What is the difference between RCM and LRCM?

You ask a very good question, and an important one.

RCM was developed in the 1970s by Nowlan and Heap and revealed to the maintenance world in their pivotal work performed at United Airways under U.S. government contract. Their report, entitled “Reliability Centered Maintenance”, was submitted on December 31, 1978 to the United States Secretary of Defense. The importance of RCM should not be underestimated.

RCM II, devised by John Moubray is an innovative implementation and commercialization of Nowlan and Heap’s RCM methodolgy. Moubray’s arguably brilliant contribution to RCM is the “facilitated review group meeting” technique. Using his method, subject matter experts, notably including experienced maintenance technicians and operators, participate in a series of structured meetings under the guidance of a trained RCM facilitator. The output from an RCM analysis is a concise data structure that thoroughly justifies and sets the maintenance plan. The maintenance plan consists of timed preventive maintenance activities targeting and mitigating the consequences of each reasonably likely failure mode. Those activities are to be carried out at specified intervals. The RCM derived plan is typically uploaded to a maintenance work order system (called the EAM or CMMS) that is used to manage and allocate the necessary resources and schedules.

Living RCM (LRCM) encompasses the entirety of RCM II. However LRCM recognizes that the initial RCM analysis and maintenance plan is a first approximation of reality based on the best recollection of the RCM participants at the moment of the analysis. The initial RCM analysis is often treated as a “one-time” project. That is, it is seldom revisited or systematically reviewed and updated. Yet maintenance technologies and operational contexts change frequently causing maintenance plans to become outdated and sub-optimal. Consequently LRCM extends the RCM thinking process beyond the initial RCM analysis to be revived incrementally as an integral part of day-to-day maintenance routine. RCM philosophy is applied continuously each time a maintenance work order is executed. Before a work order is closed LRCM ensures that two actions will have taken place: One, that any deviation between the initial RCM analysis (called “the RCM knowlege base”) and reality on the ground as observed by the technician, is revealed and eliminated through a special RCM knowledge feedback technique. Secondly, LRCM ensures that an error free record of each instance of an RCM failure mode and its ending event^[1] are documented accurately in the work order. Such rigor is essential for reliability analysis and maintenance decision modeling. The lack of accurate historical data of this type (called “age data”) is a well-known oversight in the practical EAM process. LRCM procedures augment EAM work order practice and  correct this flaw.

© 2015, Murray Wiseman. All rights reserved.

1. ^[1]An “ending event” refers to one of Failure, Potential Failure, or Suspension. ↩