Reliability Centered Maintenance (RCM) Scorecard

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RCM 2005 Workshop

Consensus as of 9 March 2005 

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Reliability Centered Maintenance (RCM) Scorecard

RCM 2005 Workshop

Consensus as of 9 March 2005

Introduction

This Reliability Centered Maintenance (RCM) Scorecard provides a “menu” from which a selection of metrics, measures or Key Performance Indicators (KPI’s) may be selected for evaluation at various periods before and during an RCM Project. It addresses four distinct aspects that should be considered for any RCM project, namely:

·         Decision whether or not to initiate the project

·         Analysis Phase

·         Implementation Phase

·         Benefits Phase

The relationship between metrics of the items listed above is illustrated in the following diagram (Figure 1).

Time relationships between the items are illustrated in the following chart (Figure 2).

Readiness of an organization to initiate an RCM Project with a reasonable expectation of success is different from the decision to initiate one. Determination of readiness for success of an RCM Project is (to be) addressed separately, since the factors are largely subjective and do not yield to an approach involving evaluation of metrics.

Objectives of a Reliability Centered Maintenance (RCM) Scorecard are to:

·         Provide prospective and actual RCM users, participants and other interested parties with a tool to help decision making on whether or not to initiate an RCM Project and  (given the decision to proceed) determine progress in or demonstrate how successful  it is while in progress and was after completion. RCM Scorecard metrics, measures or Key Performance Indicators (KPI’s)  use data collected:

Ø      When considering whether or not to conduct an RCM analysis on an asset

Ø      Prior to performing an analysis, (prior to the RCM Analysis Phase) as a baseline

Ø      During the RCM project Analysis Phase

Ø      During and/or after RCM analysis as resulting action items are implemented (RCM Project Implementation Phase)

Ø      From the point after implementation begins and throughout defined period(s) when benefits are realized. (RCM Project Benefits Phase)

·         Provide cognizant managers, supervisors and/or “champions” with a tool to help justify an RCM Project and to measure progress on a given asset or set of systems during analysis and implementation phases. In addition, it provides a basis  for measuring the benefits derived from the overall effort.

·         Provide a basis for comparison of differing approaches to RCM methodology

RCM Scorecard terminology was developed using the following sources:

·         Reliability Centered Maintenance by F. Stanley Nowlan and Howard F. Heap

·         RCM: Gateway to World Class Maintenance by A. M. Smith and G. Hinchcliffe

·         RCM Overview Workshop at 2004 SMRP Conference

·         SMRP Best Practice Metrics document (Draft)

·         Overall Equipment Performance by Robert C. Hanson

·         Glossary of Reliability and Maintenance Terms by Ten McKenna and Ray Oliverson

·         Progressive review and comment by RCM-experienced users and practitioners during the period from May 2004 to January 2005

·         Consensus developed during a workshop attended by over 100 persons conducted 9 March 2005, the day before the RCM Managers Forum Conference in Clearwater Beach, Florida

Definitions for terms and abbreviations used in the RCM Scorecard can be found in the Glossary, starting on page 17 of this document.

To avoid confusion between terms and phrases used in other contexts within the fields of Maintenance and Reliability (M & R) the following notes are provided.

Note 1: Corrective maintenance  in the context of the metrics included in the RCM Scorecard refers to unplanned (unexpected or reactive) maintenance to restore the functional capabilities of an asset. It includes repeat maintenance required because initial attempt(s) at repair were not successful for any reason. It does not include maintenance that results from preventive or predictive (PM and on condition or condition directed., or PdM) tasks, which can be anticipated, pre-planned and scheduled. Corrective maintenance is a subset of Emergency/Demand Maintenance.

Note 2: Corrective maintenance in the Total Productive Maintenance (TPM) sense refers to actions taken to modify the asset to improve its performance. The labor hours and material costs for these improvements (as well as those that improve asset maintainability) should be categorized separately and not be included as part of any metric associated with the RCM Scorecard, unless the recommendation of a design improvement results from RCM analysis on an asset.

Note 3: RCM Scorecard maintenance labor hour expenditures do not include those labor hours expended by operators who perform PM and PdM tasks as part of their normal duties, unless the operator position has been created and the number of operating staff personnel was increased exclusively for the purpose of maintenance.

Note 4: In an RCM-based program the analysis process is focused first at the level of functional failures, then at the level of failure modes (ways functional failures occur and their causes) and the tasks that are chosen to mitigate or prevent the failure mode or cause. For purposes of the RCM Scorecard, in order to give all task-related metrics a common base, it is important that each task be related to a failure mode, not to a component. This may be difficult to do for old, pre-RCM program tasks and indeed there may be tasks for which no related failure mode is evident, providing one basis (among several) for consideration of whether or not it should be retained in the RCM-based program.

Note 5: All tasks for an RCM-based program must be applicable and effective

–        An applicable task will prevent or mitigate the failure, detect onset of failure or detect a hidden failure. It’ll work to assure or restore reliability margin to a tolerable level.

–        An effective task is the most cost-effective option among the technically feasible, applicable candidate tasks.

Baseline “Current” or “Old” M & R Program Metrics

 and Traditional  KPI’s for Decision on RCM Analysis  

Metrics listed in the tables in this section and the Benefits Phase section (beginning on page 14) may not all be available to users of the RCM Scorecard. However, they are provided for possible use as follows:

·         When considering whether or not to conduct RCM analysis on an asset.

·         If the decision is made to proceed with RCM analysis on an asset, many of the same metrics selected may be used as a baseline set for comparison with the new, RCM based program results achieved during the Benefits Phase.

The decision of whether or not to conduct RCM analysis on an asset requires that many factors be considered. Among these are:

·         Importance of the asset to the activity in which it is engaged

·         Hazards involved in operating and  maintaining the asset both to employees and people in surrounding areas and communities

·         Problems encountered in operating the asset, such as its:

Ø      Availability, uptime and downtime relative to demand for most economical operation of an asset such as a production line, transport vehicle or whole plant

Ø      Quality of product or service produced, Scrap Rate

Ø      Cost of operation of an asset as expressed in efficiency (e.g., Heat Rate for a electricity generating plant or cost of energy for a production plant, vehicle or service facility)

Ø      Throughput and Yield or Capacity Factor relative to that needed to meet demand with current assets

Ø      Total Cost of Maintenance or Total Cost of Operations, Cost of Quality or other economic factor of production when it is affected by the maintenance and reliability program

Ø      Stress on maintenance and operating personnel under the current program

Ø      Overall profit margin for the product or service provided with the asset

Other, more direct measures related to the type of tasks employed in maintenance have been found to characterize the most successful organizations.  KPI’s related to tasks may also be useful in reaching a decision on whether or not to engage in RCM analysis for an asset. In addition, if the decision is taken to conduct an RCM analysis, task metrics may be used for comparison of the pre and post RCM maintenance programs. In general, the following statements apply to types of tasks employed in RCM Based and Pre-RCM programs:

·         Non-intrusive maintenance tasks are preferred because there is less likelihood of functional failure caused by human error after  conducting them than there is for intrusive tasks.

·         The more non-intrusive maintenance tasks, relative to intrusive tasks, the more effective a program is in avoiding unscheduled downtime and lost production.

·         The greater the percentage of on condition or condition directed tasks, the lower the overall cost of maintenance due to the fact that no actions other than monitoring are performed until condition directs a repair.

·         Old (Pre RCM) programs, developed under methodologies that predate RCM generally do not recognize many “Hidden Failures.” RCM based programs, which emphasize “Functional Failures” having safety or operational impact, will normally account for all of the important Hidden Failure possibilities.

·         Old,  current or existing (pre-RCM) programs seldom document Run-to-Failure (RTF) or other decisions, whereas RCM-based programs allow for RTF or other decisions (e.g., for statutory or regulatory reasons) under certain conditions. Under RCM methodology, RTF may also be a valid choice when all other task options are more costly and there is no safety and little or no operational consideration involved in allowing a failure to occur and correcting the problem (restoring the function) afterwards.

·         In some cases “old” re-RCM programs specify tasks for which there is no justification, when an attempt is made to align failure modes identified by RCM analysis with “old” program requirements or tasks. This gives rise to the possibility of “old” program tasks not being continued under the new RCM-based program. These non-applicable tasks are cancelled, removed from maintenance schedules and not replaced by other tasks.

  A set of metrics may be used in whole or in part to aid the decision making process and to support obtaining the assets needed to do so. Metrics proposed for these purposes are listed in the table, entitled Table 1 - “Current” or “Old” Maintenance and Reliability (M & R) Program (Baseline) Metrics” on the following page. These metrics, for use in making the decision whether or not to conduct RCM analysis on an asset, are then used for baseline comparison with the new M & R program after RCM implementation has begun to take effect as illustrated in Figure 1 on Page 2.

It is stressed that only a few of the metrics in the following tables in this section and the Benefits Phase Section may be meaningful to a given organization, and that those presented are not the only ones available. For example, in M & R Programs suspected of having too many or too burdensome maintenance requirements, Maintenance Backlog is often very high and compliance with the current PM program is very low. The metric that may be most useful in this case is PM Compliance. In the consensus workshop it was suggested, without any objection, that as few as 6 or 8 metrics may be all that are needed to make the case for an RCM Project and to determine benefits derived from it.

Where applicable, the time period for the collection of some of the metrics or KPI’s in the tables that follow will vary from organization to organization and differ between industries and various types of facilities, activities, services or missions. In some applications metrics may be affected by seasonal factors. For these reasons, no specific time frame is provided other than to recommend that those timelines selected provide a representative baseline for later comparison, should the decision be made to go forward with an RCM Project. In some cases a graphical or tabular representation of the metric or KPI over time may be more meaningful than a single number. It is important, however to ensure that the metrics collected be for the same asset or combination of assets before and after implementation (during the Benefits Phase of an RCM Project).

Table 1 - “Current” or “Old” M & R Program (Baseline) Metrics

Note 1: Where a metric involves labor hours, it may be useful to break out subsets by trade category (e.g., Electrical, Mechanical, etc., )

Note 2: It has been useful in some instances to distinguish between labor hours and replacement parts cost for repair of the primary asset to be subjected to RCM analysis and conversion to a new program and labor hours and replacement parts cost for or collateral damage in secondary assets beyond the primary.

In addition to the metrics for an asset listed in Table 1, some more “traditional metrics” may be used to decide whether or not to conduct an RCM analysis on an asset. The table on the following page, entitled Table 2 - “Traditional (Baseline) KPI’s  for Decision on RCM Analysis” lists the types of measures typically being tracked already in many facilities. However, a special effort may be required to obtain metric values focused on the asset or assets of concern.

Table 2 - Traditional (Baseline) KPI’s  for Decision on RCM Analysis

RCM Project Analysis Phase Metrics

The tables for this phase on an RCM Project list sets of metrics that are useful in determining the nature of maintenance tasks in the new program to be put in place (or now in place) compared to the old program for a given asset selected as a candidate for RCM analysis.  During the analysis itself, progress may be reported in terms of total tasks of each type that have been determined to be needed at the points in the analysis process when the reports are made.

An example of a table of metrics comparing new with old programs in terms of tasks and run-to-failure decisions and entitled Table 3 - “Tasks and Decisions Profile” is shown below.

Table 3 - Tasks and Decisions Profile

To these are added two additional metrics described in the table below that will be useful when implementation begins. These metrics in the table below entitled Table 4 - “RCM Based Decision Metrics,” like those above, should be readily available from the RCM analysis report or analysis software package.

Table 4 - RCM Based Decision Metrics

The numbers for each category of action item (Task, RTF or Other Decision, Design Modification, Operational Procedure (change or addition) Recommendations) to be implemented under the new program should be used in RCM-based program implementation progress reports. See page 12 for Implementation Phase metrics.

The  set of metrics describing Pre and Post RCM Programs in terms of tasks and decisions is presented in the following table, entitled Table 5 - “Task Similarity and Decision Profile Metrics.” Some of the metrics described in this table should be used as a target against which progress towards conversion to an RCM based program is reported. These reports should keep track of how many action items in each category have actually been acted upon during the Implementation Phase. For purposes of the Analysis Phase, this is a one-time set of metrics to provide an understanding of the nature of changes that must be made to implement the new (RCM Based) program.

Table 5 - Task Similarity and Decision Profile Metrics

# Percentage of total decisions should add up to ~100

Note: Total changes = Sum of all Modified Old Tasks + New RCM tasks +RTF or Other Decisions + Old program Tasks to be Cancelled + RCM Program Tasks that are different than Old Program Tasks for the same failure mode.

Another set of data, Table 6 - “RCM Project Commitment Metrics,” may be useful to sustain momentum during early phases of an RCM project and to gain acceptance of the new program from personnel unfamiliar with RCM and its benefits.

Table 6 - RCM Project Commitment Metrics

Note: Labor hours may be broken down further, for example for RCM Project Manager, Facilitator(s), and Analysis Team Members

A final set of metrics for the Analysis Phase explains in RCM terms (Functions, Functional Failures, Failure Modes, Hidden Failures, etc.,) the results of the analysis. The set in the table below, entitled Table 7 - “Asset Analysis Profile,” is usually reported at the end of the RCM Project Analysis Phase and only one time. However, these may also be reported periodically during the Analysis Phase to define progress, if that phase is drawn out for an extended period.

The final Asset Analysis Profile for the complete analysis of an asset may be used for comparing efforts on future RCM projects and for orientation and training of personnel new to RCM Methodology. In the latter instance the numbers are useful for giving these personnel an idea of the magnitude of the effort involved in an RCM analysis project.

Table 7 - Asset Analysis Profile

RCM Project Implementation Phase Metrics

RCM based implementation metrics provide measures that signify progress towards implementing an RCM based maintenance program. Using numbers identified during the Analysis Phase as a basis, the metrics concentrate on the number and percentage of each category (new task, modified task, cancellation of specified old program tasks, design modifications, operational procedure changes, etc., that have actually been implemented.

 Implementation will (or should) usually begin during the Analysis Phase of an RCM project, and may provide information for improvement of the analysis. Implementation involves many activities, such as:

·         Identification of resources (money, time, manpower)

·         Coordination with governing authorities or other parties affected

·         Procedure writing, walk down and approval

·         Procurement of special tools, parts and consumables needed to carry out the procedures mandated under the new program

·         Training or at least orientation on the new procedures for those who are to perform them

·         Planning and scheduling of new RCM based procedures

·         Actual execution the first time on the asset that was subject of the RCM Project

Action items should be tracked and periodically reported during the Implementation Phase. The table below, entitled Table 8 - “RCM Based Program Implementation Metrics” provides proposed measures that signify progress towards implementation .

Table 8 - RCM-Based Program Implementation Metrics

All of the above implementation action items require labor hours. To the metrics above may be added the set on the following page, entitled Table 9 - “RCM Based Program Implementation Labor Hours Metrics” that deals with the effort expended to date (of report) to implement an RCM based program for a given asset or set of assets. The metrics report labor hours expended to date compared to the last report.

Table 9 - RCM Based Program Implementation Labor Hours Metrics

RCM Project Benefits Phase  Metrics

Benefits Phase metrics use as a starting point and constant reference the same metrics tracked for the same asset or set of assets for the representative periods selected  prior to implementation of the new RCM based program. (See Table 1 - “Current” or “Old” M & R Program (Baseline)  Metrics on pages 7). A useful presentation may consist of a set of graphs with the metric(s) plotted against time and the point where implementation began clear marked. Periods selected should be “representative” of what are considered to be the “normal” operating profile for the asset being evaluated. Trends will then be evident and referenced to a definite point in operating time when results of the RCM project should begin to emerge. These metrics, although entitled Table 10 - “RCM Based Maintenance (M & R) Program Benefits Metrics,” must be presented in a broader context, since many other initiatives may be affecting them during the same period of time as the implementation and benefits phases of an RCM project. However, the metrics relating to the new RCM based program may have to  be tracked for longer, if all expected benefits haven’t been realized, or implementation is taking a long time.

Again it is emphasized that only a few of the metrics in the following tables may be meaningful and that those presented are not the only ones available. In the consensus workshop it was suggested, without any objection, that as few as 6 or 8 metrics may be all that are needed to make the case for an RCM Project and to determine benefits derived from it. Metrics should be collected on the same asset studied prior to the decision to proceed with an RCM Project and for a period of time that provides a true representation of each value for valid comparison and characterization of “before” and “after” performance.

Table 10 - RCM Based  M & R Program Benefits Metrics

Note 1: Where a metric involves labor hours, it may be useful to break out subsets by trade category (e.g., Electrical, Mechanical, etc., )

Note 2: It has been useful in some instances to distinguish between labor hours and replacement parts cost for repair of the primary asset subjected to RCM analysis and conversion to a new program and labor hours and replacement parts cost for collateral damage to secondary assets beyond the primary asset.

Consistent with the goal of RCM Scorecard to measure and evaluate benefits (or lack of them) after an RCM based maintenance program is implemented, the last table, entitled  Table 11 - Benefits Phase RCM Based M & R Program KPI’s,  below, contains “traditional metrics.” In the same vain as was used for the metrics in the table above, these “traditional metrics” should be used for comparison with those listed for the “old” program. See Table 2 on Page 8.

Table 11 – Benefits Phase RCM Based  M & R Program KPI’s

Because RCM tasks may lead to correction of many problems previously tolerated, the metrics from the table above may be deceiving shortly after implementation and not be well received, unless analyzed and explained very carefully. For example, it is not uncommon to see growth in work orders and labor hours for maintenance as RCM action items are implemented. This is due to the fact that many problems either not evident or tolerated under the old program are identified for correction under the new program. This “hump” in work orders and labor hours must be overcome before positive results, reflected in other benefits, are realized in other metrics. It may take 12 to 18 months to work through this. For that reason, any of the metrics used during the Benefits Phase should be tracked for at least this long or longer after the end of the Implementation Phase of an RCM Project.

Some chronic problems may not yield to an RCM solution or other methodology, such as Root Cause Failure Analysis follow up actions. It may be useful to report metrics, such as failure rates, on these items separately or with caveats explaining the situation.

Interpretation of RCM Project Metrics or KPI’s

As illustrated in the diagram entitled “RCM Scorecard Metrics Relationships” (Figure 1) on page 2 of this document, Benefits Phase Metrics are compared to Baseline and Decision Metrics. Conditions before RCM are compared to conditions after RCM to determine gain (or loss) resulting from the investment of resources (money, labor and time). In general, desirable trends in the metrics or KPI’s are as follows:

Summary

The RCM Scorecard presents a menu from which metrics may be selected to aid in deciding whether or not to proceed with an RCM Project. Once the decision is made to proceed, it provides metrics to use to evaluate project progress (during analysis and implementation phases) and results (during the benefits phase). Many of the metrics are representative of what have been used in the past in actual projects. Other metrics may be added or substituted, as long as the principles of comparison for like assets and operating conditions are followed.

Glossary of RCM Scorecard Terms, Abbreviations and Definitions

Analysis Phase of an RCM Project – The period during which RCM analysis is in progress to determine what maintenance strategy should be performed on an asset.  A portion of the Analysis Phase may overlap with the Implementation and the Benefits Phases of an RCM Project.

Asset Utilization – Operating (Calendar) Time divided by Total (Calendar) Time in a specific period (Month Quarter, Year) times 100 to give the percentage of total calendar time that an asset runs.

Availability – The percentage of time an asset is available to run a product or provide a service. Some organizations may use the term “Operational Availability – A₀” which infers readiness for functional performance such as for a military mission, power generation, or transportation of passengers or freight.

Benefits Phase of an RCM Project – The period starting with regular execution of the first task or other action item (such as cancellation of an “old” program task proven of no value) resulting from an RCM analysis. The Benefit Phase may overlap Analysis and Implementation Phases of an RCM project. The period is characterized by adoption, calculation and evaluation of RCM based program benefits metrics and their trends. These are used to evaluate effectiveness of efforts aimed at failure mitigation, avoidance of functional degradation or failure elimination. This phase, usually divided into monthly or yearly intervals, may end at a time established by management or may be ongoing until benefits of the entire RCM effort have been fully realized.

Capacity Factor - The ratio of actual output divided by rated output. As commonly used in the Electric Power Generating Industry, it is the ratio of actual Megawatt Hours produced on an annual basis to the  Megawatt Hours that could have been produced during that period if the plant was operating at 100% of its rated output every hour of the year.

Condition Directed (CD) Task– See On Condition or Condition Directed (CD) Task.

Corrective Maintenance (CM) – Unscheduled (until requirement emerges) work to restore the functional capabilities of a malfunctioning or failed asset. This includes repeat maintenance which is labor expended after a first attempt at Emergency/Demand Maintenance has not restored  required function(s) of an asset. Corrective maintenance is a subset of Emergency/Demand Maintenance and is reactive work. A goal of a maintenance and reliability program should be to reduce corrective maintenance to as low as possible.

Consumables – Materials such as small components of an asset (nuts, bolts, washers, gaskets, paint, sealers, light bulbs, fuses, thermal lagging, small inexpensive parts etc.,) used or replaced in the course of maintenance and/or operation, which are disposed of and not repaired or restored to their original location. Some organizations place a monetary value on what is defined as consumable (e.g., <US$50.00). Materials such as lubricants and wiping rags are considered consumed even though they may ultimately be recycled through cleaning and reused in another portion of an asset or plant.

Critical Failure – A failure involving loss of function or secondary damage that could have a direct adverse effect on operating safety of an asset or safety of people that could be affected by its failure.

Critical Failure Mode – A failure mode whose ultimate effect can be a critical failure. If critical/operational, the failure has economic consequences, such as loss of revenue or profits.

Design Modification – An alteration to the configuration of an asset or its process (in this case driven by the RCM Analysis) that improves its reliability, safety margin or operational performance or makes a formally hidden failure evident to operators and maintainers in the course of their normal duties. Labor hours spent on design modifications are categorized separately (not included in PM or Emergency/Demand categories).

Decision Phase of an RCM Project – The period during which a determination, is made using a selection of metrics, measures or Key performance Indicators (KPI’s) as to whether or not an RCM Project will meet an organization’s investment criteria and for improvement in safety and/or economic performance. The improvement will be created by execution of a maintenance program based on principles of RCM. The project may involve a critical system, set of systems, a vehicle or fleet of vehicles, a plant or set of plants that produce a product or a facility or set of facilities that provide services such as utility services.

Emergency/Demand Maintenance or Reactive Work – Unscheduled reactive repairs performed on an asset so that the equipment may be restarted.  These jobs can range from minor adjustments to temporary or complete replacement of a component or asset.  Maintenance work is performed on an unplanned basis only a short time (e.g., within 48 to 72 hours) after a specific, unanticipated failure event. Some planning may be performed once the need for emergency/demand maintenance is recognized. Emergency/Demand Maintenance falls outside of the PM program and can be classified as reactive maintenance. Corrective maintenance is a subset of Emergency/Demand Maintenance. The definition of an “emergency” and “demand” depends upon the context in which the asset is operating or is to operate and the consequences of an impending or actual functional failure on safety (of people, environment or the asset), operating performance and/or economic factors involved.

Failure-Finding (FF) Tasks – Periodic or fixed interval tasks performed to detect the failure of a hidden function. These failures will not be evident to the operating or maintenance crews while performing their normal duties and require overt action to find a problem. FF Tasks are a subset of Preventive Maintenance. Failure finding tasks are inclusive of the tasks required to restore the failure found. FF tasks may be incorporated into operational procedures.

Failure Mode – The specific manner of failure; the circumstances or sequence of events, which leads to a functional failure

Failure Frequency – number of failures for a component, equipment or asset per unit of time (Month, Quarter or Year) or per some multiple of operating hours (e.g., per 1000 operating hours)

Failure Rate – A ratio (per Nowlan & Heap). The number of failures of a component, specific equipment or of a whole asset during a specified period divided by the total number of all failures in all similar components equipment or asset in operation during that period, usually expressed in numbers of failures per period of time (e.g., months or years) or per number of operating hours. May be qualified by certain conditions. Other measures of failure impact, such as mean time between failures for a given asset may be used instead of the Nowlan & Heap (United Airlines) one.

Function – The primary and/or secondary purposes of an asset or its normal or characteristic actions, sometimes defined in terms of performance capabilities.

Functional Failure – Failure of an item to perform its primary and/or secondary purposes or its normal and/or characteristic actions within specified limits.

Heat Rate – A measure of the efficiency of a plant in converting one form or source of energy (such as coal, oil or gas) into another (such as electricity). Typically this is measured in British Thermal Units (BTU’s) per Megawatt Hour in electricity generating plants. The lower the heat rate, the higher the efficiency in conversion. Since fuel is the major cost factor in production of electrical energy, Heat Rate is an important measure of a plant efficiency and potential profitability. Application of the best maintenance practices can greatly affect plant efficiency.

Hidden Function – A function whose failure will not be evident to operating or maintenance personnel during performance of their normal duties. Examples are a pressure gauge that indicates a normal condition but in fact has “stuck” and cannot change position, and a relay switch that should close to energize a standby pump when pressure drops below a specified value but cannot function because it has lost its power source.

Hidden Functional Failure – A failure that is not evident to either operators or maintainers in the course of their normal duties, unless and until the function is needed but not performed. The cause of such failures will also be hidden.

Implementation Phase (of an RCM Project) – The period beginning with preparation for execution of the first RCM-based recommendation for a revised or new maintenance and reliability strategy. The Implementation phase ends with initial execution of the last recommended action item of an RCM Project for an asset. The Implementation Phase may overlap with both Analysis and Benefits Phases of an RCM Project. Implementation involves management of change, design of the new strategy and its execution. The most  successful implementations use an organized approach such as the Sheuhart “Plan, Do, Check, Act” methodology articulated in Six Sigma and other problem solving processes.  (See www.isixsigma.com).   

Implemented Task or Decision – An RCM project action item that has been formally executed for the first time as part of an RCM based maintenance program. For tasks this means it has been incorporated into an approved step-by-step procedure (with or without other RCM tasks), formally scheduled and carried out at least once by personnel who have been oriented or trained (if needed) to carry it out. For RCM based decisions, such as RTF items which previously required a task which was not applicable and/or effective and other old program tasks for which there is no justification, this means that all steps have been taken to exclude them from the new program.

Item of Interest – An issue raised during RCM analysis that cannot be solved using RCM Methodology. During any RCM analysis, a number of issues are raised which are unrelated to the task at hand. Many of the issues are important and may indicate problems that the organization should address in another forum. Dwelling on them interrupts the RCM analysis process. To refocus analysis team efforts quickly, these items are simply listed as “Items of Interest” and reported along with the RCM analysis results to the project sponsor.

Key Performance Indicators (KPI’s) – Metrics or measures that may be used to evaluate how well an asset is carrying out its function. A KPI usually can be compared to some reference, such as the designed capability, accepted industry measure or national or internationally accepted value.

Lost Production or Lost Production Opportunity – The result of unscheduled downtime that consumes time previously scheduled for creation of a product or service. Cost of lost production equals the production rate times the number of hours of unscheduled downtime experienced plus the overtime cost for labor to make up the lost production, if this is possible in the calendar time remaining in a given operating period.

Lubrication Task – A time directed task involving addition or exchange of lubricant (such as grease or oil). These may be intrusive or non-intrusive. Obtaining a lubricant sample for purposes of analysis is generally considered to be an on-condition or condition directed (CD) task

Maintenance Backlog – Represents the maintenance work planned to be done at some time in the (near) future, usually expressed in labor hours and weeks, commonly on a graph where all labor hours (including support labor hours such as those expended for planning) are plotted against weeks in the future for a facility. Some maintenance may be “deferred” beyond the normal period for calculation of maintenance period for a wide variety of reasons, such as expected date of receipt of parts needed for a repair action.  

On-Condition or Condition Directed (CD) Tasks – Scheduled, preplanned,  periodic maintenance tasks performed at specific times in calendar or operational time to detect the onset of potential failures or a symptom that indicates the onset of failure. These may also be called Predictive Maintenance (PdM) tasks. When a CD task results in finding the onset of a failure or a symptom indicating the onset of failure, a task is scheduled to mitigate the problem and ensure the functions of the asset are maintained or restored. Labor hours expended to maintain or restore the asset functions resulting from condition monitoring or a predictive task are categorized, along with the CD Task labor, as Preventive Maintenance (PM) labor hours. CD tasks are inclusive of the repair or restoration tasks that flow from the monitoring tasks used to detect the onset of functional failure. A goal of an RCM Project should be to maximize on-condition maintenance, since it requires no action other than monitoring until a condition directs otherwise.

Operating Procedure – A detailed step-by-step written instruction and/or checklist(s) used to start up, run or shutdown an asset in the most safe, economical, productive and effective way. Changes initiated through RCM analysis are usually intended to eliminate or mitigate failure modes resulting from human error or to alter the way the equipment is operated in order to protect it from functional failure. This may be done to protect the environment, the people who might be affected by a failure or the quality of the product or service provided by it. Failure Finding Tasks are often incorporated into operating procedures as the most logical and convenient way of performing them.

Operating Speed Rate – Total Number of Units (of Product or Service) Produced times Theoretical Cycle Time divided by Actual Cycle Time and expressed as a decimal number equal to1.00 or (usually) less. See Speed Rate. Used in Overall Equipment Effectiveness calculation.

Overall Equipment Effectiveness (OEE)– A reliability measure that compares the amount of time a machine was running at an expected speed and manufacturing good quality product to the time it was scheduled to do so. One source (Hanson – See Page 3)  defines it mathematically  as Availability times Performance Efficiency times Quality Rate or (Runtime divided by Scheduled Time) times Operating Speed Rate times Quality Rate. Other sources may use different formulae.

Overtime Labor Hours – Labor hours performed for which a premium is paid (e.g., 50% of base hourly rate). Rates for premium pay and when they are to be paid may be established by organization policy, law, regulation or negotiation.

Performance Efficiency – Net Operating Rate (which is 1.0 by definition) times Operating Speed Rate

Planned Maintenance or Planned Work – Jobs of a defined scope where all labor, materials, tools, safety considerations and supporting documentation have been estimated, identified and/or assembled and coordination required to complete the job has been arranged with production or area management assuring availability of the asset before commencement of work. Includes all Time Directed, Condition Directed and Failure Finding Tasks and work resulting from RTF decisions and related (PM) labor hours, including the hours expended for repairs resulting from any problems identified through performance of these types of actions or decisions. See Preventive Maintenance.

PM Compliance – PM tasks accomplished divided by PM tasks scheduled (or required) times 100 and expressed as a percentage.

PM Labor Hours – All maintenance hours chargeable to a PM task or related action, including wrench time, wait time, planning and scheduling, testing, lockout/tagout and return to ready status.

Predictive Maintenance (PdM) - Those activities involving continuous or periodic monitoring, diagnosis and prognosis using a wide variety of installed, portable and remote (laboratory, vehicle, handheld or plant based) sensing instruments, human observation, and various analysis methods and tools in order to assess whether a functional failure of an asset will occur at some time in the future.

Predictive (PdM) Maintenance Labor Hours – Hours expended to monitor, maintain or restore asset functions resulting from a condition monitoring or predictive task. These hours are a subset of Preventive Maintenance labor hours.

Predictive Maintenance or PdM Task – See On-condition or Condition Directed (CD) Task. A measure of Predictive Maintenance Program effectiveness is the “Percent of PdM tasks that identify onset of functional failures on an annualized basis for an asset.” This is defined as the number of PdM tasks resulting in work orders requiring some sort of follow-up action divided by the total number of PdM tasks conducted on an asset on an annualized basis. Annualized implies any given 12 month period such as may coincide with an operating year, budget year or other 12 month period commonly in use for an asset.

Preventive Maintenance - PM – Scheduled, preplanned and periodic tasks such as servicing or inspection at specific points in calendar,  operational time or after specific events to assure the functional capabilities of an asset are maintained or restored to within acceptable limits. PM Tasks are the sum of all TD, CD & FF Tasks and RTF Decisions. Also may be called Planned Maintenance. In this context an RTF Decision leads to a conscious plan for restoration to occur after failure in order to reduce overall material cost and labor hours or to meet other goals of the maintenance and reliability program.

Protective Functions – Capabilities of an asset designed (as delivered or a subsequently modified) to preserve its function, quality of the product, meet legal or regulatory requirements and/or to protect against damage to the asset itself, the environment around it (including surrounding communities) and/or the people whose safety may be affected if the functions fail.

Quality Rate – The number of “good” units divided by the total number of units produced, a factor expressed as a fraction or a decimal number equal to or (usually) less than 1.00. Included in calculation of Overall Equipment Effectiveness and Total Effective Equipment Performance.

Repeat Maintenance – Maintenance conducted a second time on an asset to restore its functionality. Repeat maintenance is a subset of corrective maintenance. Repeat maintenance is an indicator of the effectiveness of a maintenance and reliability program. A goal of a maintenance and reliability program should be to eliminate repeat maintenance.

Rework Rate – The percentage of product produced that must be processed further (or again) to correct defects so as to meet the required (prime) quality standards, and thus commanding the highest sales price.

Rework Task – The scheduled removal of specific components of an asset to perform whatever maintenance tasks are necessary to ensure the asset meets its defined condition, level of reliability and functional performance standards. Referred to as an overhaul task in some organizations.

Run-to-Failure (RTF) Decisions – Deliberate choices to allow functional failures under certain conditions of acceptable risk. Usually made when a failure has little or no safety, environmental and/or economic consequences. May lead to decisions to cancel PM’s called out by the  “old” pre-RCM program for which there is no link to a failure mode identified in RCM analysis. Run-to-Failure may also be a de-facto decision when no applicable and effective task can be found to mitigate or eliminate a valid failure mode. If safety, critical operations or environment is of concern a design modification may be appropriate or a new PdM technology for monitoring may be acquired to detect the onset of degradation leading to failure. In such circumstances an action item to resolve RTF de-facto situations should remain open and be held at a high priority until resolved. Usually, there are no RTF decisions identifiable from the “old,” pre-RCM program. RTF Decisions are a subset of total PM Program Tasks.

Scheduled Downtime – Time (usually measured in hours or days) to do required work on an asset that is on a finalized periodic (e.g., weekly or monthly) schedule. Synonyms include shutdown, outage and overhaul period.

Scrap Rate – The amount (tons, widgets, etc.,) of irreversibly damaged product divided by the amount of total product (in the same units) produced by an asset. Damaged product must be scrapped. That is, recycled or disposed of and generally can’t be sold at a price that recovers its total cost of production. Usually expressed as a percentage of Throughput or Output.

Speed Rate - The ratio of Theoretical Cycle Time divided by Actual Cycle Time where Theoretical Cycle time equals Ideal Speed (Equipment Capacity as Designed or Highest Accredited Speed, if higher) and Actual Cycle Time equals Runtime divided by Actual Amount Produced. This yields a decimal number equal to or (usually) less than 1.00. Used in calculation of Total Effective Equipment Performance (TEEP).

Task  or Tasks – Specified maintenance action(s) taken to mitigate, prevent or identify the onset of or presence of an actual functional failure in an asset

Task Periodicity – Frequency with which a specified maintenance action is taken on the same asset.

Throughput or Output– The number of units of product or service delivered in a specific period of time. May be expressed in tons or barrels, gallons per day, week, month or  year, widgets per hour, megawatts-hours, etc.,

Time Directed (TD) Tasks – Periodic actions or tasks aimed directly at failure prevention or retardation, a subset of Preventive Maintenance. There are two types of TD actions or tasks:

            Intrusive (TDI) Tasks –Actions requiring asset or process interruption where human error or just  executing the task (in and of itself) may cause a functional failure upon resumption of operations after some inspections, adjustments and lubrication tasks requiring shutdown/restart, tagout, opening or disassembly. Intrusion implies introduction of induced risk of functional failure caused by the maintenance action itself. A goal of an RCM Project should be to minimize time directed intrusive maintenance tasks.

            Non-Intrusive (TDN) Tasks– Actions not requiring process or asset interruption, equipment shutdown, tagout, entry or disassembly that minimize the possibility of human error that could cause a functional failure.

Total Cost to Perform Maintenance – The total cost of labor,  material (Including cost of replacement parts) and overhead charged to a specific asset (or an entire facility) over a set period of time, including all maintenance support (indirect labor) personnel cost, contracted (outsourced) maintenance and related expenses (transportation, packaging, storage, handling), training and annual capital investment in tools, instrumentation and materials used to maintain an asset as well as allocated cost of utilities, insurance, taxes and factory supplies and consumables used by maintenance personnel in their daily work.

Total Cost of Replacement Parts – Money spent annually to replace failed, worn or scheduled replacement components on a given asset (or an entire facility), a subset of Total Cost to Perform Maintenance.

Total Effective Equipment Performance – TEEP - Asset Utilization times Speed Rate times Quality Rate, where Asset Utilization is Operating (Calendar) Time divided by Total (Calendar) Time, Speed Rate equals Theoretical Cycle Time or Ideal Speed (for equipment capacity as designed or accredited capacity, if higher, expressed in time (seconds, minutes) for each unit produced) divided by Actual Cycle Time (Runtime divided by actual amount produced, in units of product or service), and where Quality Rate equals “Good” Units (or Hours of “Good” Service) Produced divided by Total Units (or hours of Any Service) Produced.

Total Maintenance Labor – The labor man hours available from personnel to conduct an M & R program, including all contracted, temporary and full time repair, planning and scheduling, support, supervisory, management and any others authorized to charge against work orders for an asset or a whole plant 

Total RCM Program Decisions - Sum of all TDI, TDN, CD, FF Tasks and RTF Decisions

Unplanned work – See Corrective Maintenance

Unscheduled Downtime – The amount of time an asset is not capable of running due to need for unscheduled repairs, i.e., repair work not on the finalized periodic (e.g., weekly, monthly or annual) schedule plus the amount of time beyond that formally allocated for scheduled downtime or scheduled outage. (For example if a formally scheduled outage runs 8 hours longer than scheduled, the 8 hours should be categorized as unscheduled downtime and added to the total for the period(s) to which the metric applies. Downtime includes time waiting for parts. A unit that is capable of partial functionality is not “down” if it is operating at some level of output meeting minimum quality standards.

Yield - Throughput minus waste or scrap. Yield may be categorized into grades by level of quality (e.g., Prime, Seconds, etc.,)