Joint hybrid repair and remanufacturing systems and supply control

The control of a stochastic manufacturing system that executes capital asset repairs and remanufacturing in an integrated system is examined. The remanufacturing resources respond to planned returns of worn-out equipment at the end of their expected life and unplanned returns triggered by major equipment failures. Remanufacturing operations for planned demand can be executed at different rates and costs corresponding to different replacement and repair modes. The replacement components inventory is provided by an upstream supply with random lead times. The objective is to determine a control policy for both the supply and remanufacturing activities that minimises the average repair/replacement, acquisition and inventory/shortage total cost over an infinite horizon. We propose a suboptimal joint remanufacturing and supply control policy, composed of a multi-hedging point policy (MHPP) for the remanufacturing stage and an (s, Q) policy for the replacement parts supply. The MHPP is based on two inventory thresholds that trigger the use of predefined remanufacturing modes. Control policy parameters are obtained combining analytical modelling, simulation experiments and response surface methodology. The effects of the distribution, mean and variability of the lead time are tested and a sensitivity analysis of cost parameters is conducted to validate the proposed control policy. We also show that our policy leads to a significant cost reduction as compared to a combination of a hedging point policy (HPP) and an (s, Q) policy.     

Pricing and remanufacturing decisions in two competing supply chains

This paper considers the pricing and remanufacturing decisions in a duopoly market with two competing supply chains, which compete at both manufacturer and retailer levels. There are one manufacturer and one retailer in each supply chain, one manufacturer produces the new product directly from raw material, while the other manufacturer has incorporated a remanufacturing process for used product into the original production system. Based on different industry organisation structures and the chain members’ competing forms, five game decision models are established to explore the chain members’ optimal strategies on price and/or remanufacturing, and the corresponding equilibrium solutions are obtained. Finally, we carry out the sensitivity analysis through numerical studies of some key parameters for examining their influences on the pricing decisions and chain members’ maximum profits. On the basis of comparison and analysis, some managerial insights are derived.     

考虑回收品质量可控的再制造闭环供应链决策

研究回收品质量可控背景下的再制造闭环供应链决策问题。考虑质量投入与奖励函数2种控制变量对再制造过程中回收品质量的影响,构建集中决策与分散决策下制造商主导的Stackelberg博弈模型,采用逆向求解法求解2种决策条件下的模型最优解,并利用数值模拟分析回收品质量对各参数的影响。研究表明,相较于分散决策,联合决策具有更高的经济性收益性与风险敏感性;不论是分散决策或是联合决策,回收价、供应链企业利润等都与回收品质量呈正相关;消费者强烈的绿色偏好与回收价格偏好能够对供应链利润产生积极影响。     

考虑渠道权力结构和产品双重差异的再制造闭环供应链最优定价决策

针对具有不同渠道权力结构和回收拆解产品质量差异、新产品与再制造产品价格差异的再制造闭环供应链,主要研究其成员企业最优定价决策问题。构建了包含制造/再制造商、零售商、消费者和回收拆解商的三级再制造闭环供应链决策模型;采用Stackelberg主从博弈确定不同渠道权力结构下各成员企业的最优定价策略及其利润,并重点探讨废旧产品回收率τ、产品替代系数δ两个关键参数对它们的影响;将该决策模型应用到汽车发电机再制造闭环供应链案例。研究结果表明：1） 对于3种渠道权力结构,当制造/再制造商和零售商为主导者时,其自身利润和再制造闭环供应链总利润均最大;而当回收拆解商为主导者时,其自身利润和总利润却最小;2） 随着τ和δ的提高,单位新产品与再制造产品的最优批发价、最优零售价均增加,单位废旧产品的最优回收价则降低;制造/再制造商和零售商的利润下降,回收拆解商的利润上升,导致再制造闭环供应链的总利润呈U形。研究能够为各成员企业的最优定价决策提供有效支持与参考。     

Joint effects of remanufacturing channel design and after-sales service pricing: an analytical study

We conduct an analytical study on remanufacturing channel design and after-sales service pricing, which jointly affect the sustainability and profitability of the supply chain. We model a supply chain with one manufacturer and one independent retailer. The manufacturer, as the Stackelberg game leader, engages in remanufacturing to take advantage of production cost savings. The collection of the used products can be carried out by either the manufacturer or the retailer. After-sales service, for example, extended warranty, is offered with the product and is sold separately. The service provider can be either the manufacturer or the retailer. We use game theoretic models to answer an important research question: How do remanufacturing and after-sales service jointly affect channel selection decisions? We explore the benefits of joint decision making in terms of remanufacturing efficiency and after-sales service performance. We find that it is most efficient for the retailer to collect the used product for remanufacturing and to offer after-sales service, because the retailer simultaneously makes decisions regarding remanufacturing and after-sales service and thus reduces double marginalisation in the supply chain. We also demonstrate numerically how the costs of collecting used products and providing after-sales service impact channel selection decisions.     

Product quality choice in two-echelon supply chains under post-sale liability: insights from wholesale price contracts

This paper considers a two-echelon supply chain consisting of an upstream manufacturer (M) and a downstream Retailer (R) who transact intermediate products via a wholesale price contract. The supply chain provides an experience good to unit-demand consumers. M is liable for the harm caused by its products in a low quality state. A two-stage game model is built to describe how the supply chain operates. With the equilibrium and under certain assumptions, this paper finds that (1) in spite that post-sale product liability positively affects the wholesale price, M’s quality level, the contracted quantity and supply chain members’ profitability are independent of it; (2) when liability-related factors and M’s quality improvement efficiency change, the wholesale price serves as a medium for M and R to mutually share the ex ante expected liability cost, the demand loss caused by the ex ante expected consumer harm and the ex ante quality-improving cost; (3) in response to changes in liability-related factors, the quality performance is in conflict with the financial performance for both M and R, but this conflict disappears in the presence of a change in quality improvement efficiency. Managerial insights are also discussed.     

Pricing decisions in closed-loop supply chains with marketing effort and fairness concerns

We investigate closed-loop supply chains (CLSCs) under four reverse channel structures where a central planner, a manufacturer (M), a retailer (R) or a third party (T), respectively, serves as the collector of used product and demand depends on R’s marketing effort. We derive supply chain profitability under both the centralised and decentralised CLSCs and furnish the optimal marketing effort, collection rate and pricing decisions for the supply chain members. We then extend the base models along two directions: the first extension incorporates R’s distributional fairness concerns into the M collection model and the second extension considers potential recycle cost advantages by R and T compared to the M collection model.     

Reverse channel selection decisions with a joint third-party recycler

In recent years, Internet-based firms have been increasingly engaged in recycling used products, taking advantage of economies of scale by serving a number of manufacturers. However, most studies on the recycling channel of remanufacturing to date only consider the case of a single manufacturer in a closed-loop supply chain. To address this gap, we develop a Stackelberg game model and show that the joint third-party (J3P) collection mode serving multiple manufacturers may outperform individual retailer- and manufacturer-managed modes, as opposed to existing findings considering a single manufacturer. It is optimal for manufacturers to authorise a large-scale J3P to collect used products. In addition, we show that the J3P can design a two-part tariff contract for the manufacturers to overcome the double marginalisation and collective action problems in decentralised supply chains. Our results provide guidance for enterprises and the government on recycling decisions in the era of a network economy.     

Dynamic product acquisition in closed loop supply chains

We consider a closed-loop supply chain where demand can either be satisfied by manufacturing new products or by buying back used products from customers and upgrading their functionality by remanufacturing. A joint buy-back pricing and manufacturing–remanufacturing decision model at the operations–marketing interface is presented that allows for dynamic parameters, e.g. product life cycles and seasonal aspects. The model allows the identification of beneficial opportunities for buying back and storing used products for immediate and future recovery. We present a new deterministic, dynamic, continuous-time optimisation model, derive necessary and sufficient optimality conditions, and develop a solution algorithm to find the cost-minimising manufacturing and remanufacturing policies as well as buy-back strategies for used products based on Pontryagin's Maximum Principle. It is shown that, in general, an optimal policy will include time intervals where returns are acquired so as to synchronise demand and remanufacturing, where returns are acquired and stored for future remanufacturing, and intervals where demand is satisfied by a mix of manufactured and remanufactured products. Furthermore, we discuss several reactive and proactive acquisition and remanufacturing heuristics and show under which conditions they are optimal. The findings are illustrated by numerical examples.     

Hybrid manufacturing/remanufacturing lot-sizing and supplier selection with returns,under carbon emission constraint

This paper addresses a lot-sizing problem in manufacturing/remanufacturing systems. The studied system is a single manufacturing line where both regular manufacturing and returns remanufacturing processes are carried out, with different set-up costs for each process. We consider also a returns collection phase from customers/distributors with deterministic returns quantities at each period of the planning horizon. The environmental aspect is assumed in this study by considering a carbon emission constraint for the manufacturing, remanufacturing and transportation activities. A mixed integer programming model to minimise the management cost and meet the customer’s needs under different manufacturing constraints is proposed. Otherwise, An adaptation of the well-known Silver and Meal (SM) heuristic and two hybrid method approaches (HM1 and HM2) providing approximates solutions are developed. The mixed integer model was tested on Cplex (Software optimizer), and the obtained results were compared with the ones provided by the adapted heuristic SM and the hybrid methods. The numerical analyses show that hybrid methods provide good-quality solutions in a moderate computational time. The proposed model establishes a collegial and an integrated process that sets values, goals, decisions and priorities along the considered supply chain while taking into account the environmental aspect.     

授权模式下OEM和第三方的生产和回收定价竞争策略

假设第三方再制造商（第三方）需要向原始设备制造商（OEM）缴纳授权费才能进行回收再制造，OEM和第三方在正向供应链销售市场与逆向供应链回收市场均存在竞争。文章建立了以双方闭环供应链利润最大化为目标带约束条件的古诺博弈模型，通过K-T条件求出第三方部分再制造和第三方完全再制造两种情形下两企业最优的产品生产量以及废旧品回收价格。最后分别通过解析方法和数值算例分析了单位授权费等参数对决策变量和最优利润的影响。     

Using game theory for analysing pricing models in closed-loop supply chain from short- and long-term perspectives

Closed-loop supply chain (CLSC) management is an environmental approach to supply chain management that aims to prevent hazardous material from entering the nature by means of creating a reverse flow. This paper studies the short- and long-term behaviour of agents in implementing the appropriate collecting strategy in a two-echelon CLSC. In short-term, based on the Stackelberg game, several novel pricing models for different collecting strategies are proposed and compared. Then, the optimal policies of the pricing decisions are determined for each model. The long-term behaviour of companies in implementing collecting process is examined by evolutionary game theory and the most stable strategy is selected. Furthermore, a numerical example is presented to compare the different collecting structures. Finally, a managerial insight is provided to indicate the effect of key parameters such as remanufacturing rate, marketing elasticity and government subsidies on selecting the appropriate strategy.     

On measuring company performance within a supply chain

Emerging research strengthens the connection between supply chain performance and a company's financial performance (D’Avanzo, R., Von Lewinski, H. and Van Wassenhove, L. N., 2003. The link between supply chain and financial performance. Supply Chain Management Review, November/December, 40–47). The focus on integrating functional internal processes has expanded to include the need for integrating these with external processes of business partners (Edwards, P., Peters, M. and Sharman, G., 2001. The effectiveness of information systems in supporting the extended supply chain. Journal of Business Logistics, 22(1), 1–27). This need for enterprise efficiency is compelling companies to review, to identify, and to adopt supply chain initiatives. This research investigates the use of common measurement metrics in an attempt to determine which one(s) are most useful for measuring performance as companies implement SCM practices. For firms that were engaged in SCM we found inventory and cycle time to be the most significant metrics.     

Supply chain network design with multi-time-period stochastic demands for optimizing dual objectives on economic and environmental factors

ABSTRACT

Traditional supply chain management focuses on operational and financial factors, such as improving operational efficiency and reducing cost. Since global warming has become critical, researchers and managers of the supply chain have paid more attention to environmental issues. With the environmental factor, the complexity in designing an optimal supply chain network essentially increases. This research considers a multi-objective (minimal total cost and CO₂ emissions) supply chain network design with environmental factor (SCNDEF), which includes the features of multiple echelons, stochastic demands, production/storage capacity, environmental investment, and multiple time periods. In order to help managers make decisions about the SCNDEF, this research performs sensitivity analyses to investigate the effect of key parameters, such as customers’ satisfaction level and limits on CO₂ emissions, on the performance of the supply chain network. Numerical examples are given to verify the proposed methodology. The results show that a good SCNDEF can not only improve the performance of the entire supply chain but also achieve sustainable environmental protection. These research findings are intended to serve as practical reference for industry.     

Integrated production–distribution planning in two-echelon systems: a resilience view

Global supply chains are increasingly exposed to operational and disruption risks that threaten their business continuity. This paper presents a novel two-stage scenario-based mixed stochastic-possibilistic programming model for integrated production and distribution planning problem in a two-echelon supply chain over a midterm horizon under risk. Operational risks are handled by introducing imprecise (i.e. possibilistic) parameters while disruption risks are accounted for through stochastic disruption scenarios. The proposed model accounts for the risk mitigation options and recovery of lost capacities in an integrated manner. In the first stage, the structure of the chain and proactive risk mitigation decisions are determined, while the second stage specifies the recovery plan of lost capacities in addition to production and distribution plans. Considering extra capacities in the production facilities, backup routes for transportation links and pre-positioning of emergency inventory in distribution centres are considered as feasible options to improve the resilience level of the supply chain. We propose a new indicator for optimising the resilience level of the chain based on restoration of lost capacities. For the sake of robustness, the expected worst case of the second stage’s objective function is considered by utilising the conditional value at risk (CVaR) measure. The validation and applicability of the proposed model are examined through several numerical experiments.     

制造商主导下差别主体努力的闭环供应链决策研究

针对再制造节约成本和努力水平对闭环供应链成员回收决策产生影响的问题,构建制造商主导下M模式、R模式和T模式3种不同主体回收模式,利用Stackelberg博弈知识,建立模型,采用数学优化法求解闭环供应链废旧品回收过程中单位价格、回收数量以及回收商利润的最优值,运用对比分析法得出闭环供应链混合回收的最优决策。研究表明,再制造节约成本较大对主体回收均有促进作用;回收努力成本系数的增加,使节点企业利润和闭环供应链系统整体利润均呈现下降趋势,最终利用算例求解,检验结论的合理性。研究为供应链各个主体的最佳定价策略提供有效的参考。     

Modelling and solving spare parts supply chain network design problems

Spare parts are key operational assets in order to minimise unexpected equipment downtimes that may significantly impact a company’s results. The spare parts supply chain network supports the entire spare parts operations management and it is essential to achieve the planned goals. However, most of the traditional literature on spare parts management has not focused on the underlying supply chain network. Thus, this paper studies the integration of supply chain network design and control with traditional spare parts management. In particular, a generic network optimisation modelling structure is proposed, with simultaneous optimisation of warehouse locations and inventory control decisions, allowing minimising the total costs associated with the spare parts supply chain network. The generic model is specified based on three inventory control policies widely employed in the industry, which are suitable for managing a great variety of spare parts, i.e. (s, Q), (R, s, S) and (S-1, S). Furthermore, a solution approach is proposed based on Generalised Benders Decomposition. Finally, numerical results from a real-world application case in the process industry are shown and discussed.     

考虑政府补贴和不同回收渠道的再制造闭环供应链最优决策研究

为研究政府分别实施再制造补贴和回收补贴下不同回收渠道对再制造闭环供应链的决策影响,建立以制造商为领导者,零售商和回收商为跟随者的闭环供应链的Stackelberg主从博弈模型,对比分析两种补贴方式下不同回收渠道的最优定价和回收策略。结果表明,补贴金额的多少会降低产品价格和批发价,刺激消费,提高回收率,增加闭环供应链上所有参与方的利润,而与补贴类别无关;当存在双回收渠道时,回收商与零售商之间回收的竞争强度影响产品售价、回收率和制造商的利润,而回收转移价格仅与补贴类型有关。最后,通过实例分析探讨不同补贴与不同回收渠道对闭环供应链的影响。     

Dual channel closed-loop supply chain coordination with a reward-driven remanufacturing policy

This paper investigates a reward-driven policy, employed in a closed-loop supply chain (CLSC), for acquiring used products earmarked for remanufacture. Under the examined model, a single manufacturer sells products through a retailer as well as directly to end users in a forward supply chain. In the reverse supply chain, three different modes of collection are employed to capture used products for remanufacture: they are through a third party, directly by the manufacturer and from the retailer. Mathematical models for both non-cooperative and centralised scenarios are developed to characterise the pricing decisions and remanufacturing strategies that indicate individual and overall supply chain performance. Optimality of all the proposed models is examined with theory. To coordinate and achieve a win–win outcome for channel members, we proposed a three-way discount mechanism for the manufacturer. Extended numerical investigation provides insights on ways to manage an efficient reward-driven CLSC in a dual-channel environment.     

考虑回购和价格补贴契约的易逝品供应链协调机制

在随机需求的市场环境下,研究基于回购和价格补贴契约的易逝品供应链协调问题。分析了分散式供应链系统在没有协调情况下零售商的最优决策,以及在缔结回购和价格补偿契约下零售商的最优决策,并与集成式供应系统下的最优决策进行了比较,得出仅依赖系统各方成本结构的供应链完美协调的必要条件。算例分析验证了基于回购和价格补偿契约的随机动态规划模型能够反映易逝品分阶段采用不同营销策略的现实,同时也验证在不确定的市场环境下,供应商是缔结契约的积极倡导者,而零售商是缔结契约的积极响应者,通过缔结契约实现供应商和零售商的双赢。