SILability and safety functions
Industrial facilities and equipment commonly use automatic safety functions to control risks. These functions are often known as Safety Instrumented Functions (SIFs) or Instrumented Protective Functions (IPFs). Their purpose is to monitor specific parameters such as the temperature of a reactor, position of a moving part, speed of a motor, or the presence of a person or object using a sensor. When specified conditions are met, such as a temperature limit, the function takes action to prevent harm.
During the conceptual design phase of a SIF, the design team should confirm that the proposed SIF design is sufficiently reliable. This task, known as SIL verification, is a requirement of international standards and involves a calculation of the SIF’s probability of failure. SILability helps the reliability engineer to execute SIL verification correctly and efficiently.