·
Skills
needed are identified?
·
A
description of job steps is documented.
·
Lock
out tag out and other safety requirements are identified.
·
Necessary
technical documentation is available.
·
Crafts
people are part of the planning process.
·
Estimated
job duration by skills and the number of people needed for the job.
·
Required
permits available.
·
The
cost of each job is estimated.
·
Define
physical and environmental constraints.
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Planning
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The
process of determining the resources, methods, and processes needed to
perform maintenance work efficiently and effectively. Note: Planning is
different from scheduling. Planning short definition is to decide what, how
and time duration.
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Predictive
Maintenance
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A
synonym to condition monitoring. There are many other
condition monitoring tools besides vibration analysis.
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Preventive
Maintenance
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Essential
care and fixed time maintenance together. Both essential care and fixed time
maintenance PREVENTS (both prevent) FAILURES, while Conditions Monitoring
only DETECTS FAILURES EARLY.
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Priority
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The
assigned importance of a maintenance job.
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Priority
Code
|
The
importance of a maintenance job is defined by a priority code. A priority
code represents a deadline for when the maintenance job has to be completed.
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Priority
Guideline
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Agreed
upon guidelines for assigning a priority to maintenance work.
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Proactive
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Actions
that are planned, scheduled and executed before a break-down occurs. Includes
maintenance prevention activities.
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Problem
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Any
issue that can be improved cost effectively.
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Process
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A work
system that is documented, executed, and measured.
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Process
reliability
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Time,
speed, and quality performance as it relates to manufacturing process.
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Production
reliability
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The
product of process and equipment reliability.
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Purchase
Order (PO)
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The
document sent to a supplier to order parts, services, material, or machines.
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Reliability
Centered Maintenance (RCM)
|
A
maintenance philosophy which is heavily designed by engineers supported by
sound theoretical practices. Note: No known plant have been able to implement
a full RCM strategy. It is often a very complicated theory for simple common
sense actions. RCM has a given place in the specification phase when
designing new equipment.
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Reliability
- Equipment
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The
product of Quality [%] * Speed [%] * Uptime [%] as it relates to equipment.
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Reliability
- Process
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The
product of Quality [%] * Speed [%] * Uptime [%] as it relates to the process
(operation of equipment).
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Reliability
- production
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The
product of process reliability and equipment reliability. Measured by Quality
[%] * Speed [%] * Uptime [%]
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Repair
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Any
activity intended to bring a component, equipment, or system back to a
specific condition.
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Repetitive
work
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Type of
work that are done often in the plant. Repetitive work should have standard
job plans.
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Results
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Financial
outcome of an action, or several actions.
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Results
Indicators
|
Global
Key Performance Indicators measuring results directly impacting the financial
performance of a plant.
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Rework
|
All
repairs that have to be done again due to a poor repair the first time. Note:A combination of poor planning
and scheduling. Usually due to lack of skills, material problem, missing
spare parts, or not enough time assigned to do a precision job before starting
equipment again.
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Root
Cause Failure Analysis (RCFA)
|
A
systematic way to collect select, analyze, and solve failures
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Root
Cause Problem Elimination (RCPE)
|
A
systematic way to collect select, analyze, solve and eliminate a problem.
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Safety
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The
result of all actions executed to prevent personal injuries.
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Service
Factor
|
A key
performance indicator for the storeroom measuring the % of times the correct
quantity of the correct part is received when requested. Note: If the service
factor falls below 95% maintenance people begin to lose confidence in the
store room’s ability to supply the correct material & parts when needed.
Usually result in growth of “unofficial personal stores” at frontline level.
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Scheduled
job
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A job
put on the schedule before the cut-off time. Specific people, start time and
end time is documented.
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Scheduling
|
The
process of determining what jobs gets worked on, when, and by whom based on
the priority and resource/equipment availability. Note: that this process
should take place before the job is executed. See definition for ”break-in
job”. Scheduling short definition is when and who.
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Scheduling
compliance
|
A KPI
measuring: The sum of Add-on jobs and jobs, on the schedule, not completed
OVER the jobs on the schedule before cut-off time.
|
Shock
Pulse measurement (SPM)
|
A
condition Monitoring Tool measuring the shock pulse in rotating equipment.
Note: Shock pulse is the pressure wave generated through materials when two
materials hit each other. A vibration will wave will be generated by the
Shock pulse
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Shutdown
|
Scheduled
or unscheduled downtime for a system or plant area.
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Source
|
An
event that triggers a failure.
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Spare
Parts
|
All
machine parts, materials and supplies that may be required to repair an asset
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Standard
Job Plans
|
A
documented plan for a type of job that can be used repetitively. See planning
for definition of “plan”
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Subjective
maintenance
|
Look,
listen, feel and smell
|
Terotechnology
|
Maintenance
management and technology. A term often used by universities in the UK.
|
Total
Productive Maintenance (TPM)
|
A
maintenance philosophy. TPM is usually profiled for the strong operator
involvement in equipment care.
|
Trades
person
|
See
craftsperson
|
Tribology
|
The
science and technology of interacting surfaces in relative motion, including
the study of lubrication, friction and wear.
|
Tribological
wear
|
Wear
that occurs as a result of relative motion at the surface.
|
Turnaround
|
See
shutdown. Term usually used in steel, alumina, and mining industry.
|
Unplanned
Maintenance work
|
A
maintenance job where necessary planned activities are incomplete before job
is scheduled. Planning should always be done before scheduling.
|
Unscheduled
Maintenance Work
|
Work
added to the schedule after the cut-off time.
|
Uptime
|
Opposite
to Downtime. Time when a component, equipment or system is producing product. Note: The component, equipment or
system may produce defect product or at a slower speed than usual.
|
Vibration
Analysis
|
A
condition Monitoring tool measuring the vibration in equipment.
|
Vision
Statement
|
Summarizes
what an organization (or individual) want to achieve in the future. A vision
must be supported by a mission statement and a goal.
|
Why-why
analysis
|
A
problem solving method which forces the problem solver to break down and
analyze different possible causes as to why a problem occurred.
|
Work
Load
|
All
work in the approved backlog. Can be measured as follows: The sum of
estimated hours in the approved backlog divided by the craftspeople available
for a particular area, or supervisor. Best is to trend this number over time.
A well managed maintenance area has about 2-4 weeks of workload.
|
Work
Order
|
An
approved work request.
|
Work
Request
|
A
request to do maintenance work.
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