Gives mathematical expressions for reliability,availability, maintainability and maintenance supportmeasures defined in IEC 60050-191. The followingclasses of items are considered separately in thisstandard:- non-repaired items;- repaired items with zero time to restoration;- repaired items with non-zero time to restoration.In order to keep the mathematical formulae as simpleas possible, the following basic mathematical modelsare used to quantify dependability measures:- random variable (time to failure) for non-repaired items;- simple (ordinary) renewal process for repaired items with zero time to restoration;- simple (ordinary) alternating renewal process for repaired items with non-zero time to restoration.

? British Standards Institution 2013

Supersedes 00/402267 DC.
(12/2001)
Renumbered and superseded by BS EN 61703.
(09/2002)

IEC 61703 Ed. 1.0 - Identical