Abstract: In this paper, seven effective heuristic methods of sequencing jobs are compared and evaluated using simulation method, and an optimising structure is proposed. Then these heuristic methods are improved by the optimizing structure, PLSP-a software package to solve the problem of sequencing jobs is built.PLSP has been used to sequence the jobs on five GT production lines in Qian Shao Machinery Factory, the results are proved to be satisfactory.