Condition-based maintenance for multi-component systems using proportional hazards model

Focus on the practical problem that the limited spare resources are not always available for equipment maintenance, a joint optimization model of condition-based maintenance (CBM) and spare ordering policy is established for multi-component systems using proportional hazards model (PHM). Every component in operation is subject to a condition monitoring program. Maintenance decision depends on the remaining useful life (RUL) estimation obtained through PHM based on the condition information. Part of the faulty items can be restored to as good as new after maintenance, and the continuous review (R, Q) inventory policy is adopted, where R is the reorder level and Q is order quantity. The cost evaluation of the proposed CBM model may be complex and difficult for a multi-component system. The Monte Carlo simulation and particle swarm optimization (PSO) are utilized, in order to estimate the maintenance cost rate and minimize long-run cost rate with meeting the availability demand. Through numerical example, the correctness and rationality of the model are proved.