Improved accuracy in event tree analysis

This paper is concerned with the analysis of Event Trees where the branch point event causes are defined using Fault Tree structures. Attention is focussed on the non-trivial situation where there are dependencies amongst the branch point events. The dependencies are due to component failure events featuring in one or more of the fault trees. In these situations it is shown that analysis methods based on traditional fault tree analysis are both inaccurate and inefficient. A new approach using Binary Decision Diagrams is proposed which overcomes these deficiencies.