Scheduling flexible job shop problem subject to machine breakdown with route changing and right-shift strategies

In this paper, flexible job shop scheduling problem with machine breakdown is of concern. Considering that there is a limitation in improving robust and stable performance of rescheduling with a single strategy, an approach with multi-strategies is proposed to make the scheduling more robust and stable. First, in prescheduling, a new idle time insertion strategy is put forward. In this new policy, idle time equal to repair time is inserted into an appropriate position of each machine according to the machine's breakdown nature. Second, route changing strategy combined with right-shift policy is proposed to keep the rescheduling as stable and robust as possible. In this policy, whether to right shift or route change is dependent on the cost of archiving robustness and stability. Based on the two strategies, new algorithms dealing with idle time insertion, right-shift scheduling, and route changing scheduling are designed. The computational results show the effectiveness of the new strategies and new algorithms compared with other strategies.