| The inbound logistics of parts and components is the key focus of EMU manufacturing enterprises,and the efficiency and cost of inbound logistics are crucial to the company’s operations.When planning inbound logistics,EMU manufacturing enterprises must not only consider the transportation problems caused by the geographic location of each supplier,but also consider the inventory problems caused by the transportation time interval.The quantity and variety of EMU components are large and diverse.The timely supply of components is critical.Companies must not only pay attention to transportation costs,but also pay attention to inventory costs under just-in-time supply.Only when efficiency and cost are optimized at the same time can corporate goals be met.How to safely,efficiently,and cost-effectively use the limited transportation resources to deliver the EMU parts to the company’s logistics center through a suitable inbound logistics model is the problem to be studied in this thesis.How to formulate transportation routes,calculate the frequency of picking up parts,and how to rent transportation capacity under fluctuating demand are all challenges faced by decision makers.First,determine the research object and research content of this thesis.Searching and sorting out relevant literature around the research content,summarizing the research status,classifying and summarizing the three aspects of EMU parts logistics,Milk-Run,route planning under demand fluctuations,and then determine the research method of this thesis.Secondly,taking Company Z as an example to analyze the current status and characteristics of its EMU parts inbound logistics,clarify that it has problems such as difficult inbound logistics control and management,high inbound logistics costs,and high inventory capital costs,and explore the cause of the problem.In order to solve the existing problems and improve the competitiveness of the enterprise,combining the actual situation of the company to plan the Milk-Run route,constructing the objective function of the transportation cost and the inventory capital holding cost,and adding the stacking constraint to solve the problem through the model.Thirdly,based on the current situation of demand fluctuations,a multi-model Milk-Run model is constructed to optimize the route.Taking the cost of renting a car,the transportation cost,and the holding cost of inventory funds as the optimization objectives,the route sequence and the car use plan under the fluctuation of demand are solved.Finally,on the basis of company Z’s existing data,MATLAB programming software and improved genetic algorithm are used to solve the problem,the path and cost before and after planning are compared and analyzed.The Milk-run mode can reduce the company’s transportation costs and inventory holding costs.,Reduce the average storage time of parts and components,and verify the effectiveness of the model through actual conditionsThere are 27 figures,18 tables,and 65 references in this thesis. |
