Traditional RCM evolved from the airline industry in the age of mainframe computer systems. Computers enabled United Airlines to study early part failures and usage, leading to age exploration. From these and other studies, Nowlan and Heap disputed the cherished notion that all parts age. Nowlan and Heap worked before the advent of PCs and on large fleets of nearly identical airplanes with outstanding parts and work order records. Few companies maintain such detailed records outside the aerospace industry. Yet today,

• PCs are prevalent.

• Analysis extends to other engineering and support fields.

• Operating costs and public risks worries predominate analysis.

• More groups and people do analysis.

• More experience is available.

These factors ease RCM application in large installations today.

RCM standards and variations abound, while traditionalists advocate classic seven-step RCM. Practically, the best shelf RCM analysis pales beside imperfectly implemented analysis. Implementation is the practical goal of all RCM and the primary industrial operating companies' barrier in process, power, and electrical transmission and distribution industries. Unless implementation can be made easier, RCM costs will remain high. Theoretical correctness, tempered for practical acceptance, helps realize implementation. Analyses need not be perfect; they follow an 80/20 rule of effectively correct, readily implemented, in a flexible program that easily incorporates learning. Potential for error predominantly involves cost and operational impacts. Partitioning to identify safety and operational risks assures unacceptable consequences are never missed. Living maintenance improves information flow and discovers new opportunities. These extend the...