多分销中心供应链模型及其牛鞭效应的H∞控制

本文在文^[1]具有一个分销中心供应链模型的基础上,建立了具有多个分销中心的供应链结构模型,采用供应链上游库存与订货偏差波动之和与下游顾客需求偏差波动之比描述牛鞭效应。提出顾客末端需求波动最差条件下H_∞控制方法,以抑制牛鞭效应。这一方法本质就是供应链末端需求波动最差情况下,制定供应链管理的最优决策。并且以一个石油分销系统为对象进行了供应链牛鞭效应的H_∞控制仿真实验。     

基于不对称需求信息的供应链最小订购量决策

在由一个供应商和一个零售商组成的两级分散供应链中,供应商通过制定最小订购量取得规模效应,保障自身利益。当零售商和供应商之间存在需求信息不对称时,即零售商掌握需求信息而供应商仅知道需求信息中价格敏感因子的分布,如何进行最小订购量决策成为供应商面临的一个重要问题。针对这一问题,从营销视角构建了基于Stackelberg博弈的利润最大化模型。假设供应商知道需求的价格敏感因子服从正态分布,通过严密的数学推导确定了模型中的最优最小订购量。将提出的最优最小订购量决策方法应用于云存储的销售供应链中,确定了云存储供应商销售的最优最小存储容量,阐释了方法的合理性与有效性。通过实验研究发现,最小订购量的设置提升了供应商的利润。所提方法对于考虑最小订购量的供应链协调研究具有积极的推动作用。     

带学习效应的双渠道供应链库存策略研究

针对具有学习行为的双渠道供应链问题,本文研究了两种分销渠道并存下的最优库存策略。有限计划期内,分销商通过传统销售和在线销售来满足下游顾客的需求。两种分销渠道下的销售单价为时变不减线性函数,当系统中各周期的生产订购固定成本以一定的概率具有学习效应行为时,分别建立了非变质产品生产存贮问题的混合整数约束优化模型以及易变质产品存贮问题的无约束混合整数优化模型,所建立模型的目标为极大化分销商总利润函数。对于这两类模型,通过分析其最优解的性质,利用将生产订购次数松弛为连续变量的技巧证明了最优解存在的唯一性。给出了最优策略的求解方法并比较了两类模型最优利润函数值的大小。最后通过数值算例对上述模型进行了验证,数值结果表明当供应链系统中存在学习效应行为时,该系统能够获得更多的利润。     

两级生产与需求不确定下供应链风险共担模型研究

研究原材料生产、产成品生产以及市场需求不确定下供应链风险共担契约与模型.分析了独立无协调决策与集中决策下,供应链系统的生产与订购决策,证明了独立无协调决策下供应商与制造商之间存在的纳什均衡博弈降低了供应链利润.为了降低供应链主体面临的两级生产与需求不确定性的风险,构建了风险共担协调契约与模型,最后进行了算例分析.研究表明,不考虑两级生产与需求不确定性所进行的决策,使得供应链利润显著降低,说明研究两级生产与需求不确定下供应链运作问题具有重要意义;风险共担协调契约,可以减少两级生产与需求不确定性对供应链效益的影响,提高供应商生产的积极性,使得基于风险共担的供应链利润达到了集中决策供应链的利润水平,从而实现供应链系统的帕累托改进.     

混合需求下考虑专利保护因素的闭环供应链定价与协调

在新产品需求为随机需求,再制造产品需求受销售价格影响的混合需求条件下,以博弈论为主要工具,研究了受专利保护的再制造闭环供应链的定价与协调问题,分析了集中决策和分散决策两种情形下的新产品最优订购量、废旧产品最优回收价格、最优专利许可费用、再制造品最优零售价格以及供应链的最优利润,并通过收益分享一费用分担契约对闭环供应链系统进行了协调,并通过数值算例验证了集中决策和分散决策情形下再制造成本节约对供应链成员的最优决策和利润的影响,以及收益分享.费用分担契约对闭环供应链的协调效果。研究表明再制造受专利保护的情况下,原制造商能通过专利许可费来影响第三方再制造商回收的废旧产品的回收价格和回收量,进而去影响原制造商和第三方再制造商的收益。     

考虑再制造设计水平的多期闭环供应链网络均衡

再制造设计已应用于企业实践,利于产品的再制造过程,但需要额外的投资。本文以多个规划期为决策环境,以包含需求市场层、零售商层和制造商层的闭环供应链网络为研究对象,其中每层包含多个成员,研究了制造商产品可再制造性设计水平决策问题。政府规定最低可再制造设计水平,各制造商对新产品的可再制造设计水平、生产和交易等变量进行决策;正向渠道中零售商同时销售新产品和再制造品,逆向渠道中零售商受制造商委托,在每个规划期末,回收各需求市场产生的废旧品;消费者对新产品和再制造品评价不同,通常对新产品评价较高,而对再制造品评价较低,其对两种产品愿意支付的价格也会不同。利用变分不等式等理论获得制造商和零售商的均衡条件,并获得整个供应链网络均衡模型。采用修正投影收缩算法求解。通过算例对再制造投资影响因子、政府最低可再制造水平、消费者对再制造品的评价系数等参数对均衡结果的影响进行了分析,获得了在多规划期供应链网络环境下,制造商的产品可再制造设计水平和政府有关部门决策时需关注的问题等管理学启示。     

服务具有负溢出效应的异质品双渠道供应链改进策略

针对双渠道供应链中电子直销渠道和传统零售渠道分别销售异质产品的情形,考虑零售商服务对电子直销渠道产品销售的负溢出效应,构建了刻画产品差异和服务溢出效应的消费者效用函数,建立了双渠道供应链的需求模型和利润模型,对比分析了集中式和分散式的最优决策和利润,进而提出了2部定价改进策略。研究表明,实施差异化策略对渠道双方都有利;2部定价契约可以现实供应链的Pareto改进,且契约存在无数多种可以灵活设计。     

基于期望准则和分布自由的回购契约协调模型

将供应链管理引入需求分布自由的市场环境中,以回购契约作为管理的激励机制,研究均为风险中性的供应商—零售商构成的供应链系统的最优订购—定价决策以及回购契约的协调性问题.研究需求分布自由环境下供应链系统的协调性具有重要意义,尤其是对缺乏充分历史销售数据的新产品,短生命周期产品而言.基于期望收益准则和需求分布自由,分别建立供应链系统、零售商和供应商的上界、下界和最小期望收益模型,并在不同的需求依赖价格模式(加型模式和乘型模式)下,分析供应链的最优订购—定价决策以及回购契约的协调性.研究发现,供应链系统的期望收益在由上界向下界乃至退化为最小期望收益时,回购契约的协调能力逐渐增强.即,在上界期望收益模型中,回购契约无法协调供应链系统;在下界期望收益模型中,存在唯一的一组回购契约参数协调供应链系统;在最小期望收益模型中,回购参数是批发价格的反应函数,回购契约可以灵活地协调供应链系统.     

不确定需求下闭环供应链定价模型研究

构建了不确定需求下1个制造商与1个销售商组成的具有产品再造的闭环供应链定价模型.利用博弈理论对2种定价模型进行了分析,得到了一些结论.进一步通过数值仿真定量分析了各模型中新产品制造成本变化对废旧品回收价格、市场销售价格和系统及其成员利润期望值的影响.比较2个定价模型发现集中决策的市场回收价格高于分散决策,销售价格低于分散决策,销售量大于分散决策,系统的利润期望值大于分散决策.     

存在差异性产品的双渠道供应链协调研究

研究存在差异性产品条件下,网络直销渠道与传统零售渠道并存的双渠道供应链系统的协调问题.分别建立了存在单一产品的双渠道供应链需求模型和存在两种差异性产品的双渠道供应链需求模型,并分析了两种情形下供应链最优协调策略,最后进行了算例分析,探讨了网络渠道接受程度、产品差异性程度参数对于供应链及其成员利润的影响.结果表明,双渠道供应链中差异化产品的引入将导致供应链系统利润减少,但更高的产品差异程度能够给Stackelberg博弈占优的制造商带来更高的利润.     

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.     

Lot Sizing for Optimal Collection and Use of Remanufacturable Returns over a Finite Life‐Cycle

Reverse supply chains process used product returns to recover value by re‐processing them via remanufacturing operations. When remanufacturing is feasible, the longer the return flows are delayed during the active (primary) market demand period of the product, the lower the value that can be recovered through these operations. In fact, in order to recover the highest value from remanufactured products, the collection rates, return timings, and reusability rates should be matched with the active market demand and supply. With these motivations, this paper is aimed at developing analytical models for the efficient use of returns in making production, inventory, and remanufacturing decisions during the active market. More specifically, we consider a stylistic setting where a collector collects used product returns and ships them to the manufacturer who, in turn, recovers value by remanufacturing and supplies products during the active market demand. Naturally, the manufacturer's production, inventory and remanufacturing decisions and costs are influenced by the timing and quantity of the collector's shipments of used product returns. Hence, we investigate the impact of the timing of returns on the profitability of the manufacturer‐collector pair by developing system‐wide cost optimization models. Analyzing the properties of the optimal shipment frequency, we observe that the fastest reverse supply chain may not always be the most efficient one.     

回馈与惩罚契约下闭环供应链应对突发事件的协调性研究

考虑一个制造商和一个零售商组成的闭环供应链,在考虑随机性需求下,首先分析了回馈与惩罚契约对闭环供应链的协调作用;然后,探讨了回馈与惩罚契约对突发事件的协调作用,研究表明:基准的回馈与惩罚契约对突发事件将不再发挥协调作用,为此,给出了闭环供应链对突发事件的最优应对策略,并调整了原来的回馈与惩罚契约使其具有抗突发事件性。     

Dynamic Pricing,Production, and Channel Coordination with Stochastic Learning

We consider a decentralized two‐period supply chain in which a manufacturer produces a product with benefits of cost learning, and sells it through a retailer facing a price‐dependent demand. The manufacturer's second‐period production cost declines linearly in the first‐period production, but with a random learning rate. The manufacturer may or may not have the inventory carryover option. We formulate the resulting problems as two‐period Stackelberg games and obtain their feedback equilibrium solutions explicitly. We then examine the impact of mean learning rate and learning rate variability on the pricing strategies of the channel members, on the manufacturer's production decisions, and on the retailer's procurement decisions. We show that as the mean learning rate or the learning rate variability increases, the traditional double marginalization problem becomes more severe, leading to greater efficiency loss in the channel. We obtain revenue sharing contracts that can coordinate the dynamic supply chain. In particular, when the manufacturer may hold inventory, we identify two major drivers for inventory carryover: market growth and learning rate variability. Finally, we demonstrate the robustness of our results by examining a model in which cost learning takes place continuously.     

考虑服务流的产品服务供应链网络均衡模型

产品服务供应链在向客户制造高质量产品的同时，也提供了产品全生命周期的专业服务，服务的嵌入增加了供应链协调的复杂性。考虑产品服务的双重需求，在分析各主体的运作行为的基础上，构建了包括多个制造商和多个销售商的多主体供应链网络；运用变分不等式刻画了制造商层、销售服务集成商层和需求市场的最优运作行为及其达成均衡的条件；最后，通过修正投影算法对数值算例进行了仿真。研究结果表明：产品服务供应链网络中的产品与服务均衡流相互影响，其中，服务水平直接影响到了产品需求；降低产品的售价将有利于服务价格和效益的提升。研究结论进一步印证了在产品服务供应链网络中承载于产品的服务将逐渐成为价值创造的主体。     

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。     

On variance amplification in a three-echelon supply chain with minimum mean square error forecasting

We analyse a three echelon supply chain model. First-order autoregressive end consumer demand is assumed. We obtain exact analytical expressions for bullwhip and net inventory variance at each echelon in the supply chain. All of the three supply chain participants employ the order-up-to policy with the minimum mean square error forecasting scheme. After demonstrating that the character of the stochastic ordering process observed at each level of the supply chain is mathematically tractable, we show that the upper stream participants have complete information of the market demand process. Then we quantify the bullwhip produced by the system, together with the amplification ratios of the variance of the net inventory levels. Our analysis reveals that the level of the supply chain has no impact upon the bullwhip effect, rather bullwhip is determined by the accumulated lead-time from the customer and the local replenishment lead-time. We also find that the conditional variance of the forecast error over the lead-time is identical to the variance of the net inventory levels and that the net inventory variance is dominated by the local replenishment lead-time.     

基于产品安全责任的供应链激励与竞争策略

从产品安全责任入手,基于批发价格合同,运用博弈论的基本思想,对四种情景中供应链的均衡进行分析："非竞争与非激励协调"、"非竞争与激励协调"、"竞争与非激励协调"和"竞争与激励协调"。结果显示：适度的批发价格合同激励协调措施能够提升制造商履行产品安全责任水平、市场需求量、供应链及其各成员的期望收益,但过度激励会降低市场需求量与分销商的期望收益,进而阻滞供应链总期望收益的增加;竞争将降低市场需求量、供应链及其各成员的期望收益;低度激励时竞争将降低制造商履行产品安全责任水平,高度激励时竞争将提升制造商履行产品安全责任水平;供应链采用批发价格合同激励协调机制能够增强其对外部的竞争能力,但过度竞争将降低制造商履行产品安全责任水平,进而对供应链及其各成员的利益造成损害。研究成果对供应链的产品安全责任管理实践有重要的指导意义。     

Interorganizational Collaborative Forecasting and Replenishment Systems and Supply Chain Implications

Collaborative Forecasting and Replenishment (CFAR) is a new interorganizational system that enables retailers and manufacturers to forecast demand and schedule production jointly. The capabilities of CFAR exceed those of the traditional EDI because CFAR allows exchange of complex decision support models and manufacturer/retailer strategies. The proponents of CFAR claim that the fastest way for retailers and manufacturers to slash inventory costs and product shortages is by coordinating their decisions. The impact of CFAR on the supply chain using a model consisting of a manufacturer selling its product through two independent identical retailers is analyzed. The model assumes that the manufacturer doesn't face capacity constraints, the demand is stationary, and retailer prices are constant over time; the shortages are backordered at the manufacturer and retailers to isolate the effects of information sharing in CFAR. The most significant findings relate to the increase in the cost incurred by the nonparticipant in CFAR, the increase in the manufacturer's cost of serving the nonparticipant if the participant can obtain delivery guarantees in return for demand information sharing, and the incentives of the players to move towards universal retailer participation in CFAR. The findings are explained using the risk structure faced by the players in the supply chain. The managerial implications of the impact of CFAR on the supply chain structure are also discussed.     

消费者锚定效应下的动态定价与库存控制研究

在零售商-消费者两级供应链中, 零售商垄断销售市场, 研究基于消费者锚定效应的动态定价与库存问题。将消费者的锚定效应纳入决策模型中, 探讨消费者锚定的参考价格与产品的市场需求、价格的动态变化关系;利用动态规划理论建立了消费者锚定效应的动态定价与库存模型;在此基础上考虑利润折现和库存积压问题, 并分别构建了相应模型。数值分析表明, 消费者会根据市场价格的变化决定最佳的购买时机, 零售商的期望收益随着销售时间的延长而增加。