Scheduling a constrained hybrid flow shop problem by heuristic algorithm

Due to the closeness between theory and industrial practice, the scheduling problem has been investigated by many experts and practitioners. The mode of continuous casting and hot charge rolling in the steel making is one of the important research areas. Limited buffers and due dates of jobs which characterize the problem here investigated. Based on the analysis from a new angle, a hybrid algorithm, which includes heuristic repairing and neighborhood search, is proposed. In the first phase, jobs are processed by problem dependent heuristic rules. Subsequently, two rules are given to reduce the idle time in buffers of jobs and minimizing the cost of tardiness. Finally, the neighborhood search is performed to improve objectives. From the experiments, the affect of two rules to the results are compared and analyzed. The experiments also show the hybrid algorithm is feasible and effective.