FAUNET: a program package for fault tree and network calculations

A program package for fault tree and network calculations is described. The package contains an algorithm for modularization of fault trees prior to the calculation of the minimal sets. For many fault trees the modularization will reduce the number and/or the order of the minimal sets so much that it becomes possible to perform exact probability calculations instead of using bounding techniques. A reduction-expansion algorithm for this purpose is described. The failure intensity formula for maintained systems derived by Murchland is shown to be particularly well suited for implementation in connection with the modularization