A computation method for evaluating importance-measures of gates in a fault tree

This paper extends the Birnbaum importance measure for a basic-event level to a gate-event level. In a fault tree when statistical dependency between gate events exists. An explicit formula is given for gate reliability importance (GR-Imp), and shows how it can compute GR-Imp by using a conventional fault-tree algorithm. The computational algorithm for GR-Imp is given along with numerical results for illustrative examples.