A process-oriented simulation model for common cause failures

A process-oriented simulation model (POS-model) for common cause failures (CCF) is presented. This model consists of the following sequence of stochastic variables: time of CCF impact, number of components in the group affected by the impact, times of failure of the impacted components, time of detection of the CCF-process. As compared to the considerable number of modeling approaches that directly yield expressions for the probability of the number of failed components the POS-model seems more complicated but – thanks to a variety of interesting properties – might be useful as a complementary analytical tool. The results of a couple of applications to available field data are presented. In these exploratory examples, the adaptability of the POS-model is demonstrated and results are compared with various other modeling approaches. Finally, further planned development steps for the POS-model are addressed, primarily the optimization of parameter estimation.