The Safety Integrity Level (SIL) is a measure of the safety system performance or probability of failure on demand that is a relative level of risk-reduction provided by a safety function, or to specify a target level of risk reduction. A SIL level is allocated to a SIF (Safety Instrumented Function) for specifying the safety integrity requirements to be achieved by a SIS (Safety Instrumented System) and applies to an entire system. A SIL is the four discreet integrity levels (SIL 1 – 4), the higher the SIL level, the higher the associated safety level that as the SIL level increases, typically the cost and complexity of the system also increase.
Related Definitions in the Project: The HSE Management; Engineering
