5. What do we mean by technical MMR?

5.1 SIS (safety instrumented system)

SIS: A set of elements designed to ensure that a system is put into a safe state (i.e. a stable state presenting no risk to people or the environment) when predefined thresholds are reached.

The majority of SISs encountered in industry are made up of three functional blocks, as shown in the figure "Simplified SIS architecture diagram":

• a "detection" block, responsible for identifying the drift of a parameter (pressure, temperature, etc.) towards a dangerous state, this dangerous state often being defined by a threshold value;

• a "logic processing" block, responsible for receiving the signal from the detection devices and processing it to control...