DEFINITIONS
Process Safety Time - PST
• the time period between a failure occurring in the process or the
basic process control system (with the potential to give rise to a
hazardous event) and the occurrence of the hazardous event if
the SIF is not performed.
Safety Instrumented Function Response Time -
SIFRT
• the time taken for the SIF to detect the abnormal condition and
respond to bring the process to a safe state and prevent the
hazard from occurring.
Slide 5
Challenges in Achieving Safety Instrumented Function Response Time for a Fast-Acting Process• K. Rampaul, A.
Barnwell & S. Sookhoo