Supply Chain Management of Fresh Products with Producer Transportation*

This article considers a class of fresh‐product supply chains in which products need to be transported by the upstream producer from a production base to a distant retail market. Due to high perishablility a portion of the products being shipped may decay during transportation, and therefore, become unsaleable. We consider a supply chain consisting of a single producer and a single distributor, and investigate two commonly adopted business models: (i) In the “pull” model, the distributor places an order, then the producer determines the shipping quantity, taking into account potential product decay during transportation, and transports the products to the destination market of the distributor; (ii) In the “push” model, the producer ships a batch of products to a distant wholesale market, and then the distributor purchases and resells to end customers. By considering a price‐sensitive end‐customer demand, we investigate the optimal decisions for supply chain members, including order quantity, shipping quantity, and retail price. Our research shows that both the producer and distributor (and thus the supply chain) will perform better if the pull model is adopted. To improve the supply chain performance, we propose a fixed inventory‐plus factor (FIPF) strategy, in which the producer announces a pre‐determined inventory‐plus factor and the distributor compensates the producer for any surplus inventory that would otherwise be wasted. We show that this strategy is a Pareto improvement over the pull and push models for both parties. Finally, numerical experiments are conducted, which reveal some interesting managerial insights on the comparison between different business models.     

供应商产出随机与供应中断下的双源采购决策

研究在需求与供应不确定条件下,一个制造商向两个存在产出随机和供应中断可能性的供应商采购零部件时的最优决策问题。论文分别针对两种情况：（1）只考虑供应商产出随机,（2）同时考虑供应商产出随机与供应中断可能性,建立了两种情况下制造商与两个供应商之间的博弈模型,证明了在两种情况下,制造商均存在最优订货量、供应商存在最优生产量使自身利润最优。研究发现,供应商产出稳定性的改善（即产出随机性降低）不仅可以使自身获得更大的利润,也使制造商获得更大的利润。供应商最优生产量随着自身产出随机性降低先增后减。同时,供应商供应中断可能性的降低会为自身带来更大的收益,也为制造商带来更大的收益。     

The single-period inventory problem: Extension to random yield from the perspective of the supply chain

A special form of the single-period inventory problem (newsvendor problem) with a known demand and stochastic supply (yield) is studied. A general analytic solution for two types of yield risks, additive and multiplicative, is described. Numerical examples demonstrate the solutions for special cases of uniform distribution yield risks. An analysis of a two-tier supply chain of customer and producer reveals that the customer may find it optimal to order more than is needed, since a larger order increases the producer's optimal production quantity.     

供需同时不确定关系型供应链契约设计与决策

在同时面临随机产出（random yield）和随机需求的供应链中,引入基于现实应用设计的具有声誉效用机制和信任机制的承诺契约,同时考虑紧急采购,建立多重不确定关系型供应链决策模型。分析该类型集中式供应链（CSC：centralized supply chain）和以Stackelberg博弈为基础的分散式供应链（DSC：decentralized supply chain）的最优供应、采购策略存在性及其条件,应用逆向推导法探讨供需双方的博弈过程;通过绝对和相对指标分析供应链及其成员的绩效;结合理论推导和数值试验对承诺契约参数、供应链及其成员最优策略和期望收益做关于供需不确定性、紧急采购价格的敏感性分析。     

Gray Markets,A Product of Demand Uncertainty and Excess Inventory

Diverting large quantities of goods from authorized distribution channels to unauthorized or “gray market” channels, albeit legal, significantly affects both firms and consumers due to effects on price, revenue, service and warranty availability, and product availability. In this paper we consider mechanisms by which the uncertainty surrounding inventory ordering decisions drives gray markets. We start with a minimal stochastic supply chain model composed of a producer and a retailer; then we restructure the model to add a distributor whereby the distributor and authorized retailer have the option of diverting inventory to a gray market. Our analysis sheds light on three issues: impacts of diversion on the various supply chain participants, strategies producers could use to combat or exploit gray markets, and important considerations for authorized retailers trying to set optimal order quantities in the presence of a gray market. Our analysis yields new insights into the behavior and impact of gray markets, which can inform management strategies and policies for confronting them.     

突发性产出下的供应链协调应对策略

针对突发事件影响制造商产出的情形，研究了收益共享契约协调应对突发产出事件的有效性问题。首先论证了无突发产出事件时收益共享契约协调供应链的有效性，进而分析了突发产出事件对供应链最优生产计划、定价决策、绩效和协调性的影响。然后，建立了突发产出事件下的收益共享契约协调应对模型，并对原收益共享契约和修正后的收益共享契约进行了对比分析。研究表明：当突发产出事件导致产出扰动范围较小时，供应链的最优生产计划、批发价格和零售价格几乎保持不变，仅当产出扰动范围较大时，三者才需要同时调整，此时原供应链的协调性也将被打破，而修正后的收益共享契约具有良好的抗突发性。最后，通过算例进行了验证。     

考虑技术研发和物流配送的医药供应链组合契约协调模型研究

两票制政策的实施使医药供应链管理模式发生了重大变化,也使供应链成员的决策更加复杂。为了确保药品高效、及时、持续的供应,本文研究由一个医药生产企业、一个医药流通企业和一个药店/医院组成的三级供应链的医药定价与协调问题。考虑市场需求受医药生产企业的技术研发和医药流通企业的物流配送影响的情况下,以合作决策的市场价格和最优利润为基准,采用收益共享+数量折扣组合契约作为激励机制,建立了分散决策下供应链组合契约协调模型,探究技术研发和物流配送能力对医药供应链及成员的影响。通过算例分析发现：实施收益共享+数量折扣组合契约策略可以有效的优化和协调医药供应链,能够激励医药生产企业努力提升技术研发水平,激励医药流通企业努力提升物流水平,实现整个医药供应链的帕累托最优。     

新鲜度信息不对称下生鲜农产品供应链协调

生鲜农产品供应链上下游存在新鲜度信息的不对称性,加剧了耗损。为此,迫切需要研究生产商隐瞒新鲜度信息的生鲜农产品供应链协调。基于Stackelberg博弈,使用单周期报童模型分别构建生产商和零售商的利润函数,分析供应链性质;并提出具体的回购契约形式进行供应链协调。研究认为：一般的批发价格契约下,即使生产商隐瞒农产品新鲜度信息,也不一定损害供应链总收益;回购契约可以保证新鲜度信息共享并协调供应链。最后,通过数值算例验证分析结论的有效性。     

Fresh-product supply chain management with logistics outsourcing

We consider a supply chain in which a producer supplies a fresh product, through a third-party logistics (3PL) provider, to a distant market where a distributor purchases and sells it to end customers. The product is perishable, both the quantity and quality of which may deteriorate during the process of transportation. The market demand is random, sensitive to the selling price as well as the freshness of the product. We derive the optimal decisions for the three supply chain members, including the 3PL provider's transportation fee, the producer's shipping quantity and wholesale price, and the distributor's purchasing quantity and retail price. We find that the presence of the 3PL provider in the supply chain has a significant impact on its performance. We propose an incentive scheme to coordinate the supply chain. The scheme consists of two contracts, including a wholesale-market clearance (WMC) contract between the producer and the distributor, and a wholesale-price-discount sharing (WDS) contract between the producer and the 3PL provider. We show that the proposed contracts can eliminate the two sources of “double marginalization” that exist in the three-tier supply chain, and induce the three parties to act in a coordinated way.     

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.     

基于期权合约的供应链协同决策研究

本文在市场需求和价格不稳定的双重背景下,研究以风险规避为目的的供应商如何在供应链管理中运用期权合约实现利润最大化的途径问题。供应商通过在二级供应链中引入实物期权,在购买方需求不确定时可以将其引致的风险转移向供应方,而供应方的风险通过来自期权合约的额外收益在最大程度上被平衡。本文在分析考虑期权因素的决策模型中,研究市场需求以随机分布状态变化时,构建具有期权合约的最优利润最大化模型问题。数值算例验证了期权合约策略模型的可行性。本研究在一定程度上完善了供应链中期权合约的风险规避模型,为供应链企业风险管理的决策依据提供了有用的实践参考价值。     

具有两阶段生产模式和需求信息更新的供应链契约研究

针对二级供应链,在基于Stackelberg博弈的批发价契约中,分析了折扣价格与零售商最优提前订购量的关系及对契约双方期望收益的影响;设计了价格折扣与回购联合的协调契约,分析了供应链系统的最优提前生产量、供应链协调条件及协调契约下制造商和零售商的期望收益变化,并在协调契约不满足制造商的个体理性约束时,提出采用不对称Nash谈判模型设计两阶段生产与订购的回购契约,在保证供应链系统整体绩效最优的条件下,使制造商和零售商利润都能得到满意增长。研究表明,三级供应链实行两阶段订购的必要条件是分销商与零售商的最优提前订购量相等,与二级供应链相比,价格折扣契约下三级供应链效率更低,但价格折扣与回购联合的契约同样能协调三级供应链,该协调契约满足零售商与分销商激励相容约束。     

存在议价能力和副产品协同生产的制造商最优产量决策

考虑由环保型制造商和处理厂构成的两级供应链结构，其中上游制造商进行主产品的生产，而下游处理厂通过对废料加工进行副产品的生产。基于供应链成员之间存在不同议价能力的情形，构建了上游制造商将产生的废料给下游进行处理的协同生产模式，给出了主产品的均衡产量决策和废料的最优交易价格以及制造商关于废料的最优处理策略。研究结果表明，制造商的废料处理策略取决于消费者对副产品产量的敏感程度。当消费者对副产品产量较敏感（不敏感）时，制造商会选择自己处理废料（给处理厂进行加工）。此外，随着制造商议价能力的上升，制造商的均衡利润上升，而处理厂的均衡利润下降。最后发现本文的基本结论在随机产出环境下依然稳健。     

产能不确定供应商的风险厌恶行为对供应链的影响

针对具有产能不确定性的风险厌恶供应商和风险中性零售商组成的供应链系统,本文采用经典的风险指标Value-at-risk(VaR)衡量供应商的风险厌恶程度,并将其作为供应商的优化约束条件之一。在斯坦伯格顺序博弈的模型框架下,零售商做定价和订货量决策,供应商做批发价决策。本文求得供应商批发价在VaR约束下的理论上下界,研究了风险厌恶程度对最优批发价的影响。与风险中性环境下的结果相比,在设立合理目标利润的前提下,高风险厌恶程度可能使得供应商提高批发价,低风险厌恶程度则对供应商批发价无影响。当目标利润设立很高时,供应商为了逐利将会降低批发价诱导零售商提高订货量。     

非对称信息供应链质量信号传递博弈分析

基于博弈论和委托代理理论,研究了非对称信息条件下供应链节点企业间如何进行质量信号传递的问题。供应商对生产过程投资水平进行决策并采取质量预防策略,为获得最优质量契约可将其生产过程水平类型以信号传递给生产商,其对接收到的中间部件或原材料进行质量评价决策和加工处理决策。运用最优化原理,构建了生产商产品质量决策控制模型,并对生产商支付的"信息租金"进行了量化的描述并进行了仿真检验,结果证明:供应商有激励性动机将其生产过程水平类型以信号传递给生产商,并提高中间部件或原材料质量水平;当生产商观测到供应商所提供的产品质量信号后,将降低其产品质量检验水平、提高加工处理水平,增加向供应商的前向支付,作为对供应商提高产品质量水平的质量奖励,同时整个供应链的联合期望收益将显著增加,并使生产商为获取供应商产品质量水平向其支付的"信息租金"减少。最后论证了供应商进行产品质量信号传递过程中"棘轮效应"的成因,并给出了以上各结论相应的定量分析与证明。     

Optimization and Coordination of Fresh Product Supply Chains with Freshness‐Keeping Effort

We consider a supply chain in which a distributor procures from a producer a quantity of a fresh product, which has to undergo a long‐distance transportation to reach the target market. During the transportation process, the distributor has to make an appropriate effort to preserve the freshness of the product, and his success in this respect impacts on both the quality and quantity of the product delivered to the market. The distributor has to determine his order quantity, level of freshness‐keeping effort, and selling price, by taking into account the wholesale price of the producer, the cost of the freshness‐keeping effort, the likely spoilage of the product during transportation, and the possible demand for the product in the market. The producer, on the other hand, has to determine the wholesale price based on its effect on the order quantity of the distributor. We develop a model to study this problem, and characterize each party's optimal decisions in both decentralized and centralized systems. We further develop an incentive scheme to facilitate coordination between the two parties. Computational results are reported to show the effects of freshness‐keeping efforts.     

不确定性环境下不同补货策略的供应链契约协调研究

针对产出和需求不确定性导致的残值或补货问题,考虑单个制造商和零售商所组成的双边随机供应链,双方采取事前订单形式,构建两种不同现货市场补货策略模型,研究随机环境下最优原材料投入量-成品订货量决策行为及供应链协调。研究表明：零售商自行补货时,收益共享合同不能分担上游产出不确定性风险,制造商为避免产出过剩会减小投入量导致合同失效,但融合了缺货惩罚-余货补偿双向机制的收益共享契约能够进行有效协调。当由制造商补货时,现货市场降低了产出不确定性风险且提高了系统产出投入比,并能重新使收益共享契约生效。此外,有效契约协调后的各方收益均为系统最优收益的仿射函数,并由协商后的收益共享比例控制着分配系数。理论分析和数值仿真说明了合同协调的有效性。算例分析还发现,设计的收益共享风险共担契约相比单一的收益共享契约能够更好地降低不确定性对收益的影响。     

基于合同理论的逆向供应链定价策略研究

利用合同理论的方法,借鉴类似回购合同的假设,研究"制造商-零售商"二级供应链中3种不同质量水平的产品回收最优定价问题,以最大化零售商、制造商和供应链的利润。该闭环供应链中只有一个制造商和零售商,零售商负责产品的回收。从分析可知,通过调整参数值,在回收率确定或随机的情况下供应链都可以达到协调,也都可以找到最优订货量和回收价格。研究发现,零售商的最优价格与最优订货量紧密相关,制造商的回收价格并不影响供应链的总体利润。     

保证保险和产出不确定下订单农业供应链融资中的政府补贴机制

在贷款保证保险及农产品产出不确定性下，考虑农户受资金约束及政府补贴贷款利息，针对订单农业供应链融资中的农户存在破产风险情形，研究了政府、银行、公司及农户之间的四阶段动态博弈问题；并在分析政府补贴对供应链最优决策及各方利益的影响后，得到了社会福利最大化下的政府补贴机制。研究发现，（1）若丰收年的投入产出率超过灾害年的投入产出率2倍，政府应提供补贴机制。（2）政府补贴机制应为：①当价格敏感系数小于一定值时，政府不应提供补贴。②当价格敏感系数适中时，政府应提供部分补贴。③当价格敏感系数大于一定值时，政府应提供全额补贴。④特别地，当灾害年与丰收年的投入产出率比值提升到一定值时，政府始终应提供补贴，甚至当投入产出率比值提升到更大值时，政府应提供全额补贴。最后对"政银保"合作贷款新模式提出改进建议。     

电子市场环境下供应链运作的鲁棒优化模型

本文研究了电子市场环境下的供应链运作问题,提出了不确定环境下的鲁棒优化模型.这一研究的实质是在外界需求最差条件下,如何得到电子市场中供应链最优供应量的策略.文中采用区间方法,设计供应链运作的鲁棒最优策略.进一步,在电子市场不确定环境下,进行了鲁棒策略仿真工作,结果表明鲁棒策略能为决策者提供最坏情况下供应商提供产品数量的鲁棒解决方案.