Research On Model And Algorithm Of Related Artifacts Job Shop Scheduling Problem

Unlike traditional manufacturing,the discrete manufacturing industry needs to process parts and assemble them into products.Among them,the discrete processing enterprises focus on the manufacturing of parts,and the discrete assembly enterprises are more focused on the assembly of the workpiece.In the discrete manufacturing enterprise of the type of processing and assembly,processing and assembly are done mainly by themselves,the manufacturing and assembly type discrete manufacturing enterprises are obviously more complex,compared with the first two types of enterprises.Especially in actual production,many workpieces need to be allocated or assembled,because this relationship is ubiquitous in machining assembly discrete manufacturing enterprises,and we put forward the job shop scheduling problem of the related workpieces.First of all,in order to meet the individual demand of discrete manufacturing enterprises,focus on the production of related artifacts job shop scheduling characteristics,this paper discuss the definition and mathematical description of the job shop scheduling problem related to the workpieces.According to the reference standard,parameter definition,objective function and constraint condition of the model,we build a P-R(Partial Relation)graph model that aims at the shortest process cycle,and introduce the building method,the rules of modeling of the P-R graph model and the modeling steps of the formalized language in detail.What more we verify the validity and practicability of the model through some small cases.Secondly,in order to solve the related artifacts job shop scheduling problem,a key node algorithm based on influence rate is proposed.Based on the P-R model,the key processes and key nodes are determined according to the path distribution and critical path of the model,and the influence degree of the process on the total construction period is analyzed based on the influence rate of the process.The paper describe the algorithm steps in detail and make flow charts after all the artifacts have been sorted,if the completion time of the artifacts is not in the delivery period,the selective optimization algorithm is performed,and adjust part of the artifacts so as to ensure all artifacts are completed during delivery time.A case of real data is collected,and the feasibility and effectiveness of the proposed algorithm are verified by an example.Finally,Building MES job planning and scheduling prototype system,this system is in the middle layer between plan level and control level.It is responsible for managing production technology and monitoring real-time information,and monitoring the whole process of production tasks in shop floor.Embedding the key node algorithm based on the impact rate in the job planning and scheduling module.Experiments are carried out using the historical data of an axial flow turbine to verify the effectiveness of the proposed P-R model and the key node algorithm based on the impact rate.