中文摘要：

研究不同性能指标柔性作业车间调度问题的优化。针对柔性作业车间调度问题的特点，设计基于工序编码和基于机器分配编码的两种交叉和变异算子，并提出一种双层子代产生模式的改进遗传算法应用于该调度问题，以使子代更好地继承父代的优良特征。使用实例测试改进的遗传算法，并与其他遗传算法的测试结果进行比较，所提出算法的有效性得到证实。

英文摘要：

The multi-objective optimization of the flexible job-shop scheduling problem （FJSP） is studied. According to the characteristics of the FJSP, two effective crossover operators and mutation operators are designed for the genetic algorithm. In order to preserve the good characteristics of the previous generation and reduce the disruptive effects of genetic operators, a multistage-based generation alteration model of genetic algorithm is proposed to solve the FJSP. The approach is tested on two instances taken from the literature and compared with other approaches. The computation results validate the effectiveness of the proposed algorithm.