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The argument against "Streamlined"
Reliability-centred Maintenance (RCM)
Phil Clarke, Director, The Asset Partnership
Reliability-centred Maintenance (RCM) is a technique for determining the preventive maintenance and inspection requirements of physical assets. It was originally developed by the commercial aviation industry in the 1970's in light of new understanding of the nature of failure. It is a rigorous and thorough process, an essential feature when dealing with aircraft airworthiness issues. In the late 1970s and early 1980s, asset managers in other industries recognised that RCM was equally applicable to any physical asset, not just aircraft. RCM was adopted for use in industries as diverse as power generation, transmission and distribution, petro-chemical, manufacturing, mining and transport to name but a few. RCM is now generally accepted by most authorities in the field of physical asset management as being the only defensible technique for determining the maintenance requirements of assets in their operating context. A feature of RCM in its original form as embodied in the original RCM work of Stan Noland and Hard Heap is that involves considerable rigour in achieving its intended benefits. This realisation has spurned a number of "Streamlined" or "stripped down" imitators of RCM that typically claim to achieve 80% of the benefits with 20% of the effort. The emergence of these streamlined techniques muddied the waters somewhat as to exactly what RCM is (and is not), and consequently SAE standard JA-1011 "Evaluation Criteria for Reliability-centred Maintenance (RCM) Processes was developed to define what can be called "RCM". So a physical asset manager is often faced with the option of going the JA-1011 Compliant or "Streamlined" RCM route. What are the "pros" and "cons" of each? Reliability-centred Maintenance
An understanding of what RCM is must begin with "true" RCM. Compliant RCM asks seven basic questions: • What are the Functions of the asset in its present operating context? • What Functional Failures can it suffer from? • What Failure Modes can cause each Functional Failure? • What are the effects of each Functional Failure and Failure Mode? • What would be the Consequences of each Functional Failure if it no attempt were made to • Can any proactive maintenance or inspection tasks be performed to prevent or predict the • What can be done if the task cannot be prevented or predicted? The first four questions are answered by performing a Failure Modes and Effects Analysis (FMEA). (International standards that relate to conducting an FMEA include US Department of Defence MIL STD 1629(A) and International Electrotechnical Commission IEC812.) If the FMEA is performed correctly, all Functions (question 1) and Functional Failures (question 2) and their related performance standards for the asset or system being analysed will be identified. Advocates of Compliant RCM will point out that this is a critical step in the maintenance analysis process as maintenance is really all about preserving function much rather than preventing failure. The third question seeks to identify all the feasible causes (Failure Modes) that will cause the loss of functions identified. Experienced Classical RCM analysts will not seek to identify all possible Failure Modes for each Functional Failure, but will assess probability of occurrence and severity of consequence. It is also important to identify Failure Modes to the appropriate level of "causation" that The Argument Against Streamlined Reliability-centred Maintenance Philip R. Clarke, Director, The Asset Partnership will allow them to be most effectively managed (ie, to a level of detail that will allow a cause much rather than a symptom to be dealt with). The fourth question (Failure Effects) identifies the physical effect of the failure if nothing was done to prevent or predict the failure. Aspects considered include any possible physical effects on safety, the environment, operations and maintenance costs. A "zero based" approach is taken so that all possible ultimate effects and consequences of the failure can be readily identified. It is with the fifth question that the "true" part of the RCM process begins. All RCM methodologies identify Functional Failures as being "Hidden" or "Evident". Hidden Failures are Functional Failures that will not be evident to operating crews in normal circumstances, and typically involve some form of protective device that is not "fail safe". It is a characteristic of Hidden Failures that they have no direct consequence by themselves, and only matter if some other failure occurs (eg, the failure of a fire extinguisher to operate will only matter if there is a fire). Evident failures are generally classified as having Safety, Environmental, Operational or Non Operational Consequences. A Functional Failure that has Safety Consequences is one that could cause loss of life or injury, while Environmental Consequences are failures that could cause a breach of an environmental standard or regulation. Failures with Operational Consequences will involve some loss of operational capability or cost over the direct cost of repair, while Non Operation Consequences involve failures where the only cost is the direct cost of repair. Clearly determining the consequences of failure is pivotal to the RCM process, and it is the consequence of failure that any proposed failure management policy must successfully deal with much rather than the failure itself. The sixth question involves assessing proactive failure management policies. These include On-Condition (or condition monitoring), Scheduled Restoration, Scheduled Discard, and Combination tasks. RCM sets out strict criteria for assessing the "technical feasibility" or "applicability" of these tasks in dealing with the failure mode being assessed. Applying criteria will determine if the task will in fact actually prevent or be able to predict that failure being considered, and if so, at what interval it should be carried out. The final question deals with those failures for which no technically feasible and worthwhile proactive task can be found. These are often referred to as the "Default Tasks", and include Failure Finding tasks for Hidden Failures only, No Scheduled Maintenance (or "run to failure"), and Redesign. Again, RCM sets out criteria for determining which option should be selected. The outputs of the RCM analysis will be a list of proposed maintenance tasks, their proposed intervals, and who should carry them out. These tasks are then "packaged" into maintenance schedules for implementation. Well known most commonly accepted RCM standards and methodologies include Reliability-centred Maintenance II (by John Moubray of Aladon Ltd), MIL STD 2173(AS) or NAVAIR 00-25-403 from the US Navy, and the original 1978 Reliability-centred Maintenance report by Nowlan and Heap. These standards and publications differ in detail, but have overall consistency in approach and application of methodology. Streamlined RCM
A number of "Streamlined" or "fast track" RCM methodologies (many software based) have been put forward by various organisations and authors in recent years. The main driving force behind these alternative approaches has been to overcome the perception that RCM is time consuming and a "resource consuming monster"! Many claim to achieve "80% of the benefit for 20%" of the effort of formal RCM. One difficulty in assessing the worth of Streamlined RCM approaches is their lack of consistency in overall approach or methodology. Many of these proprietary methodologies have taken different approaches to "streamlining" the basic RCM approach, so it is difficult to compare their overall worth. The next point to be considered is the "right" for these approaches to be called Reliability-centred Maintenance at all, be it "Streamlined" or otherwise. Many have reduced or removed altogether one or more of the steps or processes contained in the JA-1011 and RCM standards and methodologies outlined above. Consequently, they fail to qualify as being "Reliability-centred Maintenance" in any The Argument Against Streamlined Reliability-centred Maintenance Philip R. Clarke, Director, The Asset Partnership form when judged against internationally accepted standards. In short, they are not Reliability-centred Maintenance. So how typically have the Streamlined RCM approaches reduced the effort or resources required to carry out RCM? Functions: Most Streamlined RCM approaches only identify what RCM analysts would consider the primary or more obvious secondary functions. When they are recognised, they are often inadequately identified or quantified. Other and often significant secondary functions are excluded. Consequently, one of the fundamental tenants of responsible physical asset custodianship - that maintenance is all about preserving asset function - cannot be met. Functional Failures: If Functions are not recognised or inadequately quantified, then their associated Functional Failures will be similarly affected. Failure Modes: Many Streamlined RCM approaches advocate identifying only "significant" failure modes. Doing so entails considerable risk, for a failure mode that today is judged as not being significant might just be the one that could reduce your plant to a smoking ruin tomorrow. It is worth remembering that the failure of a seemingly insignificant light bulb on a control panel in the Perrier plant cost it $200 million in wasted product and half the company’s market share. Failure Consequences: It is the Streamlined RCM treatment of failure consequences that causes most concern. Many Streamlined RCM approaches display an inadequate or complete lack of understanding Hidden Failure consequences in particular, which in many applications could be positively lethal. Proactive and Default Task Selection: Many Streamlined RCM approaches seem to have substituted their own criteria or logic for determining if tasks are technically feasible or applicable in place of the well established and internationally accepted principles contained in RCM. These are often based on complete misconceptions (such as the frequency of a condition monitoring task is based exclusively on probability of failure much rather than rate of deterioration). This must bring in to serious question the merit of proposed tasks and their intervals that are identified. Inadequate definition of Functions, Functional Failures, and their associated Failure Modes may lead to many tasks that should have been identified to be omitted altogether. Many Streamlined RCM methodologies utilise software (often "driven" by an external consultant) to arrive at tasks and their intervals based on inputs from internal personnel or obtained from maintenance history. This has two implications. Firstly, there is an often irresistible temptation to "adapt" the inputs to get an output that seems "right". Secondly, the algorithm that calculates the answer based on the inputs is often not known or understood by the organisation accepting the outputs. "The computer told me to do it" is not defensible response in a court of law or any other forum on how maintenance task or task intervals were determined. RCM is "thoughtware", not software. Many of the advocates of Streamlined RCM also claim that they can "do it for you" based on their previous experience, your maintenance history and limited involvement of in house personnel. Unfortunately, this often leads to lack of confidence in the results (due to lack of understanding of the basis of decisions) and lack of ownership from internal personnel in the outputs. There is no chance of any enduring cultural or attitude change in the organisation when this approached is used. What Saving?
RCM has often unfairly received a bad name in some organisations due the perception that vast amounts of resources have been consumed on projects that have achieved little benefit. Closer examination of these "failed" projects often reveals that the "fault" lies with organisational deficiencies such as ill defined project objectives, inadequate or inappropriate resourcing, lack of training, or inadequate project planning and management, much rather than due to any intrinsic problem in the RCM processes itself. (It should be remembered that RCM originated in the aircraft industry, where tight and highly disciplined project management is far more prevalent than in industry in general.) The Argument Against Streamlined Reliability-centred Maintenance Philip R. Clarke, Director, The Asset Partnership This brings us to the question of how much reduction in effort or resources does Streamlined RCM really save? The RCM analysis is in fact just one step in an overall RCM Implementation Project. It is worth looking at the typical activities that might be involved in successfully implementing RCM. These are: • Set RCM project goals and objectives. • Select and appoint RCM Project Manager. • Determine Asset Functional Breakdown (ie, identify and logically group the assets to be • Conduct Criticality Assessment to prioritise assets for analysis. • Select and agree candidate assets for analysis. • Measure existing performance of assets (eg, reliability, maintenance costs, etc). • Scope analysis resource requirements. • Identify personnel to be involved in RCM analysis (either internal or external). • Arrange and provide analysis infrastructure (ie, computers, meeting rooms, etc) • Plan analysis sessions (when, where, and who). • Gather supporting documentation and information for analysis (ie, manuals, P&IDs, • Package RCM derived tasks into maintenance schedules (and policies). • Train personnel in any new maintenance tasks or procedures. • Carry out any "baseline" checks or tasks required. • Load new schedules in the Computerised Maintenance Management System (CMMS) • Monitor post implementation performance. From this list it is evident that the actual RCM analysis is just one activity of many required to successfully implement RCM. Most of these steps need to be carried out regardless of the RCM approach, be it JA-1011 compliant or Streamlined. This means that the savings from using short cut RCM methods are far less than they would appear at first. In reality, any savings are often illusory. The key to successfully implementing RCM lies in the overall approach, project management, and commitment from the organisation. Without these elements any RCM project will be inevitably doomed to a less than optimum result. Managing Risk
Increasingly in the 21st century, the effective management of risk is an over-riding factor in the management of complex industrial assets. In Australia, the management of risk has been changed forever by the tragic events at ESSO’s Longford gas plant on the 25 September 1998. Two workers died and eight were injured when a super cooled heat exchanger failed catastrophically when hot oil was introduced into it. The state of Victoria was essentially without gas supplies for two weeks, causing massive economic loss. ESSO was subsequently convicted of 11 charges under the Occupational Health and Safety Act and fined nearly $2 million. In his summing up the presiding judge, Supreme Court Justice Philip Cummins, left no doubt as to where he thought responsibility rested: “The events of September 25 1998 were the responsibility of ESSO - no one else. Their cause was grievous, foreseeable and avoidable. The consequence was grievous, tragic and avoidable." he said. “To use the term ‘accident’ denotes a lack of understanding of responsibility and a lack of understanding of cause." The Argument Against Streamlined Reliability-centred Maintenance Philip R. Clarke, Director, The Asset Partnership ESSO is now facing class actions potentially totalling billions of dollars for the economic loss caused by the loss of gas supplies. In such circumstances, is it defensible the to use short cut techniques such as “Streamlined RCM” that could allow “grievous, foreseeable and avoidable” causes of catastrophic failure to go unidentified and untreated? That is the question that Physical Asset Managers will have to answer for themselves, and hopefully, not while standing in the dock in a court of law. Keeping Perspective
Perhaps an assessment of the true worth of JA-1011 compliant verses Streamlined RCM can be gained by looking at how organisations and society treat the management of financial assets. In the 15th Century, an Italian by the name of Luca Pacioli invented double entry booking keeping, a methodology that is still practised by accounting profession to this day. Every day, month and year, legions of accountants and clerks, managers, supervisors, operators, maintainers and others spend huge amounts of time helping to ensure that the company accounts balance to the cent. To suggest that we could employ "Streamlined" accounting to track 80% of the transactions for 20% of the effort would be met with ridicule and derision. Yet the worst that can happen if the company accounts are not properly balanced is that the company can go broke (and the directors go to gaol!) The entirely preventable catastrophic failure of physical assets can and has killed people as they did at Longford. Yet the same managers who would scoff at the suggestion of employing "Streamlined Accounting" will happily entertain the idea that short cut and superficial approaches such as Streamlined RCM for determining the maintenance requirements of their physical assets hold the key to the future profitability and well being of their organisations. In reality, the cost and effort required to implement JA-1011 compliant RCM is a fraction of the cost of acquiring and operating the assets. JA-1011 compliant RCM will provide many benefits to the organisation to ensure that they exercise responsible physical asset custodianship that cannot be matched by its Streamlined RCM imitators. Do RCM properly or not at all. As the old adage goes, if a job is worth doing, it is worth doing well. References
SAE, The Engineering Society For Advanced Mobility Land, Sea, Air and Space International, Standard JA1011, Evaluation Criteria for Reliability-centred Maintenance (RCM) Processes Reliability-centred Maintenance, F Stanley Nowlan & Howard F Heap, 1978, National Technical Information Service, Department of Commerce, Springfield VA. Reliability-centred Maintenance II, John Moubray, Industrial Press, 1997

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