The three constraints (systematic capability constraint, architectural constraint, and probabilistic performance metric constraint) that are implied by requirements per international safety standards IEC 61511 and IEC 61508 to determine the safety integrity level...
In performance based functional safety standards, safety function designs are verified using specified metrics. A key metric for process industry designs is called average Probability of Failure on Demand (PFDavg). After several studies of many field failure and proof...
Prior Use (Proven In Use in 61508) equipment is when a documented assessment has shown that there is appropriate evidence, based on the previous use of the component, that the component is suitable for use in a particular application of a safety instrumented system at...
The functional safety standards, IEC 61508, IEC 61511, and ANSI/ISA 84.01 each specify the Safety Integrity Level performance parameter for Safety Instrumented Functions. For a Safety Instrumented Function to meet a specific Safety Integrity Level the sum of the...
Fault tolerant systems have been designed for safety critical applications including the protection of potentially dangerous industrial processes. These systems are typically evaluated and certified to functional safety standards with IEC 61508 by agencies like exida...
