A fatigue-conscious dual resource constrained flexible job shop scheduling problem by enhanced NSGA-II: An application from casting workshop

Dual resource constrained flexible job shop scheduling problem (DRCFJSP) becomes a hot research topic in recent years. However, worker fatigue is barely considered in DRCFJSP, which will result in unsuitable task assignments for workers and bring about negative effects such as muscle fatigue and cognitive confusion. To this end, a fatigue-conscious DRCFJSP is proposed in this paper, aiming at simultaneously relieving fatigue and promoting productivity by joint scheduling of machines and workers. A multi-objective optimization model is constructed to minimize the maximum worker fatigue and makespan. Furthermore, an enhanced NSGA-II (ENSGA) is developed in this paper to cope with the proposed problem. In the ENSGA, four dispatch rules are designed to generate high-quality solutions at the initialization stage. Two neighborhood structures based on a novel method of defining the critical path are designed to strengthen the ability of local search. Finally, with the comprehensive experiments on extensive test instances and a case study from real-world casting workshop, the effectiveness of proposed ENSGA for solving the fatigue-conscious DRCFJSP is verified, and the significance of the proposed joint scheduling approach is elucidated. This work renders the decision-maker practical and effective scheduling with fatigue-conscious for the machine and worker constrained flexible manufacturing system. •A novel multi-objective fatigue-conscious DRCFJSP is investigated.•Heterogeneities of machines and workers are included in fatigue-recovery model.•An effective ENSGA is designed for solving fatigue-conscious DRCFJSP.•Significance of the proposed joint scheduling approach is validated.•A case study in real-world casting workshop is presented.