可控提前期下基于交易信用契约的供应链协调模型

提前期压缩是企业在激烈竞争环境中赢得与保持竞争优势的一种有效方式。本文制定了一个交易信用(即零售商向供应商提前付款)契约,讨论了可控提前期下非一体化供应链中的库存协作问题,得到了供应商与零售商的最优策略组合。研究表明,当提前期压缩成本系数足够小时,供应商采用所设计的交易信用契约,能够在满足零售商个体理性约束的前提下,赚取可观的成本节约金额,而且比纯粹延期付款协调零售商订货行为时所获得的成本节约更多;并且通过对该成本节约的合理分配,实现了供应商与零售商成本境况的帕累托改进乃至整条供应链的协调。最后的数值分析考察了安全库存系数、提前期需求波动、或者供应商的资金投资收益率对供应链最优策略与成本节约幅度的影响。     

供应商协助库存转运：基于企业实践的创新方法

当企业面临资金约束、资源短缺和消费者需求不确定等不利因素时，库存共享和转运策略的有效实施显得尤为重要。传统研究大多关注零售商协商库存转运机制实施策略，忽略了高效实施传统机制的困难性，即零售商相隔甚远，缺乏信任，协商困难；零售商间私下窜货对供应商和供应链整体造成不利。 提出一类新颖的库存转运机制，即供应商协助转运机制，以突破现存转运方法的不足，从而为实施高效率库存转运提供新的依据。建立由单供应商和多零售商组成的多周期区域分销网络，并考虑零售商在周期初采取前瞻性库存转运；采用动态规划方法刻画对应的优化博弈模型，并通过均衡分析得出供应链成员间均衡博弈策略；通过与集中式供应链运作模式和最优决策相对比，以发掘库存转运过程中存在的不足，总结并提出供应商协助下的新型库存转运机制。从设计过程、实施流程、价格配置等方面对机制的规范实施过程进行详细分析和阐释，并辅以数值分析加以补充论证。 研究结果表明，与传统的零售商协商库存转运机制相比，供应商主导下的协助转运机制优势明显。供应商通过为零售商设置购买和卖出双向交易环节，使零售商在执行补货和清货策略时，同时实现供应链系统内部的库存共享；通过合理的批发价与购买价格和卖出价格配置，如采取随着市场库存整体剩余量增加而降低的转运价格形态，可以迫使零售商在制定最优库存决策以实现其自身利益最大化的同时，有效提升供应链整体运作效率，消除供应链系统内部双重边际效应，最终实现供应链整体收益达到集中式水平以及供应链成员间的完美协调。 提出一类更加易于实施和控制的新型库存转运机制，该机制的运用有助于实现各区域零售商间主动、高效且前瞻性库存转运，同时实现供应链整体收益最大化。建议供应商主动承担协助库存转运职责，同时摒弃传统常数定价机制，转而采取与零售商库存状态相关的批发和转运定价形态。 研究结果对于企业管理者更加合理、规范且高效的开展库存管理，以及实施库存转运和优化资源配置提供了科学的运营理论指导和决策依据。     

库存水平影响需求的变质性产品的供应链协调模型

在考虑市场需求是库存水平线性分段函数、变质性产品和零售商采用(S,s)订货策略的情形下,本文研究了由一个供应商和一个零售商构成的供应链系统运作协调问题。给出了可以实现供应链完美协调的数量折扣策略,理论证明了模型最优解的存在性和唯一性,同时提供了相应的求解方法。数值算例结果表明该折扣模型对于改善供需双方绩效和供应链运作协调是十分有效的。     

基于收益分享契约的VMI模型研究

本文讨论了一个季节性商品销售环境下的供应商管理库存(Vendor Managed Inventory,VMI)模型,建立了零售商与供应商之间的Stackelberg博弈模型,并求出了该博弈的均衡解.在此基础上,文章引入了剩余补贴策略对模型进行了优化,并找到了在协调供应链前提下实现供应链成员期望收益帕累托改进的最优集.用一个算例对结论进行了说明.     

零售货架的线性补贴策略与供应链协调

考虑由一个供应商和一个零售商构成的供应链,供应商提供零售商单一产品,零售阶段的市场需求量随机地依赖于零售商的货架展示量。由于货架空间的稀缺,零售商的成本为非线性的成本函数以符合实际的情况。如果零售商在观察到需求之前决定货架空间,货架补贴可以提高渠道效率;如果零售商在观察需求之后,进行货架决策,补贴降低了供应链效率。由于零售商的努力水平可以验证,供应商可以使用回购加零售货架的线性补贴策略协调供应链,但是需要考虑零售阶段的库存决策与货架分配的决策顺序,而采取完全不同的协调方式。最后通过数值算例说明了所得结论。     

考虑可控提前期和缺货损失的供应链费用分担策略研究

假定在一个由一个供应商与一个零售商组成的供应链中,供应商向零售商提供单一产品且其补货提前期可以通过增加费用进行压缩,零售商的外部需求不确定和部分缺货可以补充,本文建立了供应链分散决策和集中情形下的库存模型,得出了包含最优提前期、订货批量、安全库存因子和生产批量等决策变量的最优解,并提出了买卖双方分担压缩提前期投入费用的策略。算例分析表明,单项费用分担策略虽然能够使提前期压缩到与供应链集中决策时的情形一致,并实现供应链帕累托优化,但无法实现供应链整体最优化。     

决策者过度自信视角下考虑质量控制的供应链库存策略

研究了由单个供应商和零售商组成的供应链中,零售商进行质量控制的条件下,供应链成员对市场需求的过度自信如何影响其库存管理决策和供应商的质量投资。分析了零售商管理库存、供应商管理库存和集中决策三种供应链库存管理模式下供应链成员库存和质量投资决策的博弈均衡,并通过与完全理性下均衡结果的比较探讨了过度自信对供应链成员库存决策、质量投资和利润等的冲击。研究表明,在零售商管理库存模式下,过度自信的决策者对库存量的决策受其心理预期市场需求的正向影响,而在供应商管理库存和集中决策模式下则相反。     

资金约束供应链中的融资优化与营运管理协同决策研究

基于供应商主导的Stackelberg博弈假设,对单一供应商和单一零售商组成的二级供应链中三种购销营运模式(预订购、委托代销和组合模式)的运作及契约双方的博弈顺序进行了分析,并构建了供应链融资和营运协同决策模型。研究表明,资金充足供应链中,供应商的最优状况相当于传统报童模型下的优化问题,且会采用委托代销营运模式。为实现最优决策,资金约束供应商会采用外部融资和供应链内部资金转让的组合融资方案,且会选择预订购和委托代销组合营运策略。资金约束供应链中供应商愿意与零售商分担产品市场风险,激励零售商预订购,增加供应链的整体收益。     

基于供应链间品牌竞争的库存管理策略研究

分析两个供应链间竞争的系统,每条供应链由一个供应商和一个零售商组成,供应商通过各自零售商销售具有品牌差异的产品,不同品牌产品之间存在替代度,零售商面临不确定性需求.在此系统上,存在供应商间的竞争、零售商间的竞争,和供应链内上下游之间的竞争,三种竞争交织.每条供应链有两种管理库存的方式,即零售商管理库存和供应商管理库存.通过对比不同库存管理方式下系统成员收益,发现,把不确定性需求风险从零售商转移给供应商,并非能增加零售商收益,或减少供应商收益;同时,通过分析了不同库存管理方式对供应链系统竞争均衡状态的影响,指出,在一定条件下,供应商管理库存方式能加强供应商端的竞争,使得零售商和供应商共同受益.     

零售商强势的供应链VMI模式演化机理研究

针对目前普遍存在的供应链下游零售商较上游供应商强势的现状,探讨供应商管理库存(VMI)模式的演化机理问题。分别建立了传统库存模式与VMI模式下具有强势零售商的供应链模型,得到不同库存策略下零售商和供应商的支付矩阵。在此基础上,借助双种群演化博弈方法,分别从短期和长期角度对参与双方的演化稳定均衡进行分析。揭示了此供应链结构中,使参与双方获得双赢的VMI能否成功实施的潜在演化机理和关键影响因素。研究结果表明,随着销售量的增加,供应商和零售商在短期和长期的均衡策略分别为(不实施VMI,不实施VMI)和(不实施VMI,不实施VMI)与(实施VMI,实施VMI)共存的情况。进一步分析了利润变化、投资成本与惩罚成本对均衡结果的影响。     

零售商主导型供应链绩效的行为博弈分析

零售商主导型供应链中供应商与零售商的矛盾日益加深,为对该类型供应链作出Pareto改进,研究强势零售商压低供应商批量价格的行为对零售商主导型供应链绩效的影响。首先分别应用经典博弈论和行为博弈论的工具建立完全理性和有限理性背景下供应商和零售商决策的博弈模型,据此将零供双方的交易行为划分为4个不同的演进阶段,最后根据模型的均衡解计算不同演进阶段供应链中各方的绩效,并将结果进行比较。研究结果表明,无论处于交易行为演进的哪个阶段,供应商的绩效都不会优于公平交易下的绩效,零售商和供应链的绩效也不会一直优于公平交易下的绩效。因此,消除零售商对供应商批量价格的打压行为、恢复供应链上下游公平的交易状态是对该类型供应链进行Pareto改进的重要途径之一。     

博弈结构对VMI模式下供应链性能的影响分析

通过建立VMI模式下供应链的多阶段博弈模型,研究分析了VMI中零售商和供应商的不同博弈结构对供应链性能的影响,结果表明,当零售商和供应商之间进行的是双方同时决策的Nash静态博弈时,供应链的性能是最低的,而在一方先决策的动态博弈结构下,供应链的性能会得到明显的改善。最后通过具体的算例分析证实了上述结论。     

Role of Random Capacity Risk and the Retailer in Decentralized Supply Chains with Competing Suppliers

This research considers a supply chain under the following conditions: (i) two heterogeneous suppliers are in competition, (ii) supply capacity is random and pricing is endogenous, (iii) consumer demand, with and without an intermediate retailer, is price dependent. Specifically, we examine how uncertainty in supply capacity affects optimal ordering and pricing decisions, supplier and retailer profits, and the incentives to reduce such uncertainty. When two suppliers sell through a monopolistic retailer, supply uncertainty not only affects the retailer's diversification strategy for replenishment, but also changes the suppliers’ wholesale price competition and the incentive for reducing capacity uncertainty. In this dual‐sourcing model, we show that the benefit of reducing capacity uncertainty depends on the cost heterogeneity between the suppliers. In addition, we show that a supplier does not necessarily benefit from capacity variability reduction. We contrast this incentive misalignment with findings from the single‐supplier case and a supplier‐duopoly case where both suppliers sell directly to market without the monopolistic retailer. In the latter single‐supplier and duopoly cases, we prove that the unreliable supplier always benefits from reducing capacity variability. These results highlight the role of the retailer's diversification strategy in distorting a supplier's incentive for reducing capacity uncertainty under supplier price competition.     

库存成本变化的VMI供应链协调

提出了库存成本变化的经济订货批量(EOQ)模型，基于该模型研究了库存成本变化时供应商管理库存(VMI)系统的最优协议问题。在该系统中，订货商和供应商达成缺货成本共担协议：当缺货发生时，供应商需要向订货商支付缺货补偿。订货商和供应商分散决策，订货商通过设计协议来减少其成本，而供应商通过制定补货决策来缩小自身成本。通过与传统系统和整合系统的比较，得出了库存成本变化时VMI系统的最优补货决策和缺货成本共担协议。采用数值算例验证了分析结果。结果表明，当且仅当供应商预期成本等于整合系统的最小总成本与固定缺货罚金之和时，VMI系统与整合系统具有相同的补货决策和系统绩效，即能够实现供应链协调。     

基于决策者风险规避特性的供应链需求信息共享价值分析

在随机需求条件下,利用条件风险估值(conditional value-at-risk,CVaR)的风险度量准则建立了供应链的需求信息共享决策模型,着重分析了零售商的风险规避程度以及市场需求的不确定性信息对供应链各决策者以及供应链整体信息共享价值的影响。研究结果表明,需求信息共享价值与零售商的风险规避程度、市场不确定性大小以及市场不确定信息所预测的市场需求变化情况有关。数值分析结果表明,零售商越害怕市场的不确定性风险,需求信息共享越有利于提升分散供应链的运作效率;但当市场信息反映出未来的市场需求是消极且零售商接近风险中性时,供应链的需求信息共享价值反而小于零,此时没有进行信息共享的必要。     

A Stochastic Inventory Model With Fast‐Ship Commitments

We present a multiperiod model of a retail supply chain, consisting of a single supplier and a single retailer, in which regular replenishment occurs periodically but players have the option to support fast delivery when customers experience a stockout during a replenishment period. Because expedited shipments increase the supplier's transportation cost, and possibly production/inventory costs, the supplier typically charges a markup over and above the prevailing wholesale price for fast‐shipped items. When fast shipping is not supported, items are backordered if customers are willing to wait until the start of the next replenishment period. We characterize the retailers and the supplier's optimal stocking and production policies and then utilize our analytical framework to study how the two players respond to changes in supply chain parameters. We identify a sufficient condition such that the centralized supply chain is better off with the fast‐ship option. We find a range of markups for fast‐ship orders such that the fast‐ship option is preferred by both the supplier and the retailer in a decentralized chain. However, a markup that is a win–win for both players may not exist even when offering fast‐ship option is better for the centralized chain. Our analysis also shows that depending on how the markup is determined, greater customer participation in fast‐ship orders does not necessarily imply more profits for the two players. For some predetermined markups, the retailer's profit with the fast‐ship option is higher when more customers are willing to wait. However, the retailer may not be able to benefit from the fast‐ship option because the supplier may choose not to support the fast‐ship option when fast‐ship participation increases due to the fact that the fast‐ship participation rate adversely affects the initial order size.     

Managing Slow‐Moving Perishables in the Grocery Industry

We address the value of information and value of centralized control in the context of a two‐echelon, serial supply chain with one retailer and one supplier that provide a single perishable product to consumers. Our analysis is relevant for managing slow‐moving perishable products with fixed lot sizes and expiration dates of a week or less. We evaluate two supply chain structures. In the first structure, referred to as decentralized information sharing, the retailer shares its demand, inventory, and ordering policy with the supplier, yet both facilities make their own profit‐maximizing replenishment decisions. In the second structure, centralized control, incentives are aligned and the replenishment decisions are coordinated. The latter supply chain structure corresponds to the industry practices of company‐owned stores or vendor‐managed inventory. We measure the value of information and value of centralized control as the marginal improvement in expected profits that a supply chain achieves relative to the case when no information is shared and decision making is decentralized. Key assumptions of our model include stochastic demand, lost sales, and fixed order quantities. We establish the importance of information sharing and centralized control in the supply chain and identify conditions under which benefits are realized. As opposed to previous work on the value of information, the major benefit in our setting is driven by the supplier's ability to provide the retailer with fresher product. By isolating the benefit by firm, we show that sharing information is not always Pareto‐improving for both supply chain partners in the decentralized setting.     

供应链内部的折扣博弈

供应链内部的折扣博弈是供应链系统中的一个常见问题,供应商的品牌力度,零售商的网络规模都是决定博弈中议价能力的主要因素,本文将品牌力度从降价促销所带来的品牌销量中分离出来。构建模型衡量各个因素在决定议价能力时所起的作用。并由模型的结果分析了由于信息不对称所导致的“品牌退出”的逆向选择现象。     

Coordinated Logistics: Joint Replenishment with Capacitated Transportation for a Supply Chain

In this study, we consider the integrated inventory replenishment and transportation operations in a supply chain where the orders placed by the downstream retailer are dispatched by the upstream warehouse via an in‐house fleet of limited size. We first consider the single‐item single‐echelon case where the retailer operates with a quantity based replenishment policy, (r,Q), and the warehouse is an ample supplier. We model the transportation operations as a queueing system and derive the operating characteristics of the system in exact terms. We extend this basic model to a two‐echelon supply chain where the warehouse employs a base‐stock policy. The departure process of the warehouse is characterized in distribution, which is then approximated by an Erlang arrival process by matching the first two moments for the analysis of the transportation queueing system. The operating characteristics and the expected cost rate are derived. An extension of this system to multiple retailers is also discussed. Numerical results are presented to illustrate the performance and the sensitivity of the models and the value of coordinating inventory and transportation operations.     

A delay-in-payment contract for Pareto improvement of a supply chain with stochastic demand

We consider a supply chain consisting of a single supplier and a single retailer with stochastic customer demand, which is operated over an infinite horizon. We propose a delay-in-payment contract to coordinate the supply chain. With this contract, the supplier allows the retailer to pay partial order cost at the ordering epoch, and to pay the remaining portion after a permissible number of periods. The system is formulated as a stochastic dynamic programming problem. It is shown that there exists a base-stock policy to be optimal. Compared with the traditional wholesale-price contract, the delay-in-payment contract with appropriate parameters can achieve a Pareto improvement (i.e., the performances of both the supplier and the retailer using the delay-in-payment contract are better than those using the wholesale-price contract). Numerical studies are performed to investigate both the effectiveness of the Pareto improvement, and the impact of the major parameters of the delay-in-payment contract on the system performance.