Managing Demand Uncertainty through Core Acquisition in Remanufacturing

We discuss the optimal raw material acquisition strategy for a third party remanufacturer (3PR). We specifically investigate whether a 3PR should acquire used products or cores in bulk with uncertain quality levels, or in sorted grades with known quality levels; and whether to acquire and remanufacture cores before the demand is realized (planned acquisition), or after the demand is realized (reactive acquisition), or on both occasions (sequential acquisition). When only sorted cores are acquired, we find that, (i) it is optimal to acquire cores in multiple grades to balance acquisition and remanufacturing costs; (ii) if reactive acquisition is possible, it reduces the assortment size (number of grades in which cores are acquired) and the total inventory acquired in the planned acquisition; and (iii) the optimal portfolio of grades to acquire and the optimal acquisition and remanufacturing quantities of these grades can be determined analytically. When bulk cores are acquired in addition to sorted cores, the property of reduction in assortment size of the planned acquisition is preserved. We also show that the 3PR should acquire only a fraction of the demand in planned acquisition, and leave the rest for reactive acquisition. This fraction changes during the lifecycle of a remanufactured product. Using a combination of empirical and realistic data from a smartphone remanufacturer we show that sequential acquisition increases expected profit by up to 8% and 27% over only planned and only reactive acquisitions respectively, and reduces the inventory acquired by up to 21% over only planned acquisition.     

Product Reuse Economics in Closed‐Loop Supply Chain Research

This paper provides a critical review of analytic research on the business economics of product reuse inspired by industrial practice. Insights and critical assumptions are provided for each paper. We further classify the research into four streams: industrial engineering/operations research, design, strategy, and behavioral, and present a framework linking these streams. We find that some modeling assumptions risk being institutionalized, and suggest a renewed exploration of industrial practice. Future research should also include empirical work on consumer behavior, product diffusion, and valuation of returns.     

Closed‐Loop Supply Chains: An Introduction to the Feature Issue (Part 2)

Closed‐loop supply chain management is the design, control and operation of a system to maximize value creation over the entire life‐cycle of a product with dynamic recovery of value from different types and volumes of returns over time. The research in this feature issue furthers our understanding of this rich area and serves as a starting point for another round of research which continues to dig deeper still into relevant industry issues.     

Closed‐Loop Supply Chains: An Introduction to the Feature Issue (Part 1)

Closed‐loop supply chains (CLSC) have product returns at the center of attention. Our view is that CLSC are best managed from a business perspective where organizations seek to maximize value recovery. The research in the feature issue, and our experiences, shows that there are still numerous, unresolved, managerially relevant issues that deserve further investigation. We also observe that there is a pressing need to validate the assumptions in our models using interdisciplinary, industry‐driven research. The time is right for production and operations management to play a central role in the sustainability movement slowly taking hold in practice.     

考虑顾客策略行为和产品质量的闭环供应链决策模型

策略型的顾客对于不同质量的产品以及不同时间的产品会有不同的估值和支付意愿,企业在进行决策时应当考虑顾客的策略性行为。建立了由一个制造商(即原始设备制造商)和一个独立的再制造商以及一组策略型顾客组成的闭环供应链模型,利用动态博弈理论分析了当由独立的再制造商负责回收旧产品并进行再制造时顾客策略行为和再制造品的质量水平对闭环供应链的产品价格、利润、消费者剩余的影响。研究结果表明,当顾客的策略程度增加时,制造商的利润减少,再制造商的利润和消费者剩余增加。当再制造品的质量水平增加时,制造商的利润降低,再制造商的利润先增加后降低,消费者剩余增加。     

供应链中纵向信息获取和横向信息共享策略研究

研究由一个制造商和两个零售商组成的二级供应链中,零售商之间的横向信息共享策略和制造商的信息获取以及最优定价问题。在模型中,制造商同时为两家零售商提供等价商品,零售商向消费者销售商品且进行价格竞争。以Bertrand博弈为研究手段,求解了零售商的均衡销售价格、订货量决策和信息共享策略,制造商的最大利润和最优批发价格,以及供应链利润。分析比较了在制造商不同的信息获取策略下,零售商、制造商和供应链的利润。研究表明,零售商之间完全信息共享始终为占优策略。但制造商获取下游信息时会使得自身利润增加,零售商利润减少,因此零售商不会主动把信息共享给制造商。考虑到下游的边界均衡解,供应链的利润变化还与市场的不确定性和产品的替代性有关。当产品替代性较高或产品替代率较低且市场的不确定性处于中间水平时,制造商获取信息后供应链利润增加,此时制造商可以用部分增加的利润成功购买零售商信息。该模型为上游制造商提供了最优定价和信息获取策略,也为下游零售商提供了求解自身最优销售价格、订货量和信息共享决策的方法。     

Joint Life‐Cycle Dynamics of New and Remanufactured Products

Many products considered for remanufacturing are durables that exhibit a well‐pronounced product life cycle—they diffuse gradually through the market. The remanufactured product, which is a cheaper substitute for the new product, is often put on the market during the life cycle of the new product and affects its sales dynamics. In this paper, we study the integrated dynamic management of a portfolio of new and remanufactured products that progressively penetrate a potential market over the product life cycle. To this end, we extend the Bass diffusion model in a way that maintains the two essential features of remanufacturing settings: (a) substitution between new and remanufactured products, and (b) a constraint on the diffusion of remanufactured products due to the limited supply of used products that can be remanufactured. We identify characteristics of the diffusion paths of new and remanufactured products. Finally, we analyze the impact of levers such as remanufacturability level, capacity profile and reverse channel speed on profitability.     

The Impact of Product Lifecycle on Capacity Planning of Closed‐Loop Supply Chains with Remanufacturing

Product recovery operations in reverse supply chains face rapidly changing demand due to the increasing number of product offerings with reduced lifecycles. Therefore, capacity planning becomes a strategic issue of major importance for the profitability of closed‐loop supply chains. This work studies a closed‐loop supply chain with remanufacturing and presents dynamic capacity planning policies developed through the methodology of System Dynamics. The key issue of the paper is how the lifecycles and return patterns of various products affect the optimal policies regarding expansion and contraction of collection and remanufacturing capacities. The model can be used to identify effective policies, to conduct various “what‐if” analyses, and to answer questions about the long‐term profitability of reverse supply chains with remanufacturing. The results of numerical examples with quite different lifecycle and return patterns show how the optimal collection expansion/contraction and remanufacturing contraction policies depend on the lifecycle type and the average usage time of the product, while the remanufacturing capacity expansion policy is not significantly affected by these factors. The results also show that the collection and remanufacturing capacity policies are insensitive to the total product demand. The insensitivity of the optimal policies to total demand is a particularly appealing feature of the proposed model, given the difficulty in obtaining accurate demand forecasts.     

Distributing a Product Line in a Decentralized Supply Chain

Although there is a rich literature on single product distribution in decentralized supply chains, the incentive problems that arise in distributing a product line have largely not been investigated. In practice, most manufacturers distribute a line of products with different features and qualities and not just a single product. Consider a manufacturer who distributes a product line through competing downstream retailers. In this setting, we investigate how and why the retailers' price and inventory decisions deviate from the centrally optimal decisions. Due to substitution between different product variants, as well as between different retailers, the incentive problems associated with distributing a product line are more complicated than that of distributing a single product. We characterize retailers' incentive distortions under a residual‐claimancy contract, and construct contracts that achieve channel coordination. We show that retail price floors or inventory buybacks, appropriately tailored to each product variant, are among the contracts that can achieve coordination. Using numerical simulations, we demonstrate how the optimal contract terms (such as wholesale prices and buyback prices) for each variant are influenced by the parameters of an underlying consumer choice model.     

The Impact of Modular Assembly on Supply Chain Efficiency

This article studies the impact of modular assembly on supply chain efficiency. In the modular assembly approach, a manufacturer acquires pre‐assembled modules from its suppliers, rather than the individual components, as in the traditional assembly approach. We analyze the competitive behavior of a two‐stage modular assembly system consisting of a manufacturer, and a supplier who pre‐assembles two components into a module. The firms can choose their own inventory policies and we show the existence of Nash equilibrium in the inventory game. Moving from the traditional to the modular approach has a twofold effect on the supply chain. First, we investigate the effect of centralizing the component suppliers. It can be shown that when there is no production time shift, the module supplier always holds more component inventories than suppliers do in the traditional approach, which yields a lower cost for the manufacturer. However, the suppliers, and therefore the supply chain may incur a higher cost in the modular approach. Second, we study the effect of a shift in production time from the manufacturing stage to the supplier stage. From numerical studies, it has been found that such a lead time shift always benefits a centralized supply chain, but not necessarily so for a decentralized system. Combining the two effects, we find that the modular approach generally reduces the cost to the manufacturer and the supply chain, which explains the prevalence of modular assembly from the perspective of inventory management. These results also provide some insight into how firms can improve supply chain efficiency by choosing the right decision structure and lead time configuration.     

两层级分散决策供应链库存转运问题研究

本文考虑一个由制造商及分散决策零售商构成的两层级供应链,研究了库存转运对供应链各方利润的影响。通过构建博弈模型并推导子博弈完美纳什均衡,确定了制造商及零售商的最优决策水平,并确定供应链各方在库存转运下利润提高和降低的条件。理论分析显示,制造商及零售商利润增减均由转运价格决定,转运价格阈值则受临界分位点水平影响。最后给出了零售商进行库存转运的供应链协调契约。     

Strategic Motive for Introducing Internet Channels in a Supply Chain

Rapid advances of information technology in recent years have enabled both the manufacturers and the retailers to operate their own Internet channels. In this study, we investigate the interaction between the capabilities of introducing the Internet channels, the pricing strategies, and the channel structure. We classify consumers into two segments: grocery shoppers attach a higher utility from purchasing through the physical channel, whereas a priori Internet shoppers prefer purchasing online. We find that when the Internet shoppers are either highly profitable or fairly unimportant, the manufacturer prefers to facilitate the channel separation either through his own Internet channel or the retailer's. In the intermediate region, however, the manufacturer encroaches the grocery shoppers and steals the demand from the retailer's physical channel. With horizontal competition between retailers, a priori symmetric retailers may adopt different channel strategies as a stable market equilibrium. The manufacturer may willingly give up his Internet channel and leverage on the retailer competition. When the manufacturer sells through an online e‐tailer, Internet shoppers may be induced to purchase through the physical channel. This reverse encroachment strategy emerges because selling through the e‐tailer leads to a more severe double marginalization problem.     

基于上游成员的机会成本和消费者偏好的供应链产品策略

基于对上游成员的机会成本和消费者在质量偏好上的异质性的考虑,本文研究中心化和由一零售商与一制造商（供应商）组成的分散化供应链在质量和数量上的最优产品策略。通过构建问题的理论模型及分析,分别获得最优解和博弈均衡解。进而利用灵敏度分析和算例讨论了消费者对质量偏好的异质性和上游成员的机会成本对供应链的产品策略、供应链的利润和消费者剩余的影响。研究发现：当边际质量成本较低时,供应链产品策略应主要考虑满足大众需求;而当边际质量成本和消费者对质量偏好的异质性程度都较高时,供应链只需考虑部分高质量敏感的消费者;当消费者对质量的平均偏好水平较低,边际质量成本较高和顾客需求趋于同质时,产品应考虑退出市场;此外,成员的权利均衡有助于完善供应链利润和社会福利,而零售商的强势帮助消费者培育和提高产品质量。最后,占据先动优势的一方在利润分配时基本上占上风。     

供应链、逆向供应链系统的定价策略模型

本文对基于单一制造商和单一零售商构成的供应链、逆向供应链系统进行了研究,应用博弈理论对供应链、逆向供应链系统的定价策略进行了分析,分别得出非合作博弈的均衡解和合作博弈的均衡解,进一步对各种定价策略的效率进行了分析.另外,给出了便于实际操作的协调方法.     

基于产品时间价值的闭环供应链库存策略研究

许多被回收产品的价值会随着时间推移迅速减少,因此如何尽可能地利用库存策略减少此类产品价值的损失就成为了非常值得研究的问题.本文将EOQ模型拓展到闭环供应链中,基于产品的时间价值推导出了允许缺货和不允许缺货两种情况下回收品和成品库存的最优策略,并讨论了产品价值的流失对库存策略的影响.     

逆向供应链中电子废弃产品回收定价和补贴策略研究

随着废弃电子产品的大量涌现和社会环保意识的增强,废弃电子产品的回收处理成为社会关注的热点问题之一。在现有的文献研究中,更多的是从逆向供应链系统化的视角关注价格或税收政策对回收商或处理商的运营效率、积极性的影响,逆向供应链激励的关键问题即如何确定回收价格和补贴方面的研究却较少见。本文基于社会福利最大化的视角,建立斯塔克伯格博弈模型（社会福利模型）来确定逆向供应链分散管理中的回收价格和社会最优补贴费,该模型可以检验分散管理系统（环保局作为领导者、MIS和回收商作为追随者）中回收逆向供应链的回收价格和补贴的激励效应。通过社会福利模型和资金平衡模型的比较,以及比较案例的数值演算,结果发现：达到市场最优销售数量和向顾客提供回收废弃电子产品的最优奖金的状况下,销售商和回收商处于平衡状态;社会福利模型中窒息价格、零奖金对应的基准收集数量、相对于奖金的收集量敏感度等因素对社会福利的影响均优于资金平衡模型。     

考虑产品绿色度的绿色供应链博弈模型及收益共享契约

本文以一个制造商和一个零售商组成的二级绿色供应链为背景,建立了考虑产品绿色度的四种绿色供应链博弈模型:以制造商为主导的Stackelberg博弈模型、以零售商为主导的Stackelberg博弈模型、制造商和零售商的Nash均衡博弈模型以及集中控制模型。对四种博弈模型在产品绿色度、产品价格以及批发价格等方面进行了比较分析,并进一步建立了收益共享契约下的博弈模型。通过数值仿真探讨了收益共享系数对产品绿色度、制造商利润和零售商利润的影响。     

消费者效用视角下双渠道供应链的产品质量研发模式选择研究

考虑到产品质量是影响消费者购买行为的关键驱动因素,运用动态博弈理论和非线性消费者效用函数对双渠道供应链中三种产品质量研发模式分别建模,讨论了各种质量研发模式对供应链成员的利润和消费者效用的影响,并利用二部定价契约协调供应链。三种产品质量研发模式分别为：制造商不进行产品质量研发、制造商独立进行产品质量研发和制造商与零售商合作进行产品质量研发。研究表明：(1)当进行产品质量研发时,批发价、零售价,直销价和产品质量研发水平均提高,并在合作研发下达到最大值,且上述决策变量均随着渠道竞争程度的增加而降低;(2)产品在传统零售渠道和线上销售渠道的销售量和消费者效用随着渠道竞争程度的增加而降低;(3)产品质量研发能够提高制造商的利润和消费者效用,且在合作研发模式下达到最大值;对零售商而言,采用制造商独立研发模式时利润最高,合作研发模式时利润最低;(4)为激励零售商参与研发,制造商利用二部定价契约来协调供应链,协调后产品的研发水平能够达到合作研发时的水平,同时消费者效用增加。数值仿真结果有效地证明了相关结论。     

Competition and Coordination in a Two‐Channel Supply Chain

We study competition and coordination in a supply chain in which a single supplier both operates a direct channel and sells its product through multiple differentiated retailers. We study analytically the supply chain with symmetric retailers and find that the supplier prefers to have as many retailers as possible in the market, even if the retailers' equilibrium retail price is lower than that of the supplier, and even if the number of retailers and their cost or market advantage prevent sales through the direct channel. We find that the two‐channel supply chain may be subject to inefficiencies not present in the single‐channel supply chain. We show that several contracts known to coordinate a single‐channel supply chain do not coordinate the two‐channel supply chain; thus we propose a linear quantity discount contract and demonstrate its ability to perfectly coordinate the two‐channel supply chain with symmetric retailers. We provide some analytical results for the supply chain with asymmetric retailers and propose an efficient solution approach for finding the equilibrium. We find numerically that the supplier still benefits from having more retailers in the market and that linear quantity discount contracts can mitigate supply chain inefficiency, though they no longer achieve perfect coordination.