Effect of Truncated Input Parameter Distribution on the Integrity of Safety Instrumented Systems Under Epistemic Uncertainty

摘要: Safety instrumented system (SIS) is widely applied to reduce or prevent risk in industry. Practical SIS commonly meets with epistemic uncertainty arising from incompleteness of knowledge on various input parameters due lack data. Epistemic can be reduced by collecting more lead variation probability failure perform its intended functions demand (PFD) for an SIS. This paper employs the complementary cumulative distribution function PFD define exceedance (EP) that exceeds a prescribed value. Sensitivity analysis further investigated, analyzing effect epistemically uncertain parameter truncated EP We have derived analytic expression evaluating effect, and only evaluation needed estimate effects all parameters. Two examples are employed demonstrate applicability proposed method. compare nontruncated situations. Their results converge same ones as region decreases zero. When less than 10–3 , corresponding approximated case lower computational cost.