确定需求时上游层面VMI利益分配机制研究

假设外界需求确定,充分考虑实施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订货周期也不一致的现象,建立供需方在传统库存模式与VMI模式下的经济效果模型,得出VMI可使供应链上游层面整体受益的结论。在此基础上,区分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,利用Stackelberg博弈、纳什均衡等理论,构建上游层面VMI模式下各情境的利益分配机制,该机制最终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,达到共赢的目标,同时,还可为如何在价格层面制定激励策略提供理论参考。     

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。     

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。     

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。     

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.     

考虑缺货成本的VMI利益分配

考虑缺货成本,从库存成本角度开展研究,通过对比实施VMI前后供应链库存成本模型,指出VMI短期内供应链收益来源于库存成本变化,且存在责任利益不一致的情况。针对供需双方不同地位,应用价格契约、斯坦科尔博格博弈模型与收益共享契约分别建立了零售商占优与供需双方地位平等情况下的利益分配模型,求解出零售商激励采购价格与收益共享系数的具体值,并采用算例进行分析。     

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。     

零售商占优的VMI利益分配研究

考虑缺货成本与供应链协调水平,从库存成本角度开展研究,引入非求导的数学解析法,对比分析实施VMI前后供应链库存成本模型,指出VMI短期内供应链收益来源于库存成本变化且受到供应链协调性的影响,证明供需双方存在责任利益不一致的情况.在此基础上,应用价格契约与斯坦科尔博格博弈模型建立了零售商占优的利益分配模型,求解出零售商激励采购价格,认为该价格将随供应链协调水平上升而下降,且有可能低于实施之前的采购价格,最后采用算例对该机制的激励效果进行分析,证明可行.     

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。     

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。     

基于VMI的医院供应管理

医院大部分药品及相关用品属于易逝品,针对该类产品的特点,将VMI(Vender Managed Inventory)方法引入到医院供应管理研究中,通过建立两级供应链库存定量模型(即供应商-医院关系模型),比较实施VMI方法前后,医院、供应商以及供应链总库存成本的变化情况.通过定量比较证实,实施VMI方法可以有效降低医院及供应链总库存成本,供应商的库存成本虽有所升高,但是可以通过转移支付方法,使供应商与医院达到利益均衡点,从而降低供应链总库存成本,获得pareto均衡.     

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。     

基于供应链管理的企业库存优化效果模拟与分析

利用供应链管理的思想,通过对供应链上的企业库存进行优化模拟与分析,揭示了供应链内部信息共享、加快信息流动、缩短订货周期、供应商管理库存(VMI)等是影响供应链管理优化效果的核心因素;通过比较应用供应链管理前后企业库存的变化,说明了供应链管理可以有效平抑库存,缩短供货周期,降低企业成本,提高企业核心竞争力。     

Decision support system for vendor managed inventory supply chain: a case study

Vendor-managed inventory (VMI) is a widely used collaborative inventory management policy in which manufacturers manages the inventory of retailers and takes responsibility for making decisions related to the timing and extent of inventory replenishment. VMI partnerships help organisations to reduce demand variability, inventory holding and distribution costs. This study provides empirical evidence that significant economic benefits can be achieved with the use of a genetic algorithm (GA)-based decision support system (DSS) in a VMI supply chain. A two-stage serial supply chain in which retailers and their supplier are operating VMI in an uncertain demand environment is studied. Performance was measured in terms of cost, profit, stockouts and service levels. The results generated from GA-based model were compared to traditional alternatives. The study found that the GA-based approach outperformed traditional methods and its use can be economically justified in small- and medium-sized enterprises (SMEs).     

Vendor-managed inventory with consignment stock agreement for single vendor–single buyer under the emission-trading scheme

This paper presents a joint economic lot size (JELS) model for coordinated inventory replenishment decisions under the vendor-managed inventory (VMI) with consignment stock (CS) agreement and an emission-trading scheme. The paper assumes a single product that flows along a two-level supply chain system, with a single vendor and a single buyer. The total cost of the system is the performance measure, which is the sum of the vendor’s and the buyer’s total costs. The total cost includes the set-up and order costs, inventory holding costs, greenhouse gases (GHG) emissions tax and penalty costs. A mathematical model is proposed to determine: (1) the vendor’s production lot size quantity; (2) the number of shipments sent by the vendor to the buyer in a cycle; and (3) the production rate that minimises the total cost of the supply chain. Some numerical examples are carried out, as well as comparisons with the traditional JELS model for a classic two-level supply chain. Results show that the performance of the system is better when it is operated under a VMI with CS agreement, which is capable of reducing the traditional inventory holding costs and, for some values of given parameters, the GHG emissions tax and penalty costs.     

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.     

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。     

The role of spot market in a decentralised supply chain under random yield

We consider a decentralised supply chain with demand uncertainty, wherein a manufacturer sells a single product that consists of two components to the end consumer through an independent distributor. Assume that one component has a random yield, the manufacturer may rely on the spot market to replenish any shortage components after the random yield is realised. We identify the optimal product order, component production and replenishment decisions under two different situations. One is the traditional arrangement that the distributor decides the product procurement quantity and the manufacturer chooses the production quantity. The other is vendor-managed inventory (VMI) arrangement in which the manufacturer is responsible for both the order and the production decisions. The results show that the role of spot market can effectively offset the negative effects from production yield’s, market demand’s and component spot price’s variances. Consequently, the spot market leads to the cooperation between the manufacturer and the distributor, and improves the channel’s overall performance, in particular under the VMI arrangement when the wholesale price is sufficiently high.