Nowadays, modern production patterns, such as batch production, have brought new challenges for multi-unit maintenance decision-making. The maintenance scheduling should not only consider individual machine deterioration, but also apply to batch production with variable lot size. An interactive bi-level maintenance strategy is thus proposed in a multi-unit batch production system with degrading machines. In the machine-level scheduling, a multi-attribute model (MAM) is used to obtain maintenance intervals according to individual machine degradation. In the system-level scheduling, a novel production-driven opportunistic maintenance strategy is developed by considering both machine degradation and characteristics of batch production. In this strategy, advance-postpone balancing (APB) utilizes set-up times as opportunities to make real-time schedules for system-level maintenance. The numerical example shows that the proposed MAM–APB methodology can efficiently eliminate unnecessary production breaks, achieve significant cost reduction and overcome complexity of system scheduling. 
Production-driven opportunistic maintenance for batch production based on MAM–APB scheduling