| With the rapid development of industrial technology and the steadily rising demand for automobiles,information,automation and intelligent technology continue to energize the automobile manufacturing industry.In order to reduce costs and improve efficiency,Automakers are more likely choose to learn "Toyota-style" lean production,and introduce milk-run to the parts supply logistics to achieve JIT production as much as possible.However,the traditional milk-run mode is difficult to exert the greater efficiency of the idea of milk-run.Therefore,aimed at how to further explore the problem of milk-run optimization space.this thesis proposes to introduce the secondary supplier into the milkrun mode of the supply logistics system,and how to further explore the problem of loop picking optimization space.And the mathematical model aiming at the optimal cost is established.The hybrid heuristic algorithm is designed to research the characteristics and effects of the milk-run extension model,and the superiority of the new model is verified.The secondary suppliers,direct suppliers and distribution centers(manufacturing sites)in the supply logistics are taken as the research object in this thesis.With the minimum cost as the optimization goal,the milk-run extended vehicle path model is established under the constraints of inventory and delivery order.The model belongs to a variant of a combination of CFR and VRPSPD.The model has the characteristics of inventory constraints,simultaneous delivery,path priority and multi-frequency transportation,which is closer to the actual supply transportation.Furthermore,for the newly proposed model,a hybrid algorithm combining genetic and simulated annealing features is constructed for the proposed model in this thesis,and numerical simulation is used to verify the reliability and effectiveness of the hybrid algorithm,and to explore the inventory constraints and logistics costs(the sum of transportation costs and inventory costs)under the new model.The relationship shows that,similar to the standard CFR,there is a negative correlation between inventory limits and logistics costs.In addition,the hybrid algorithm designed is applied to the actual data of an automobile manufacturing enterprise.The results of manual scheduling,standard CFR results,and new model results are compared to analyze the characteristics of the new model in some aspects.The model and algorithm provide a new idea and new method for the automobile manufacturing enterprise to implement the milk-run mode,and provide a valuable perspective for other companies that want to try milk-run at the same time. |
