Terminology and definitions
Nowlan and Heap's reliability-based maintenance method

This section presents translations of the main terms and definitions used in 1978 by Nowlan and Heap to define their RCM-N&H method, taken in full from the glossary in their report. English technical terms have been used with their acronyms. It is essential to note that since that date, additional and new definitions have been the subject of national and international standards, in particular the European standard CEN 13306 . For definitions relating to RCM methods, please refer to