Safety Instrumented Function (SIF)
Definition - What does Safety Instrumented Function (SIF) mean?
A safety instrumented function (SIF) is a built in operation of a machine that takes the unit to a safe outcome if predetermined conditions are not complied with. The system involves the three elements of logic solver, sensor and final element. Safety instrument functions are also known as emergency shutdown systems, and safety shutdown systems. A similar system is a safety instrumented function, which takes a hazardous situation with a system to an acceptable risk level.
Safeopedia explains Safety Instrumented Function (SIF)
A safety instrumented function should be implemented when there is no other instrumental process by which process risk can be mitigated or eliminated. A component of a safety instrumented function is a safety integrated level, which is a measure of the performance of the safety system. This measure is used when introducing an SIF designed to reduce the hazards involved to a tolerable level of risk.