Cost-optimization heuristic algorithm in safety engineering

A hierarchical fault tree, on the basis of the system branch tree, is considered. Each basic element at the bottom level may relate to a set of possible primary failures, some of which, in turn, may have an essential influence on critical failures at the top level. We suggest several optimization models with cost objectives which enable diminishing the probability of a critical failure via reducing the probabilities of primary failures to occur. The objective to be minimized is the entire cost of required technical alterations, subject to the pregiven upper permissible level of the critical failure's probability.