A second group of “RCM” methodologies was developed in response to the perception that carrying out RCM was too resource intensive. These “light” or “express” methods work differently from RCM. Where true RCM begins with an analysis of equipment functions, functional failures and failure modes, these methods typically analyse the existing maintenance tasks with the objective of adjusting intervals and eliminating unnecessary maintenance. As a result they may sometimes be quicker to implement than classical RCM, but there is a real danger of failing to identify serious risks to production, safety or the environment due to design issues or missing maintenance.
The potential for confusion between “classical” and “light” methods was a key driver for the development of the US Society of Automotive Engineers (SAE) standard JA1011. This short document defines the requirements that any process must satisfy in order to be considered as RCM. A second standard, SAE JA1012, is longer and elaborates on the first document, including examples of possible RCM decision diagrams.
It isn’t uncommon for organisations starting out in RCM to get hung up choosing between versions of RCM. The truth is that an experienced RCM facilitator can work well with a number of full RCM standards, and the precise wording of a decision diagram should not make a significant difference to the quality of the maintenance schedules that are eventually produced.
Having said that, it obviously makes sense to start out with a version of RCM that will meet your needs in the long term. Using a standard that was designed for aircraft such as MSG-3 or AP 100-C22 to analyse a car body plant could result in unnecessary confusion because of differences in terminology and maintenance practice. Defence-related standards such as MIL HDBK 2173 or the UK DEF-STAN 00-45 are often used in the civilian world, but again they probably need some interpretation to fit with an industrial process. In practice, any standard is compliant with the two SAE standards JA1011 and JA1012 will probably work.