1. Context

The control of risks generated by industrial activities requires the implementation of risk control measures (RCMs), also commonly referred to as safety barriers. The aim of these safety barriers is to reduce the criticality of risks. Risk reduction generally takes the form of prevention, the aim of which is to reduce the probability of a hazardous situation occurring, and mitigation/protection, the aim of which is to limit the consequences if the hazardous situation could not have been avoided.

To reduce the probability of a hazardous situation occurring, manufacturers use various types of safety barriers, including safety instrumented systems (SIS).

The function of a SIS is to ensure the implementation of safety instrumented functions (SIF), for which an integrity level must be set. This level depends on the criticality of the hazardous...