Bayesian analysis using binary decision diagrams

Binary Decision Diagrams (BDDs) have been shown to be efficient for the numerical evaluation of the reliability of complex systems. They achieve exact results where Fault Tree Analysis could generally produce only bounds. In this paper the approach to systems evaluation using a Bayesian method in conjunction with BDDs is explored. The advantages of the approach are discussed with respect to both efficiency and the ability to deal with dependency within the system in a natural manner. As an illustration a simple pump configuration is considered which features a dependency. The results demonstrate both the flexibility of the approach and the ease of dealing with the additional complexity of dependency. To gain full benefit of the Bayesian analysis, though, it is necessary to use numerical integration. This will be illustrated using the pump example.