Job shop scheduling optimization method with sufficient necessary condition neighborhood structure

Abstract

The invention belongs to the technical field related to workshop scheduling, and discloses a job shop scheduling optimization method with a sufficient necessary condition neighborhood structure. The method comprises the following steps: obtaining a scheduled critical path according to a current solution of a job shop scheduling problem, and adjusting the processing sequence of procedures in a critical path block according to sufficient necessary conditions to obtain multiple different processing sequences; and calculating the total processing time of each processing sequence, and taking the processing sequence with the shortest total processing time as the current scheduling sequence. The sufficient necessary conditions are as follows: (1) a path from js (u) to v does not exist, and a neighborhood solution generated by processing after u moves to v is a sufficient necessary condition of a feasible solution; and (2) a path from u to jp (v) does not exist and is a sufficient necessary condition that a neighborhood solution generated by processing before v moves to u is a feasible solution. By means of the invention, when the job shop scheduling problem is solved, the solving qualityis effectively improved, and the solving time is shortened.

Description

[0001] technology neighborhood [0002] The invention belongs to the technical field related to job shop scheduling, and more specifically relates to a job shop scheduling optimization method with a sufficient and necessary condition neighborhood structure. Background technique [0003] The workshop scheduling problem refers to the rational allocation of production resources to improve production efficiency and reduce production costs. The job shop scheduling problem (job-shop scheduling problem, JSP) is a classic shop scheduling problem, which is described as having n workpieces, and each workpiece has m processes that need to be processed on m different machines. The sequence of the machines that flow through during the processing is different, and it is necessary to arrange the processing sequence and processing time of the workpieces on each machine so that certain indicators can be optimized. [0004] JSP is an NP-hard problem. For small-scale problems, exact solutions c...

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Problems solved by technology

For JSP, the neighborhood structure based on the critical path is mostly used. The critical path refers to the longest path from the beginning of processing to the end of all workpiece processing. Now there are three commonly used neighborhood structures based on the critical path, which are named N5 , N6, N7, Nowicki et al. (Nowicki, E., & Smutnicki, C. (1996). A fast taboo search algorithm for the job shop problem. Management Science, 42(6), 797-813.) proposed the N5 neighborhood structure , Balas et al. (Balas E, Vazacopoulos A.Guided local search with shifting bottleneck for job shop scheduling[J].Management science, 1998,44(2):262-275.) proposed N6 neighborhood structure, Zhang et al. (Zhang C Y, Li P G, Guan Z L, et al.A tabu search algorithm with a new neighborhood structure for the job shop scheduling problem[J].Computers&Operations Research,2007,34(11):3229-3242.) proposed a N7 neighborhood structure, the problems in the above methods are: the number of neighborhood solutions obtained is limited, the search time is long and the accuracy is low

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