Joint optimization of maintenance and spares ordering policy for a use-oriented product-service system with multiple failure modes

The use-oriented product-service system, such as the bike-sharing system and the electric vehicle charging station, has gained wide application in engineering fields. Use-oriented product-service systems are commonly subject to failures of software and hardware. Failed software can be repaired while failures of hardware require the replacement by spares. An innovative joint optimization model of maintenance and spares ordering policy is proposed for a use-oriented product-service system in this work where different types of spares are considered for hardware failure. System effectiveness is maximized by simultaneously considering the incurred costs, system availability, spares availability and the availability of repair engineers. Then, the related reliability probabilistic indices and costs are derived through the continuous time Markov process. To overcome the computational complexity, a greedy search algorithm is applied to obtain a balanced optimal solution for the number of repair engineers and spares inventory policies of different types of parts. Finally, some numerical instances are given to demonstrate the superiority and effectiveness of the proposed joint optimization model.