7. Glossary

BPCS ( Basic Process Control System )

Process supervision system.

Criticality

The criticality of a scenario corresponds to its probability/severity ratio. This pairing is generally reported in a matrix to assess the acceptability of the risk (such as the criticality matrix introduced in the circular of May 10, 2010).

LOPA

Layer Of Protection Analysis.

SIL level

A discrete level (of four possible) for specifying the safety integrity requirements of the safety functions to be allocated to safety-related E/E/PE systems. Safety integrity level 4 has the highest degree of integrity; level 1 has the lowest.

SIF ( Safety Instrumented System )

A safety instrumented function...