Multicriteria optimization for combined reliability and redundancy allocation in systems employing mixed redundancies

The present paper provides a new mathematical formulation of a combined reliability and redundancy allocation involving multiple objective functions in the reliability design of a system employing mixed type of redundancy. The paper proposes an easily computerizable procedure for solving a variety of design problems. The proposed solution technique is a combination of the direct search technique [9,10] and a random search procedure for optimizing redundancy and reliability at the same time at each subsystem and uses multicriteria optimization procedure based on min-max approach [11,12] for obtaining Pareto optimal solutions. The procedure is illustrated through several examples. A general computer code, called ESMOP (Efficient Search Multi-Objective Programming), for the use on IBM compatible PCs has also been developed. The code takes into account all kinds of redundancies including multiple discrete choices for component reliabilities, and a wide variety of resource coefficients and constraint functions.