A Computer Program for Approximating System Reliability

A computer program, which provides bounds for system reliability, is described. The algorithms are based on the concepts of success paths and cut sets. A listing of the elements in the system, their predecessors, and the probability of successful operation of each element are the inputs. The outputs are the success paths, the cut sets, and a series of upper and lower reliability bounds; these bounds converge to the reliability which would be calculated if all the terms in the model were evaluated. The algorithm for determining the cuts from the success paths is based on Boolean logic and is relatively simple to understand. Two examples are described, one of which is very simple and the computation can be done by hand, and a second for which there are 55 success paths and 10 cuts and thus machine computation is desirable.