Research On Modeling And Optimization Of The Automotive Service Spare Parts Multi-echelon Inventory

With the increasingly fierce marketing competition, the sales profits of theautomotive vehicle continue to decline but the sales profits of the service spareparts is increasing. The service spare parts logistics as the third profit source isseriously concerned while the spare parts inventory is an important part of the spareparts logistics. The reasonable control of service spare parts inventory guaranteesthe effective supply of the spare parts because the excess inventory takes up muchliquidity and the shortage of the inventory can not meet the customers’ needs.In this paper, firstly, we introduce the theory of the inventory control and theadaptive genetic algorithm, based on these, the concept, needs and supply of theautomotive service spare parts in accordance with the characteristics of theautomotive industry is introduced. The status of the inventory management isanalyzed from the distribution way of the automotive service spare parts and wedescribes the problems of the inventory management from some parts such as theclassification of the spare parts, the control of the inventory and the bullwhip effectin the supply chain of the spare parts inventory. Secondly, this paper investigatesthe two-echelon inventory strategy of automotive service spare parts in thenon-repairable and the repairable automotive service spare parts. For the inventoryquestion of non-repairable spare parts, we expand the multiple regional distributioncenters and multiple automotive4S stores based on a two-echelon non-repairableautomotive service parts inventory system that consists of single center warehouse.A mathematical model with the objective of minimizing the total annual inventoryinvestment subject to constraints on the annual budget, average annual orderfrequency and expected number of backorders is formulated. For the inventoryquestion of repairable spare parts, this paper considers multiple regionalmaintenance centers and multiple automotive4S stores based on a two-echelonrepairable automotive service parts METRIC model. A mathematical model withthe objective of minimizing the expected number of backorders subject toconstraints on the annual budget is formulated. An adaptive genetic algorithm isused to solve the model as the two types inventory model contains so muchUncertainties and Complex calculations. Finally, we design the fitness function ofthe algorithm, crossover and mutation operators to solve the model by Matlab.A numerical example was designed to show the effectiveness of the non-repairable and repairable spare parts two-echelon inventory model,respectively. The calculation results of the numerical examples indicate that theinventory model of non-repairable spare parts can reduce some inventory costs andthe inventory costs also reduce when the annual budget of the regional distributioncenters increases. The inventory model of repairable spare parts can reduce theexpected number of backorders and raise the service level, simultaneously theexpected number of backorders reduces when the annual budget of the regionalmaintenance centers increases at a certain step. The results of this paper canprovide a theoretical approach to the inventory optimization of the automotiveservice spare parts and some reasonable references to the inventory management ofthe automotive service spare parts.