Reliability optimization of multi-state systems with two performance sharing groups

Increasing research efforts have been devoted to the reliability analysis of multi-state systems (MSSs) with different performance sharing mechanisms. This paper investigates the reliability optimization problem of an MSS with two performance sharing groups. Such systems consist of multiple components and two common buses. The components connected by the same common bus make up a group and the performance can be shared in the group to meet the demand. Specially, components can be in one group or both. Taking advantage of this property, the components with larger performance and demand are preferentially placed in the overlapping part of two groups since more performance can be shared. The objective is to efficiently derive the optimal configuration policy that maximizes the system reliability. Universal generating function is utilized to develop the reliability evaluation algorithm. Then, stochastic orders are utilized to determine the components to be placed in the overlapping part, which reduces the solution space. Genetic algorithm is applied to find the optimization results in the reduced solution space. Numerical examples validate the effectiveness of the proposed reliability evaluation algorithm. The improved optimization method also outperforms the method without solution space reduction in improving the system reliability.