Assessment of MMR failure probability and traceability
Principles for the assessment of the probability of failure in Risk Control Measures (RCM)

Although risk analyses such as RPA, HAZOP, etc., have been used in the chemical and oil industries since the 1980s, these studies were rarely quantified in terms of incident or accident probabilities; when they were, the assessments were almost always based on expert opinion.

The evolution of French regulations, marked among other things by the decree of September 29, 2005, has had far-reaching consequences for hazard studies and their risk analyses, since the French authorities now expect a high degree of traceability in the process of assessing the probability of occurrence of industrial accidents. This change requires :

• implement analysis methodologies that enable a quantified assessment of the probability of accident occurrence (e.g. bow-tie);

• justify the probabilities retained...