Safety Integrity Levels (SIL) Study
A Safety Integrity Level (SIL) measures the relative level of risk-reduction provided by a safety function. In simple terms a SIL is a measurement of performance required for a Safety Instrumented Function. Four SIL levels are described with SIL 4 being the most dependable and SIL 1 being the least dependable. A SIL is determined based on several quantitative factors such as development process and safety life cycle management