供应链上游层面VMI模式的利益分配机制

选取供应链上游层面VMI模式为研究对象,考虑实施VMI后,订货主动权的转移导致订货策略的变化,以及制造商对各零部件需求速率的不同导致其对各零部件的订货周期也不一致的情况,通过建立经济效果模型,探讨上游层面VMI对供应链整体利益的影响.在此基础上,根据供应商与制造商在合作中经常出现的3种情境——平等、供应商占优、制造商占优,建立VM1模式下不同情境的利益分配机制.该机制最终可体现在供应商所售产品的重新定价上,此定价既能弥补供应商因管理制造商库存而增加的成本,又可使制造商的利润得到保障,达到共赢的目的,为上游层面VMI模式的顺利推广提供理论依据.     

供应链上游段VMI模式的共赢条件

选取上游层面VMI模式各参与者为研究对象.考虑实施上游层面VMI模式后,订货(配送)主动权的转移导致订货(配送)策略的不同,以及制造商对各零部件需求速率的不同导致其对各零部件的订货周期也不一致的情况.通过建立数学模型,对实施上游层面VMI模式前后各企业的经济效益进行比较,探讨实施VMI且制造商销售价格不变时,各供应商是否存在合理的销售价格涨幅区间,该区间的价格既能弥补供应商因管理制造商零部件库存多消耗的成本,也能使各制造商和供应商的经济效益都有所提高,实现共赢,为各企业更加长久的合作提供理论依据.     

随机需求时上游段VMI模式共赢条件

考虑实施上游段VMI模式后,订货（配送）主动权的转移导致订货（配送）策略的不同,以及制造商对各零部件需求速率的不同导致其对各零部件的订货周期也不一致的情况。假设外界需求随机,通过建立模型,结合模拟仿真,对实施上游段VMI模式前后各企业的经济效益进行比较,探讨实施VMI且制造商销售价格不变时,供应商是否存在合理的销售价格涨幅区间。该区间的价格既能弥补供应商因管理制造商零部件库存多消耗的成本,也能使制造商和供应商的经济效益都有所提高,实现共赢,为上游段VMI模式的推广提供理论依据。     

VMI进行卡尔多-希克斯改进必要性研究

考虑需求放大、订货及库存成本变动等因素,构建完全竞争市场条件下的VMI模型,进行解析分析和仿真求解,证实了供应商管理库存策略进行卡尔多-希克斯改进的必要性。运用灵敏度分析,确定了影响上游企业参与VMI的重要因素,并得出越是优秀的上游企业参与VMI的积极性反而较低的结论。     

独立随机需求下共享剩余库存的双渠道订货与定价模型

考虑由一个零售商经营的具有依赖于价格的独立随机需求的双渠道,在销售季节末当一渠道缺货时可分享另一渠道的剩余库存,研究了两个渠道各自的订货与定价决策问题,分别建立了不共享剩余库存和共享剩余库存时的双渠道纳什博弈模型。运用博弈论、最优化理论求解各种模型下存在纳什均衡解的条件、最优订货数量和最优定价。同时研究结论表明,针对价格或订货数量不易改变的产品,零售商实施共享剩余库存后应减少两渠道的订货数量或增加定价。通过数值分析验证上述模型、结论的有效性,并得到了零售商实施共享库存策略相对是占优策略的结论。     

短缺量拖后率与价格折扣相关变质品VMI模型

考虑短缺量拖后率与订货商给予顾客的价格折扣正线性相关,提出一种需求指数时变的变质物品供应商管理库存模型,研究了供应链最优库存策略。数值仿真和主要参数灵敏度分析表明,订货商在缺货期间向顾客提供价格折扣有利于降低丢单损失和系统库存总成本;当需求增长因子变化时,VMI系统应保持库存控制策略不变;当变质系数和拖后率上限变大时,VMI系统则应保持订货商补货次数和价格折扣不变,同时适当降低订货商服务水平。     

分散协调VMI&TPL模式下的补货决策

提出分散协调供应商管理库存(VMI)与第三方物流(TPL)集成供应链管理模式。与传统VMI不同,该模式下的供应商拥有库存决策权,但将物流具体作业外包给TPL。从供应商角度出发探讨了该模式下的补货决策问题。本模型引入供应商与制造商之间的需求信息共享,同时考虑供应商与TPL之间的运费契约,运费是与补货量有关的分段函数。供应商根据制造商滚动计划期内的需求量、运费契约以及制造商线边仓库的存储能力等进行补货决策。通过将模型转化为动态网络规划问题,分析了模型的计算复杂性。由于该模型问题是NPC问题,给出了模型的模拟退火遗传算法。算例验证了模拟退火遗传算法解决该问题的有效性。     

产能与需求不确定下基于MOI和VMI的供应链比较研究

为分析供应链运作机制对降低产能不确定和需求不确定的影响,对比研究了MOI和VMI两种供应链运作模式下单关键零部件供应商-单制造商组成的两级供应链系统。MOI模式下,制造商负责产品的库存决策,并承担相应的零部件库存成本和缺货成本;VMI模式下,供应商负责产品的库存决策和额外产能储备决策,并承担相应的零部件库存成本和过剩能力闲置成本。给出了供应链的最优解及期望利润;为进一步讨论供应链管理模式对提升供应链运作效率的管理意义,分析了随机需求、随机产能及批发价格对两种模式的影响。     

三级供应链VMI收益及Shapley值分配仿真研究

考虑需求放大、订货及库存成本变动等因素,构建三级供应链在分散式、上游段、下游段及集成式VMI四种情况下的收益模型,通过仿真定量说明VMI对于上、下游企业收益及风险的不同影响,并得出结论:下游段VMI实施后,集成式VMI将成为激励相容,而上游段VMI的实施将阻碍集成式VMI的实现,证实了VMI的实施顺序对供应链管理的重要影响。后采用Shapley值法分析各企业特征函数,确定Shapley值计算公式,进行收益分配,解决了收益与风险不对等所导致的VMI合作不稳定问题,促进集成式VMI的形成与长期稳定。     

具有激励机制的VMI系统Stackelberg博弈

一般供应商管理库存(VMI)模型没有考虑激励机制问题,而订货商的激励政策对供应商管理库存的成本分担有很大影响。考虑订货商对管理库存的供应商采取一定的激励政策,建立了一个生产型供应商和一个销售型订货商构成的二级供应链VMI系统的Stackelberg博弈模型。通过博弈最优解、算例和主要参数的灵敏度分析,表明:激励机制对供应商的努力程度和双方利润有较大影响,激励政策与双方库存成本的分担有密切关系。     

单供应商面对具有多个销售点的零售商时的VMI模型研究

在供应商管理用户库存（VMI）环境中,当面临的具体条件不同时,供应商和零售商的利润分配是不同的,论述了当一个供应商面对具有多个销售点的零售商时的VMI模型,此时供应商负责库存决策,他可以在各个销售点之间转运（Transshipment）库存.建立了供应商和零售商的一个Stackelberg博弈,零售商作为领导者是通过决定销售价格来体现的.结果显示最终供应商和零售商可以达到一个子博弈精练纳什均衡,零售商在该模式下获得了很大的利润份额.给出了一个算例计算了均衡时的库存量和销售价格.     

供应链管理中VMI系统的研究

通过分析VMI和RMI在概念原理上的本质差异,讨论了VMI在管理思想、决策方式、预测体系、补货模式、延迟策略方面的优越性和先进性。在此基础上,详细描述了VMI工作流程中的八个关键环节,并结合实际指出实施VMI的步骤和注意事项,最后总结了VMI在实践中给供应商、零售商以及供应链整体带来的收益和竞争优势。     

An analysis of the general benefits of a centralised VMI system based on the EOQ model

Within a vendor-managed inventory (VMI) agreement, the upstream supply chain member (the vendor) takes responsibility for managing the inventory of the downstream member (the customer) within specific levels previously agreed upon without the need of orders from the customer side to be placed. Therefore, the vendor can focus on optimising production efficiency and capacity planning, while the customer has to improve forecast accuracy. This paper analyses the benefits a VMI agreement could bring for a one-supplier, multiple-customer case through analysing two cases: a supply chain managed in a traditional manner and VMI when both the vendor and the customers belong to the same organisation. The analysis is based on the economic ordering quantity (EOQ) formula and its related total cost, and the novelty is captured by evaluating one vendor, multiple buyers, and multiple product situations. The modelling is done so as to capture the needs and factors which occur within the pharmaceutical industry and a numerical application will be executed with data from one of the main leaders within the pharmaceutical field.     

部分短缺量拖后且考虑最终产品变质的VMI模型

在无短缺量拖后或短缺量完全拖后的VMI模型基础上,进一步考虑缺货期间出现短缺量部分拖后的情况,建立了包括一个供应商和多个订货商、从原材料到产成品且最终产品出现变质的供应商管理库存（VMI,Vendor-Managed Inventory）模型,给出了数值算例和主要参数的灵敏度分析,结果表明顾客服务水平、丢单系数及最终产品变质率对供应链各成员的单项成本及集成总成本均有不同程度的影响,为VMI库存系统的管理决策提供了理论依据。     

跨境VMI供货模式下生产-库存联合优化研究

研究基于跨境VMI(vendor managed inventory)供货模式下的生产-库存联合优化问题。以一个实际案例企业作为应用背景,比较了VMI供货模式和传统的供货模式在海运和空运2种运输方式下的不同特点及其对决策的影响。研究结果表明,对于案例企业而言,采用VMI供货模式的库存管理是可行的,考虑目前公司采用2种可选的运输模式,选择海运的总成本最低。通过对资金费用率、库存费用比率和缺货费用率进行灵敏度分析,探讨了不同环境变量对最优决策的影响。研究结果对跨境供应链多国生产型企业改善跨境物资采购和生产-库存决策有一定参考价值。     

Vendor-managed inventory: a review based on dimensions

Vendor-managed inventory (VMI) represents the methodology through which the upstream stage of a supply chain (vendor) takes responsibility for managing the inventories at the downstream stage (customer) based on previously agreed limits. VMI is another method by which supply chains can be managed, and, owing to centralised decision-making and constant information sharing, the benefits are much higher than in traditional supply chain case. However, there exists a lack of research that identifies the dimensions of VMI, benefits of VMI, methods, and levels used in the VMI environment. The focus of this paper is to explore the existing literature on VMI, to categorise it according to the criteria evaluated, and to present a systematic review. In this study, we have classified the review into three categories such as dimension-based, methodology-based, and level-based. From the thorough literature review, we have identified six dimensions of VMI: namely, inventory, transportation, manufacturing, general benefits, coordination/collaboration, and information sharing. In addition, there are, three methodological classifications: modelling, simulation, and case studies. Finally, we will consider the level-based classification. Based on the review, several recommendations that improve the performance of VMI are presented.     

Vendor-managed inventory and the effect of channel power

We analyze decentralized supply chains that follow general continuous review (Q, R) inventory policies subject to vendor-managed inventory agreements where the supplier chooses the order quantity Q, and the retailer chooses the reorder point R. Within the VMI scenario, we explore the effect of divisions of channel power on supply chain and individual agent performance by examining different game theoretic models. Optimal policies and analytical results, including existence and uniqueness proofs for equilibrium solutions under VMI, are derived. Numerical results are provided to compare the effectiveness of VMI and to analyze different channel power relationships under a variety of environmental conditions. We find that VMI can result in considerable supply chain savings over traditional relationships and that the relative division of channel power can significantly effect the performance of VMI. Interestingly, we find that the greatest system benefits from VMI arise in asymmetric channel power relationships, but that individual agents lack the incentive to assume a leadership role.     

Calculating the benefits of vendor managed inventory in a manufacturer-retailer system

Firms such as Wal-Mart and Campbell's Soup have successfully implemented vendor managed inventory (VMI). Articles in the trade press and academic literature often begin with the premise that VMI is ‘beneficial’; but beneficial to which party and under what conditions? We consider in this paper a vendor V that manufactures a particular product at a unique location. That item is sold to a single retailer, the customer C. Three cases are treated in detail: independent decision making (no agreement between the parties); VMI, whereby the supplier V initiates orders on behalf of C; and central decision making (both vendor and customer are controlled by the same corporate entity). Values of some cost parameters may vary between the three cases and each case may cause a different actor to be responsible for particular expenses. Under a constant demand rate, optimal solutions are obtained analytically for the customer's order quantity, the vendor's production quantity, hence the parties’ individual and total costs in the three cases. Inequalities are obtained to delineate those situations in which VMI is beneficial.     

关于VMI下供求双方的利润变化的研究

针对传统库存管理系统存在的牛鞭效应,分析了一种新的库存管理方法:供应商管理库存(VMI).通过定量的方法证明了在VMI下供求双方的库存成本及其利润变化的情况.结果表明:在实施VMI的情况下,购买商的利润总是能够提高,而供应商短期内利润会下降,若长期实施VMI其利润在很大程度上也能够提高.通过实例验证了该结论的正确性.