Optimal acquisition and production policy in a hybrid manufacturing/remanufacturing system with core acquisition at different quality levels

We study the acquisition and production planning problem for a hybrid manufacturing/remanufacturing system with core acquisition at two (high and low) quality conditions. We model the problem as a stochastic dynamic programming, derive the optimal dynamic acquisition pricing and production policy, and analyze the influences of system parameters on the acquisition prices and production quantities. The production cost differences among remanufacturing high- and low-quality cores and manufacturing new products are found to be critical for the optimal production and acquisition pricing policy: the acquisition price of high-quality cores is increasing in manufacturing and remanufacturing cost differences, while the acquisition price of low-quality cores is decreasing in the remanufacturing cost difference between high- and low-quality cores and increasing in manufacturing and remanufacturing cost differences; the optimal remanufacturing/manufacturing policy follows a base-on-stock pattern, which is characterized by some crucial parameters dependent on these cost differences.     

Product-design and pricing strategies with remanufacturing

In this paper, we consider a supply chain that consists of an original equipment manufacturer (OEM) producing new products and a remanufacturer recovering the used items. The OEM often faces a strategic dilemma when determining the degree of disassemblability of its product design, as high disassemblability decreases the OEM’s production costs as well as the remanufacturer’s recovery costs. However, high disassemblability may be harmful to the OEM in a market in which the remanufacturer is encouraged to intensify price competition with the OEM because design for high disassemblability leads to larger cost savings in remanufacturing. We first formulate a two-period model to investigate the OEM’s product-design strategy and the remanufacturer’s pricing strategy in an extensive-form game, in which the equilibrium decisions of the resulting scenarios are derived. Next, we show the thresholds that determine whether remanufacturing is constrained by collection, the thresholds for the remanufacturer’s choice of a profitable pricing strategy, and the thresholds for determining the OEM’s product-design strategy. Finally, we expand the model for a multiple-period problem to show that the main insights obtained from the two-period model can be applied.     

Dynamic pricing of remanufacturable products under demand substitution: a product life cycle model

We consider a manufacturer who sells both the new and remanufactured versions of a product over its life cycle. The manufacturer’s profit depends crucially on her ability to synchronize product returns with the sales of the remanufactured product. This gives rise to a challenging dynamic optimization problem where the size of both the market and the user pool are dynamic and their current values depend on the entire history. We provide an analytical characterization of the manufacturer’s optimal pricing, production, and inventory policies which lead to a practical threshold policy with a small optimality gap. In addition, our analysis offers a number of interesting insights. First, the timing of remanufacturing activity and its co-occurrence with new product manufacturing critically depends on remanufacturing cost benefits, attractiveness of the remanufactured product and product return rate. Second, there is a small upward jump in the price of the new product when remanufacturing is introduced. Third, the manufacturer keeps the new product longer on the market as the cost of remanufacturing decreases. Fourth, partially satisfying demand for the remanufactured item is never optimal, i.e., it is satisfied either fully or not at all. Finally, user pool and inventory of returned products are substitutes in ensuring the supply for future remanufacturing.     

授权再制造视角下再制造设计对制造再制造影响研究

为分析授权再制造下, 再制造设计对制造/再制造影响, 构建了再制造设计不同承担模式下原始制造商与再制造商博弈模型, 对比分析再制造设计费用不同承担模式下, 再制造设计对最优纳什均衡解影响。研究主要得到:授权再制造不仅可以改变原始制造商市场竞争不利地位, 还可以增加其收益; 在授权再制造下, 只有再制造设计带给两种单位产品收益之比较大时, 两者才愿意承担再制造设计费用; 虽然再制造设计可以减少两种产品单位零售价格, 但是再制造设计不一定总是增加消费者剩余。     

回收量不确定下考虑技术授权的闭环供应链产品定价研究

越来越多的企业开始采取再制造的运作模式以缓解资源浪费和环境危机。原始设备制造商(OEM)为专注于新产品制造,可通过技术授权的方式委托第三方再制造商(TPR)进行再制造活动。本文研究了回收量不确定且OEM技术授权TPR进行再制造情形下闭环供应链的产品定价问题。研究发现:(1)当废旧品回收量在较小范围波动时,OEM和TPR若想获得不低于确定情形下的利润需考虑企业风险规避程度的影响;(2)当废旧品回收量在较大范围波动时,OEM和零售商在分别制定产品批发价和零售价时需按废旧品回收量波动方向相反的方向进行;(3)在废旧品回收量波动情形下,OEM应优先选择与风险中性的TPR合作,再适当降低技术授权费用使得TPR有利可图,这样既有利于促进废旧品的回收,也益于双方合作关系的持续发展。     

On the optimal control of manufacturing and remanufacturing activities with a single shared server

We consider a single-product make-to-stock manufacturing–remanufacturing system. Returned products require remanufacturing before they can be sold. The manufacturing and remanufacturing operations are executed by the same single server, where switching from one activity to another does not involve time or cost and can be done at an arbitrary moment in time. Customer demand can be fulfilled by either newly manufactured or remanufactured products. The times for manufacturing and remanufacturing a product are exponentially distributed. Demand and used products arrive via mutually independent Poisson processes. Disposal of products is not allowed and all used products that are returned have to be accepted. Using Markov decision processes, we investigate the optimal manufacture–remanufacture policy that minimizes holding, backorder, manufacturing and remanufacturing costs per unit of time over an infinite horizon. For a subset of system parameter values we are able to completely characterize the optimal continuous-review dynamic preemptive policy. We provide an efficient algorithm based on quasi-birth–death processes to compute the optimal policy parameter values. For other sets of system parameter values, we present some structural properties and insights related to the optimal policy and the performance of some simple threshold policies.     

Production planning for hybrid remanufacturing and manufacturing system with component recovery

In this paper, we address component recovery under the condition of limited resources from the OEM's (Original Equipment Manufacturer's) standpoint. We develop a linear programming model for a hybrid remanufacturing and manufacturing system for production planning problems with deterministic returns. In this paper, a data set from an OEM that both remanufactures and manufactures the products is used to demonstrate the performance of the proposed model. Subsequently, an analysis of the impact of the remanufactured product’s price and the quantity of returns on revenue and total cost will be discussed. We have found that uncertain factors of manufacturing influence the profit and uncertain factors of remanufacturing influence the production planning, such as the rate of the yield on component remanufacturing and the quantity of returns.     

两阶段再制造企业的产品定价研究

二手产品的回收再处理是众多制造商和再制造商不得不面对的问题.企业根据实际情况,考虑到顾客对再制造产品的认知差异,一般都是先翻新产品然后再升级再制造产品,因此,顾客对再制造产品的接受程度影响着再制造企业的定价决策,针对该问题构建了一个两阶段模型,其中第一阶段再制造企业将回收的产品进行简单翻新并投放市场;第二阶段,则会将产品拆卸加工再升级.以两阶段的价格作为决策变量分析再制造企业的最优生产策略.通过仿真得出结论,为再制造企业的生产决策提供一些依据.     

基于产品生命周期的闭环供应链定价和协调策略研究

研究产品生命周期条件下一个制造商、一个零售商组成的闭环供应链的定价和协调策略:制造商第一周期只生产新品,从第二周期开始生产再制造品,并负责回收。建立了两周期、多周期和无限周期下的分散决策模型和多周期下的集中决策模型,得到最优定价和生产策略。结果表明:两周期中,制造商和零售商应根据不同的成本节约额制定不同的批发价、零售价和生产量。多周期中,当成本节约额比较小时,除第一和最后一个周期外,制造商和零售商应采取相同的定价和生产策略;当成本节约额比较大时,除第一和最后两个周期外,制造商和零售商应采取相同的定价和生产策略。无限周期中,除第一周期以外,制造商和零售商都应该采取相同的定价和生产策略。在有限周期情况下,制造商和零售商应通过在前期制定比较低的批发价和零售价,以提高生产量和销售量,使得后期的回收量增大,达到降低成本的目的。通过引入收益共享契约制定合适的批发价和销售收入及再制造收益共享比率可以协调整个闭环供应链。算例验证了上述结论。     

Pricing used products for remanufacturing

Remanufacturing is one of recovery options for used products. As remanufacturing requires a continuous supply of used products, the economic incentive is required to attract customers to return their used products (called cores) and the problem of pricing a core becomes an important issue. Such a pricing problem is analogous to pricing an option, which can be used to sell the remanufactured cores (called core products). As sales price of core products follows a geometric Brownian motion, we propose a model here to evaluate the acquisition price of cores. This model links core acquisition price with the sale price of core product but assumes other costs such as logistics and remanufacturing to be deterministic. We have presented a numerical example to show its applicability. Since the model proposed here is generic, it is believed that the proposed model can be used in setting the core prices in many situations.     

Supply planning models for a remanufacturer under just-in-time manufacturing environment with reverse logistics

We study a supply planning problem in a manufacturing system with two stages. The first stage is a remanufacturer that supplies two closely-related components to the second (manufacturing) stage, which uses each component as the basis for its respective product. The used products are recovered from the market by a third-party logistic provider through an established reverse logistics network. The remanufacturer may satisfy the manufacturer’s demand either by purchasing new components or by remanufacturing components recovered from the returned used products. The remanufacturer’s costs arise from product recovery, remanufacturing components, purchasing original components, holding inventories of recovered products and remanufactured components, production setups (at the first stage and at each component changeover), disposal of recovered products that are not remanufactured, and coordinating the supply modes. The objective is to develop optimal production plans for different production strategies. These strategies are differentiated by whether inventories of recovered products or remanufactured components are carried, and by whether the order in which retailers are served during the planning horizon may be resequenced. We devise production policies that minimize the total cost at the remanufacturer by specifying the quantity of components to be remanufactured, the quantity of new components to be purchased from suppliers, and the quantity of recovered used products that must be disposed. The effects of production capacity are also explored. A comprehensive computational study provides insights into this closed-loop supply chain for those strategies that are shown to be NP-hard.     

基于回收风险的闭环供应链差异定价决策研究

随着资源的匮乏和环境污染的加剧,越来越多的企业和消费者开始关注废旧产品的回收再制造。针对制造商唯一寡头垄断市场竞争结构,引入回收风险,分别对制造商(OEM)自行回收废旧产品的闭环供应链、第三方回收商回收废旧产品的闭环供应链建立数学模型,分析给出各企业的最优差异定价规则,并从经济学意义上得到相关管理启示;数值实验的结果则进一步验证回购价格、回收风险、价格竞争强度对最优解的影响。研究结果表明:(1)闭环供应链结构会影响再制品价格及废旧产品的回收价格,但对OEM新品定价无影响。(2)回收风险的变化对价格决策的影响取决于闭环供应链的结构特征。当回收风险较低时,在激发消费者对再制品需求、促使消费者返回废旧产品、提升闭环供应链整体效率等方面,OEM自行回收模式优于第三方回收商回收模式;而当回收风险较高时,则第三方回收商回收模式优于OEM自行回收模式。(3)回收风险的降低使得闭环供应链总利润呈现出增长的趋势,进而进一步体现到再制造的经济价值。(4)OEM自行回收废旧产品需考虑到新品与再制品间的价格竞争强度,当价格竞争强度较弱时,OEM自行回收废旧产品可为OEM带来更多的利润;新品与再制品间的价格竞争也有利于再制品需求的提升。     

Transnational remanufacturing decisions under carbon taxes and tariffs

Considering the influence of carbon taxes and tariffs on transnational closed-loop supply chains, this paper establishes three remanufacturing modes of an original equipment manufacturer (OEM) in an exporting country. In one remanufacturing mode, the OEM conducts remanufacturing itself, and in the other two modes, the OEM authorizes a retailer in the importing country to engage in remanufacturing. Next, we analyse the optimal pricing and carbon emissions reduction decisions of the OEM and retailer in the different modes and further study how different levels of carbon tax and tariff combinations impact OEM remanufacturing decisions, the social welfare of importing countries and the environment. The results show the following. (1) When the carbon tariff is high, the optimal sales of remanufactured products increase. However, this does not contribute to the continuation of the product system; thus, it is short sighted for the government to hastily set high carbon tariffs to discourage the import of new products to protect domestic enterprises. (2) Carbon tariffs cannot effectively encourage the OEM to invest in emission reduction because carbon tariffs are passed on to consumers in importing countries through price adjustment. However, carbon tax may be an indirect factor affecting the OEM's willingness to invest in emission reduction. (3) The OEM favours allowing the retailer to remanufacture when the carbon emissions of the remanufactured products are similar to those of new products. Co-investment in emission reduction has the potential to align the profit maximization of the OEM with the social welfare maximization of the importing country. (4) It is not profitable for the importing government to set high carbon tariffs to protect its own enterprises.     

Heuristics with guaranteed performance bounds for a manufacturing system with product recovery

We consider a manufacturing system with product recovery. The system manufactures a new product as well as remanufactures the product from old, returned items. The items remanufactured with the returned products are as good as new and satisfy the same demand as the new item. The demand rate for the new item and the return rate for the old item are deterministic and constant. The relevant costs are the holding costs for the new item and the returned item, and the fixed setup costs for both manufacturing and remanufacturing. The objective is to determine the lot sizes and production schedule for manufacturing and remanufacturing so as to minimize the long-run average cost per unit time. We first develop a lower bound among all classes of policies for the problem. We then show that the optimal integer ratio policy for the problem obtains a solution whose cost is at most 1.5% more than the lower bound.     

再制造市场OEM与UOEM的博弈与学习研究

在再制造利益的驱动下,一些非原始设备制造商(UOEM)欲进入再制造市场。为探究UOEM参与再制造的进入博弈,应用演化博弈理论构建了原始设备制造商(OEM)和UOEM策略选择的复制动态。研究表明:博弈双方的回收价格、UOEM排除障碍的成本会影响UOEM的策略选择;OEM选择默许而潜在的UOEM进入再制造品市场是二维动态系统唯一的演化稳定策略。进一步考虑了参与人的学习行为,将噪声项引入复制动态方程中,得到了一个非子博弈完美均衡,即当带着噪声项的OEM采取竞争策略时,进入者的最优策略是置身于市场之外。     

基于碳关税和配额的再制造决策研究

在跨国闭环供应链中考虑碳关税、碳配额和碳税三种政策的影响,分别建立了出口国制造商(OEM)再制造模型和OEM授权进口国零售商进行再制造模型,得到不同模型中OEM和零售商的最优价格、最优销售量、最优利润,进一步分析了产品碳排放总量是否超过配额的不同情形下新产品碳排放量对新产品和再制造品价格、销售量的影响以及其中碳关税和碳税发挥的作用.结果表明,在配额限制下,存在碳关税、碳税以及两种政策共同约束的取值区间,当税率水平在不同区间时,新产品碳排放量对两种产品的价格、销售量有不同的影响.     

Optimal core acquisition and remanufacturing policies under uncertain core quality fractions

Cores acquired by a remanufacturer are typically highly variable in quality. Even if the expected fractions of the various quality levels are known, then the exact fractions when acquiring cores are still uncertain. Our model incorporates this uncertainty in determining optimal acquisition decisions by considering multiple quality classes and a multinomial quality distribution for an acquired lot. We derive optimal acquisition and remanufacturing policies for both deterministic and uncertain demand. For deterministic demand, we derive a simple closed-form expression for the total expected cost. In a numerical experiment, we highlight the effect of uncertainty in quality fractions on the optimal number of acquired cores and show that the cost error of ignoring uncertainty can be significant. For uncertain demand, we derive optimal newsboy-type solutions for the optimal remanufacture-up-to levels and an approximate expression for the total expected cost given the number of acquired cores. In a further numerical experiment, we explore the effects of demand uncertainty on the optimal acquisition and remanufacturing decisions, and on the total expected cost.     

授权制造下碳交易对制造/再制造影响及协调机制研究

在授权制造下,为分析碳交易对制造/再制造供应链影响和研究供应链协调机制,基于授权制造分别构建由一个原始制造商和一个再制造商参与的分散决策博弈模型和集中决策博弈模型,对比分析政府碳交易政策对两种决策模式最优解影响,并针对制造商分散决策导致的边际损失问题,给出固定授权费的协调机制。研究主要得到:无论分散决策还是集中决策,当碳交易价格大于某一阈值时,碳交易不仅可以降低两种产品对环境的影响,还增加消费者剩余;分散决策时,在碳交易下原始制造商可以通过降低单位授权再制造费用来增加利润;原始制造商和再制造商可以签订固定授权费的契约来协调供应链利润。     

零售商价格领导权结构下考虑专利保护的闭环供应链定价策略

很多零售商常处于其所在供应链的主导地位,针对零售商具有价格领导权并且考虑专利保护的闭环供应链进行分析,运用博弈理论得到了零售商、原制造商和再制造商的最优策略,以及最优策略关于再制造成本节约的变化规律。研究表明:随着再制造成本节约的增加,最优单位专利许可费和废旧产品回收价格逐步增加,最优产品批发价格和销售价格逐步降低,并通过数值算例表明:零售商、再制造商和供应链系统的利润逐步增加,原制造商的利润逐步减少。     

Optimal policy and holding cost stability regions in a periodic review inventory system with manufacturing and remanufacturing options

In this paper a periodic review inventory model with finite horizon and remanufacturing, manufacturing options is studied. It is assumed that demand and cost parameters are constant and a sufficiently large quantity of used products is available at the beginning of the horizon. The model is studied within the class of policies with given remanufacturing and manufacturing set up and the optimal policy is obtained within this class. The policy specifies the period of switching from remanufacturing to manufacturing (switching period), the periods where remanufacturing and manufacturing activities take place and the corresponding lot sizes. An explicit formula for the cost function and some of its properties are established. Based on these, an algorithm which partitions the set of holding cost parameters into subsets, computes the optimal policy and constructs its corresponding stability regions on every such subset is proposed.