Abstract: Heat treatment is the bottleneck of the mould manufacturing process,and will have a significant impact for the entire mould of the delivery time and manufacturing costs.The production scheduling of the heat treatment plant has the characteristics of batch dispatching.In the two-stage flexible flowshop,subcontracting is considered.The production plan of heat treatment workshop is divided into three levels:periodic rolling plan,quenching stage machining plan and tempering stage machining plan.With the scheduling objective of minimizing the manufacturing cost,algorithms are proposed for these three stages,respectively.An extensive simulation study is conducted to verify the effectiveness of the proposed strategies.The experimental results show that the manufacturing cost of the setting minimum waiting jobs rule strategy is obviously higher than the other three strategies.Without considering subcontracting,the scheduling strategy is slightly better than the setting maximum waiting time rule strategy,and the performance of scheduling strategies with considering subcontracting is the best among the four strategies.

Key words: batch scheduling, mould, heat-treatment, flow-shop