Description

BS PD IEC/TR 63039 – Probabilistic risk analysis of technological systems. Estimation of final event rate at a given initial state

BS PD IEC/TR 63039:2016 provides guidance on probabilistic risk analysis (hereafter referred to as riskanalysis) for the systems composed of electrotechnical items and is applicable (but notlimited) to all electrotechnical industries where risk analyses are performed.

This document deals with the following topics from the perspective of risk analysis:

defining the essential terms and concepts;
specifying the types of events;
classifying the occurrences of events;
describing the usage of modified symbols and methods of graphical representation forETA, FTA and Markov techniques for applying those modified techniques complementarilyto the complex systems;
suggesting ways to handle the event frequency/rate of complex systems;
suggesting ways to estimate the event frequency/rate based on risk monitoring;
providing illustrative and practical examples.

The relationship between the events covered by this document and associated risks aredescribed in Table 1. Risk is defined as the effect of uncertainty on objectives (see 3.1.1).The uncertainty is here assumed to be composed of two elements: the epistemic and aleatory.The epistemic is categorised into the known and unknown, and the effect of the aleatory isclassified into the controlled and the uncontrolled, respectively. Therefore, the risk associatedwith the known event of which impact is controlled is the controlled risk, and the riskassociated with the known event of which impact is not controlled is the uncontrolled risk.Favourable meta-risk is of an unknown event of which impact can be casually controlled evenif this unknown event appears, and unfavourable meta-risk is of an unknown event of whichimpact cannot be controlled.

For example, the risks resulting from random hardware failures of electrotechnical items willbe categorised into the controlled or uncontrolled risks, while the risks owing to software bugscould be classified into the favourable or unfavourable meta-risks. This document covers thecontrolled and uncontrolled risks resulting from the events that can be assumed to occurrandomly and independently of time.

Cross References:
IEC 60050-192
IEC 61703
ISO Guide 73:2009
ISO 9000:2015
ISO 31000:2009
IEC/ISO 31010:2009
IEC 60050-192:2015
IEC 60300-3-1:2003
IEC 61703:2001
IEC 61078:2006
IEC 60812:2006
IEC 61508
IEC 61882:2016
IEC 61508
IEC 61025:2006
IEC 61165:2006
IEC 62502:2010
IEC 61508-6
ISO/IEC Guide 51:2014
IEC 61508-1:1998
IEC 61508-4:2010
IEC 61508-4:1998
IEC 61511
IEC 61508-1:2010
IEC 61508-5