Optimal cost-effective design of complex systems

Reliable system designs are important to minimizing system failures and associated losses. System reliability can be improved by using sparing redundancy. Spares can be kept in hot or cold standby mode. Although the reliability of a system increases with the addition of spares, the cost of the system also increases due to the number of redundant components added to the system. Thus, it is desirable to derive a cost-effective solution that strikes a balance between the system failure cost and the cost of spares in the system. In this paper, we consider that the system consists of several subsystems, which are arranged in a network con guration pound. Each subsystem requires a minimum number of identical components to perform its functions. The additional spare components in each subsystem can be kept in cold or hot standby mode. The objective is to nd pound the optimal number of components in each subsystem that minimizes the overall cost associated with the system. As a part of the algorithm, we provide bounds for optimal spares quantity for each subsystem. The bounds are used to reduce the search space and hence improve the ef ciency pound of the optimization algorithm.