Joint optimization of cooperative maintenance and inventory control for multiple k-out-of-n: F systems considering component interchange and shared spare parts

In recent years, many studies have confirmed that the joint optimization of maintenance and spare parts inventory can better balance system availability and cost. However, existing research is usually limited to maintenance strategies for single system. To bridge this gap, this paper investigates the joint optimization of cooperative maintenance and spare parts inventory control for multiple identical k-out-of-n: F system composed of unrepairable components under different states. To solve this problem, under the management mode of spare sparts inventory shared, the maintenance method of component interchange between systems is proposed, and the component degradation model and multi-system joint optimization model are established. The state of the system is determined by regular inspection, and according to the states of each system and inventory level, the optimal cooperative maintenance strategy and spare parts ordering strategy are decided by Markov Decision Process (MDP) and dynamic programming theory. Finally, a numerical study on two 2-out-of-3: F systems is conducted, and the sensitivity analysis of the inspection interval length, the system downtime cost, the unit inventory holding cost and the minimum system reliability is carried out, which can prove the validity of the model and solution method.