The hazard scenarios that have been determined by the PHA/HAZID activity to require further risk reduction will undergo further analysis in a workshop environment to identify additional safeguards, or to identify other safeguards that will reduce the risk to a tolerable level. The residual risk will indicate if a safety function is required to reduce risk further, and if it is, the required performance level, SIL/PLr (risk reduction requirement) of the safety function will be determined.
In the machine safety environment this activity is often referred to as SIL or PLr Determination because the performance requirement of a safety function is expressed as a Safety Integrity Level (SIL) per the requirements of IEC62061; or as a Required Performance Level (PLr) per the requirements of ISO13849-1.
FSE Global consultants provide procedures and tools to run the SIL/PLr determination process; offer expert advice on safety functions that are difficult to analyse; and deliver a comprehensive report detailing every aspect of the SIL/PLr determination workshop.
