Optimal allocation of interchangeable components in a series-parallel system

This paper extends the work of El-Neweihi, Proschan, Sethuraman (1986) to maximize the reliability of a series-parallel system through optimal allocation of interchangeable components. It provides a practical procedure for the reliability optimization problem which is shown to be NP complete. Based on an observation that the reliability of series-parallel system increases with the homogeneity among the cutset hazards, an approximate linear programming model is developed in which the objective is to minimize the mean deviation of the cut-set hazards. An algorithm is provided to improve further the resulting allocation. The numerical investigation on this heuristic approach and its application to a large problem have yielded encouraging results.