Modeling And Optimization Of Vehicle Routing Problem In Mixed-model Assembly Workshop

With the increasingly fierce market competition, customer demands become morediverse, enterprises need to reduce production costs and to enhance the competitiveness ofproducts at the same time. In this situation，mixed mode of production has been applied,while improving the implementation mode and efficiency of material distribution is the keyfactor to enhance the manufacturing effect and response ability to the market changes in flowmanufacturing enterprises. Vehicle Routing Problem (VRP) is one of the core problems oflogistics distribution vehicle routing problem. In this thesis, the mixed model assemblyworkshop environment is taken as the research object, and the main research contents are asfollows：Based on the characteristics of material demands in mixed-model assembly workshop,the thesis analyzes the changes of optimization objectives and constraints of VRP in thisapplication environment. Meanwhile, the modeling characteristic of VRP of mixed modelassembly workshop is discussed.According to the physical constraints in assembly shop, the problem constraints areimproved. This thesis constructs the mathematic model of VRP based on constraints of roadnetwork. According to this model, the large neighborhood search algorithm is improved, thecross station to delete a node set is built, and the model is optimized and verified withgeneral algorithms and instance data.Then, according to the JIT mixed-model assembly workshop on material delivery timerequirements, further improvements based on road network constrained model have beendone. This thesis constructs the optimization model of vehicle routing problem based on timesatisfaction. The thesis has also introduced the principle of small world optimizationalgorithm, put forward the join operator of the algorithm, and improved the algorithm based on the core path length. The effect of different parameters on the results of the optimizationmodel is discussed as a reference to the application of the time satisfaction model.Finally, combining with a practical application, the thesis has completed the design andapplication of the material optimization dispatching module in manufacturing executionsystem, which eliminated the abnormal line stop because of material shortage, shorten theproduction cycle and effectively improved the accuracy of enterprise’s material delivery.