Dynamic rescheduling that simultaneously considers efficiency and stability

Dynamic job shop scheduling is a frequently occurring and highly relevant problem in practice. Previous research suggests that periodic rescheduling improves classical measures of efficiency; however, this strategy has the undesirable effect of compromising stability and this lack of stability can render even the most efficient rescheduling strategy useless on the shop floor. In this research, a rescheduling methodology is proposed that uses multiobjective performance measures that contain both efficiency and stability measures. Schedules are generated at each rescheduling point using a genetic local search algorithm that allows efficiency and stability to be balanced in a way that is appropriate for each situation. The methodology is tested on a simulated job shop to determine the impact of the key parameters on the performance measures.