A new model for the reliability-redundancy allocation problem with the mixed redundancy strategy

Abstract

In this paper, the reliability-redundancy allocation problem with the mixed redundancy strategy is revisited to develop a new model that can be beneficially exploited to estimate exact reliability values. The model is capable of not only optimally calculating reliability values in a very short time but also choosing the best strategy for each subsystem from among active, standby, and mixed strategies. In previous studies, reliability calculation for the mixed strategy had been accomplished using a lower bound formulation that was sophisticated, time-consuming, and approximate. The proposed model is developed based on a continuous-time Markov chain model. It is applied to three famous benchmark tests that are subsequently solved using a powerful evolutionary algorithm called the water cycle algorithm. Computational results confirm the robustness and superiority of this new model over previous ones in calculating reliability. Besides, the proposed algorithm outperforms the previous ones in finding good results.