A multi -objective scheduling decision making model for the flexible job shop

Multi-objective scheduling optimization approach often presents the scheduling decision makers a set of Pareto solutions, which is hard to select the most satisfactory one of them, especially in the flexible job shop. Therefore, a multi-stage model for the multi-objective flexible job shop scheduling problem was proposed. Firstly, the two stages model which was named the optimizing phase and the selecting phase respectively was set up. In the first phase, a set of Pareto solutions were obtained with the multi-objective genetic algorithm, including some feasible solutions for the scheduling problem. In the second phase, a multi-objective decision making method was used to select the best solution. Secondly, the analytic hierarchy process method integrated with the fuzzy evaluation for the second phase was put forward in detail. Finally, a practical problem encountered by a flexible job shop manager was solved with the proposed model. The running results show that the model can solve the multi-objective flexible job shop scheduling problem effectively and efficiently.