A Dynamic Scheduling Method for Flexible Job Shops Considering the Availability of Machining Equipment

Abstract

The invention provides a flexible job shop dynamic scheduling method taking the availability of machining equipment into consideration, belonging to the technical field of shop scheduling. When the availability of machining equipment is decreased to a certain threshold, the machining equipment is preventively maintained, and a pre-scheduling scheme is generated in order to reduce the probability that the machining equipment is abnormal in the machining process; and then, the running status of the equipment is detected in real time in the machining process. When that the status of the equipment is abnormal is detected, whether to take a rightward shifting strategy or to execute a rescheduling strategy is judged by analyzing the influence degree of the duration of the abnormal status on the maximum time of completion. Based on the availability of machining equipment, the machining equipment is preventively maintained by inserting idle time, so the probability that the machining equipment is abnormal is reduced. Meanwhile, by detecting the running status of equipment in real time, the rescheduling response ability when there is an abnormality is improved, and the stability and timeliness of job shop dynamic scheduling are improved.

Description

technical field [0001] The invention belongs to the field of workshop scheduling, and in particular relates to a dynamic scheduling method for a flexible job workshop, which is used for scheduling optimization and management of the workshop production process. Background technique [0002] As a workshop-level manufacturing system, the job shop is the main production activity center of machining and manufacturing enterprises, the main site of resource flow and production process, and the key to manufacturing enterprises. Therefore, the optimal operation technology of the job shop has always been a hot research field. How to reduce the processing time, improve the processing efficiency and reduce the processing cost are the main issues it pays attention to. The typical job shop scheduling problem is a kind of combinatorial optimization problem. [0003] In the traditional workshop scheduling model, it is assumed that the resources required for process processing are not flexib...

AI Technical Summary

Problems solved by technology

[0006] In addition, most existing studies assume that the relevant parameters of the job shop are deterministic and known, but in the actual production process of the manufacturing system, there will be random uncertain factors that affect the normal operation of the scheduling

For example, the processing time is uncertain, the status of machining equipment is abnormal, and the workpiece arrives randomly, etc., the scheduling method under the ideal state cannot be directly applied to the production process with uncertain factors

Images