1. Scope 1.1
This Standard lists terms and definitions, primarily intended for the
description of reliability, availability, maintainability, and maintenance
support aspects of items.
It is a document relating to Chapter 191 of the International
Electrotechnical Vocabulary (IEV), IEC 50 (191). Extra notes are used in this
Standard to clarify certain definitions taken from IEV.
The terminology is based on an engineering approach, but it is also adapted
to mathematical modelling techniques which are fundamental to the application
of the terms.
Appendix A contains definitions of modifiers (see Clause 2.3.7) and related
terms. Related subjects, such as probabilistic and statistical concepts, are
treated only when they are needed to facilitate the reading and understanding
of this Standard. Other international standards should be consulted when
necessary. In particular, IEC 50 (191) should be consulted for a more complete
list of terms and definitions.
Note: Where more than one term is specified in the title of a definition, the
first term is preferred; the other(s) may be used as synonyms.