hardware fault tolerance (SIL) (HFT)

Hardware Fault Tolerance(HFT), together with Safe Failure Fraction(SFF), determines the Safety Integrity Levels( SIL) of systems.

The Hardware Fault Tolerance indicates the number that a system can withstand without failing. The higher the HFT value, the higher the availability. Fail-safe and fault-tolerant systems accordingly have the highest of the three HFT values, 0, 1 and 2.