Application of fault trees and Bayesian networks for maintenance

The FMECA method allows apprehending the risks of failure to avoid them. It allows us to define the failure modes and their criticalities. This helps us choose the right actions for critical system components. The second tool Fault Tree FT or often is a method used to identify all the probable causes of a feared event and thus make a rapid diagnosis. From the built FT, we defined the most probable paths the critical paths that lead to the feared event. The probabilities of occurrence of the top event and of the intermediate events are governed by those of the base events. The occurrence of these can be modeled by Weibull's law. For this we have used Bayesian networks relating to the FT thus constructed. Our major contribution is the introduction of this notion of calculating the contributions of the paths in a BN for the occurrence of the system failure event.