侧向转运是库存共享的一种方式,一方面会减少库存成本,另一方面又会因转运而增加运输成本,针对这一问题考虑不同时间窗Wk的服务水平产生的服务水平的分级,构建三级分销网络中基于库存共享与时间服务水平限制的批量订货模型,分销网络模型中包含一个制造商、一个RDC、m个DC、n个客户。其中客户的需求相互独立且服从泊松分布,DC的订货提前期服从指数分布。首先,建立了基于时间服务水平限制的分销网络系统总成本最小化模型,并将再购点、订购批量等库存参数作为同时作为决策变量,以达到三级备件分销网络的成本优化;其次,根据问题和模型的特点对所建的模型开发了基于采用贪婪增加算法的求解思想求解问题,以便给管理者提供决策参考并通过降低利润的方式增加效益和资源利用率;最后,通过中航材集团推行的“航材共享”项目作为算例分析,将三个分销区域与机场群组成的备件分销系统进行建模分析,验证了本文模型的有效性,成本优化的显著性。研究结果表明,三级分销网络中,RDC采用连续盘点的(Q,R)补货策略、DC采用(Q,R,H)的补货策略时系统总成本与普遍采用的定期盘点策略和连续盘点中的One-for-One订货策略成本相比,DC之间的库存共享策略能有效降低整个系统的成本,例如,在案例研究中发现成本降低约为30%。
Lateral transshipment is an effective and paradoxical way in sharing inventory process. On the one hand, the total cost of inventory system can be reduced and on the other hand, the transportation costs will be increased in transit. The time window Wk, which helps to identify different service classes for consumer groups through diversified level of service,is presented to build the three-echelon spare parts logistics network with inventory sharing and time service level limit. The distribution network model with the input of n groups of customers contains a manufacturer, a RDC and the DC parameter——the default value is m. In the queuing system model, customer's requirements are independent of each other and obey the Poisson distribution; order lead time of DC obeys Exponential distribution, so as to standardize the actual complex problems. The detailed research idea of dissertation is as following:(1) a distribution network system is established considering the constraints of service level and inventory pooling so that the total cost can be reduced compared with the traditional way, and then some of inventory parameters such as repurchase dots, order quantity and etc. are considered as the decision-making factors at the same time in the three layers of tree network distribution system model in order to optimize the complex system cost of the local and global; (2) in view of the features of the problems derived from the production and the model described in the first part,a new improve algorithm is designed, based on the idea of greedy algorithm to solve the lateral transshipments model problem and get the optimal solution of decision variables in order to provide reference to managers and increase profits and resources utilization by reducing the cost; (3) through an analysis on the sharing project of the company named China Aviation Supplies Holding Company(CASC), the data from Southwest regions (DC1), northwest regions (DC2) and northeast regions (DC3) of the company is used to construct and validate the model so that the rationality of the model and the feasibility of the algorithm can be seen in the three-stage spare parts distribution system of the paper. Research results indicate that in the tertiary distribution network, when the RDC adopt continuous review (Q, R) replenishment strategy and DC with (Q, R, H), the replenishment strategy of system make total cost lower than the continuous review inventory strategy such as One-for-One ordering strategy which is widely adopted strategies of inventory check in production. inventory sharing strategy between DC can effectively reduce the cost of the whole system and in the case study costs is cut about 30%.
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