Explicit and implicit methods for probabilistic common-cause failure analysis

The occurrence of a probabilistic common-cause failure (PCCF) in a system results in failures of multiple system components with different probabilities. A PCCF can be caused by external shocks or propagated failures originating from some components within the system. This paper proposes an explicit method and an implicit method to analyze the reliability of systems subject to internal or external PCCFs. Both methods can handle any arbitrary types of time-to-failure distributions for the system components. Both of the proposed methods are illustrated through detailed analyses of an example computer system. Applicability and advantages are also discussed and compared for the two methods.