Optimization limits in improving system reliability

A computationally simple approach for reliability-redundancy optimization problems is proposed. It is compared by means of a simulation study with the other two existing approaches: (1) the LMBB method, which incorporates the Lagrange multiplier technique in conjunction with the Kuhn-Tucker condition and the branch-and-bound method, and (2) sequential search techniques in combination with heuristic redundancy allocation methods, including an extension of combinations of four heuristics and two search techniques. Using 100 sets of randomly generated test problems with nonlinear constraints for both series systems and a complex system, the authors measured and evaluated the performance of these approaches in terms of optimality rate, error rate, and execution time. In general, the author´s method requires considerably less computer time to obtain results comparable to those of the other methods, and it has a low degree of programming difficulty