CEI IEC 61703-2001 pdf download
CEI IEC 61703-2001 pdf download.Mathematical expressions for reliability, availability, maintainability and maintenance support terms.
CEI IEC 61703 provides mathematical expressions for reliability, availability, maintainability and maintenance support measures defined in IEC 60050-191. The following classes of items are considered separately in this standard:
— 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 simple as possible, the following basic
mathematical models are 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.
To facilitate location of the full definition, the IEC 60050-191 reference for each term is shown (in parenthesis) immediately following each term, for example:
mean time to restoration [191-13-08J
The application of each dependability measure is illustrated by means of a simple example.
NOTE This standard is mainly applicable to hardware dependability, but many terms and their definitions may be applied to items containing software. Some of the software dependability aspects are explained in annex D.
2 Normative references
The following normative documents contain provisions which, through reference in this text, constitute provisions of this International Standard. For dated references, subsequent amendments to, or revisions of, any of these publications do not apply. However, parties to agreements based on this International Standard are encouraged to investigate the possibility of applying the most recent editions of the normative documents indicated below. For undated references, the latest edition of the normative document referred to applies. Members of IEC and ISO maintain registers of currently valid International Standards.
IEC 60050-191:1990, International Electrotechnica! Vocabulary (1EV) — Chapter 191:
Dependability and quality of service
ISO 3534-1:1993, Statistics — Vocabulary and symbols — Part 1: Probability and general statistical terms
3. Definitions
For the purpose of this International Standard, the terms and definitions of IEC 60050-191 and ISO 3534-1 apply. In addition, the following terms and definitions are used.
3.1 instantaneous restoration intensity (t)
limit, if it exists, of the quotient of the mean number of restorations of a repaired item in the time interval (t, 1 + Ot) and the duration of this interval, Ot, when the duration of the time interval tends to zero.CEI IEC 61703 pdf download.
