不确定环境下的再制造闭环物流网络优化

考虑废旧产品回收数量、回收质量、再生产品需求量的不确定性以及废弃处理中心的选址等多重因素,构建单产品、多周期的再制造闭环物流网络优化设计模型,运用云遗传算法来确定物流网络中各设施的数量、位置、规模以及各设施间的合理物流分配量,使得在整个运营周期的净收益最大。通过算例来验证该模型的有效性。     

Joint optimisation of price,warranty and recovery planning in remanufacturing of used products under linear and non-linear demand,return and cost functions

We investigate joint optimisation of remanufacturing, pricing and warranty decision-making for end-of-life products. A novel mathematical–statistical model is proposed where decisions involve pricing of returned used products (cores), degree of their remanufacturing, selling price and the warranty period for the final remanufactured products. The virtual age reliability improvement approach is chosen to model the upgrading of the cores to higher quality levels. We consider price- and warranty-dependent demand, price- and age-dependent return, and age-dependent remanufacturing cost in the model development. Both linear and non-linear forms of these functions are investigated. First, under some restrictive conditions of upgrade level and age distribution of received cores, special cases of the problem, which can be solved using a recently developed non-linear optimisation solver, are presented. We also implement a particle swarm optimisation algorithm for the solution of the original problem when all the restrictive assumptions are dropped. Finally, numerical experiments and sensitivity analysis are presented to address different aspects of the model and the solution approaches.     

Performance analysis of a hybrid system under quality impact of returns

In this paper we analyze a hybrid system that meets the demand with remanufactured or new products. In the remanufacturing stage there are uncertainties in the quality of remanufactured products, return rates and return times of returned products. These uncertainties affect raw material order quantities, processing times and material recovery rates. In the study returned products are classified by considering quality uncertainties. According to this classification remanufacturing processing times, material recovery rates, remanufacturing costs and disposal costs are determined. In order to analyze the effect of uncertainties in return quality a simulation model is constructed by using the ARENA simulation program. Our analysis denotes that under different cost scenarios quality based classification of returned products brings significant cost savings. The numerical analysis indicates that a cost improvement of more than 8% is achieved when return rates are high.     

碳交易环境下再制造企业生产及减排投资决策

基于碳限额交易政策,对再制造企业生产和减排投资决策进行研究.在碳交易环境背景下,利用非线性凸优化理论,首先分析不减排投资时再制造企业的最优生产决策,然后研究再制造企业对生产新产品或再制造品减排投资时的情形.通过比较,探讨再制造企业进行减排投资时制造/再制造策略的调整,并分析减排投资对社会福利各因素(包括再制造企业利润、消费者剩余和环境影响)的影响.研究表明:对新产品(再制造品)减排将导致新产品(再制造品)产量的增加和再制造品(新产品)产量的降低;减排投资使再制造企业利润和消费者剩余均增加,但是环境影响(碳排放总量)则取决于单位再制造的碳排放量.最后,通过算例分析验证了以上结论.     

Remanufacturing and pricing decisions with random yield and random demand

Remanufacturing is creating considerable benefit to industry and community, but the uncertainties in both supply and demand sides bring significant difficulty to the production and marketing management of remanufactured products. This paper considers the remanufacturing and pricing decisions when both the remanufacturing yield and the demand for remanufactured products are random. Two typical sequential decision strategies are explored: First-Remanufacturing-Then-Pricing (FRTP) and First-Pricing-Then-Remanufacturing (FPTR). The optimal remanufacturing quantity and selling price of the remanufactured product are developed for each strategy, under negligible salvage value and shortage penalty. We also conduct a numerical study to investigate the scenario where the salvage value and shortage penalty are non-negligible, and explore the parameter sensitivity of the systems. We find that FRTP strategy is more preferable for low remanufacturing cost, market-price sensitivity, and variance of demand randomness, and for high shortage penalty, salvage value, and variance of remanufacturing yield; while FRTP strategy is more preferable for the complementary situation.     

Assessing the benefits of remanufacturing option under one-way substitution and capacity constraint

In this article, we investigate the profitability of remanufacturing option when the manufactured and remanufactured products are segmented to different markets and the production capacity is finite. A single period profit model under substitution is constructed to investigate the system conditions under which remanufacturing is profitable. We present analytical findings and computational results to show profitability of remanufacturing option under substitution policy subject to a capacity constraint of the joint manufacturing/remanufacturing facility.     

再制造/制造系统集成物流网络扩展模型研究

研究了再制造／制造系统集成的物流网络扩展模型，给出了其选址一分配模型．该模型特点是：网络结构为闭环网络；正向物流中统筹考虑再生品和新产品的物流分配，再生品和新产品不能相互替代；解决了新建装配厂、存储批发商及拆解中心的选址问题．     

再制造/制造系统集成物流网络模糊机会约束规划模型

在再制造/制造(R/M)系统集成物流网络中,回收产品的数量具有不确定性.根据这一特点,将各消费区域废旧产品的回收数量看成是模糊参数,提出了该集成物流网络的模糊机会约束规划模型.通过把模型中模糊机会约束清晰化,将模型转化为确定性的混合整数规划模型.利用实例数据,针对不同的置信水平对模型进行分析,其结果为该集成物流网络的设计提供了依据.     

Optimal distribution channel strategy for new and remanufactured products

The market for remanufactured products is large and growing rapidly, accelerated by the widespread popularity of internet sales and online auctions. Whereas extant remanufacturing research focuses primarily on such operations management issues in collecting of end-of-life products, remanufacturing technologies, production planning, and inventory control, we consider an operations-marketing interaction issue by identifying the optimal channel structures for marketing new and remanufactured products. Specifically, based on observations from current practice, we consider three channel strategies a dominant manufacturer can adopt: (1) marketing both new and remanufactured products through an independent retailer; (2) marketing the remanufactured products through the independent retailer, while controlling the new product sales by using its own online channel; (3) marketing the remanufactured products through the manufacturer-owned online channel, while selling new products through the independent retailer. Our results show that the manufacturer prefers to differentiate new and remanufactured products by opening a direct online channel, no matter how the system parameters change. However, which type of products (new or remanufactured) the manufacturer should sell through the online channel depends on the cost saving from remanufacturing, the customer’s acceptance of remanufactured products and the online inconvenience cost. Furthermore, this paper shows that, compared with channel strategy I where the manufacturer sells both new and remanufactured products through an independent retailer, this dual channel strategy benefits the end consumers, but might do harm to the retailer and the total supply chain in some situations.     

考虑政府补贴及环境设计的再制造闭环供应链生产决策

在外包及授权再制造模式下,研究考虑政府补贴及制造商环境设计的再制造闭环供应链生产决策问题.构建4种闭环供应链决策模型,分析政府补贴及环境设计水平对制造商与再制造商竞合关系、闭环供应链绩效以及环境的影响.研究发现,制造商可以通过调节单位再制造外包费或专利许可费实现与再制造商共享政府补贴,因此政府不同补贴策略不会对闭环供应链最优生产决策及绩效产生影响.政府补贴与消费者对再制造产品的认知程度,并不总是有利于提高制造商环境设计水平,但均有助于促进再制造产品销售.制造商总是有动机进行环境设计,而再制造商只有在环境设计能为再制造产品带来更多成本节约时,才有动力接受制造商的环境设计方案.相比于授权再制造,制造商及再制造商均在外包再制造下获得更多的利润.另外,政府补贴与环境设计并不一定总能起到减少产品环境总影响程度的作用.     

A heuristic solution procedure for the dynamic lot sizing problem with remanufacturing and product recovery

Here we discuss the lot sizing problem of product returns and remanufacturing. Let us consider a forecast of demands and product returns over a finite planning horizon — the problem is to determine an optimal production plan. This consists of either manufacturing new products or remanufacturing returned units, and in this way meets both demands at minimum costs. The costs of course are the fixed set-up expenses associated with manufacturing and/or remanufacturing lots and also the inventory holding costs of stocks kept on hand.In addition to showing that a general instance of this problem is NP-Hard, we develop an alternative mixed-integer model formulation for this problem and contrast it to the formulation commonly used in the literature. We show that when integrality constraints are relaxed, our formulation obtains better bounds. Our formulation incorporates the fact that every optimal solution can be decomposed into a series of well-structured blocks with distinct patterns in the way in which set-ups for manufacturing and remanufacturing occur. We then construct a dynamic programming based heuristic that exploits the block structure of the optimal solution. We also propose some improvement schemes as well. Finally, our numerical testing shows that the heuristic performs very well as intended.     

跨区域市场条件下品牌商再制造决策研究-----基于抵御平行进口商市场入侵的视角

针对一个品牌商和一个平行进口商组成的分销系统,探讨消费者对平行进口产品和再制造品感知质量存在差异情况下企业的最优产品决策,通过建立无再制造与再制造两种情形下的平行进口商市场入侵模型,分析品牌商再制造和平行进口的相互作用.研究表明,不管消费者对再制造品的感知质量如何,品牌商再制造可有效降低平行进口商的灰市投机行为;平行进口商的市场入侵会促进品牌商再制造;当再制造成本节约程度较小时,消费者对再制造品的感知质量越高,平行进口产品售价越低,平行进口量越小,平行进口商利润也越低.     

A production/remanufacturing inventory model with price and quality dependant return rate

Inventory management of produced, remanufactured/repaired and returned items has been receiving increasing attention in recent years. The available studies in the literature consider a production environment that consists of two shops. The first shop is for production and remanufacturing/repair, while the second shop is for collecting used (returned) items to be remanufactured in the first shop, where demand is satisfied from producing new and from remanufacturing/repairing returned items. Numerical and analytical results from these developed models suggested that a pure (bang–bang) policy of either no waste disposal (total remanufacturing) or no remanufacturing (pure production and total disposal) is the best strategy, while the mixed strategy (a mixture of production and remanufacturing) is the optimum case under certain limited assumptions. In practice, the quality of the returned items and the purchasing price that reflects this quality is what usually governs a collection (or return) policy of used items. Unlike those available models in the literature, this paper suggests that the flow of returned items is variable, and is controlled by two decision variables, which are the purchasing price for returned items corresponding to an acceptance quality level. Deterministic mathematical models are presented for multiple remanufacturing and production cycles.     

A production–inventory model with remanufacturing for defective and usable items in fuzzy-environment

This paper investigates a production–remanufacturing system for a single product over a known-finite time horizon. Here the production system produces some defective units which are continuously transferred to the remanufacturing unit and the constant demand is satisfied by the perfect items from production and remanufactured units. Remanufacturing unit uses the defective items from production unit and the collected used-products from the customers and later items are remanufactured for reuse as fresh items. Some of the used items in the remanufacturing unit are disposed off which are not repairable. The remanufactured units are treated as perfect items. Normally, rate of defectiveness varies in a production system and may be approximated by a constant or fuzzy parameter. Hence, two models are formulated separately with constant and fuzzy defective productions. When defective rate is imprecise, optimistic and pessimistic equivalent of fuzzy objective function is obtained by using credibility measure of fuzzy event by taking fuzzy expectation. Here, it is assumed that remanufacturing system starts from the second production cycle and after that both production and remanufacturing units continue simultaneously. The models are formulated for maximum total profit out of the whole system. Here the decision variables are the total number of cycles in the time horizon, the duration for which the defective items are collected and the cycle length after the first cycle. Genetic Algorithm is developed with Roulette wheel selection, Arithmetic crossover, Random mutation and applied to evaluate the maximum total profit and the corresponding optimum decision variables. The models are illustrated with some numerical data. Results of some particular cases are also presented.     

Acquisition and pricing strategies in hybrid manufacturing-remanufacturing systems

There are two typical cases of acquisition and remanufacturing in a closed-loop supply chain: The third party remanufacturer (3PR) and the original equipment manufacturer (OEM) separately acquire and remanufacture used products. The used products have different qualities, and they can be classified for acquisition in reality. In this paper, under the grading acquisition mode, we compare the acquisition strategies of used products and the pricing strategies of new products and remanufactured products in different manufacturing-remanufacturing systems. Then we further study the impact of the timing of remanufacturing on the profit and the environment. From an environmental perspective, the 3PR is willing to acquire and remanufacture used products at the best grade, whereas the OEM may choose more grades. The latter can reduce environmental impact. From an economic perspective, as long as the total cost of acquiring and remanufacturing used products does not exceed the threshold, remanufacturing can bring more profit for the OEM than only selling new products. Moreover, when consumers’ preference for remanufactured products is relatively high, and the total cost of acquisition and remanufacturing does not exceed the threshold, the OEM can engage in remanufacturing business before the new products exit from the market.     

考虑政府补贴的新产品与再制造产品定价模型

在有限财政预算下,政府对再制造产品进行补贴,以促进再制造产品的生产和销售.基于此,首先建立政府对制造商进行生产补贴的三层决策模型,该模型中制造商与新产品销售商和再制造产品销售商进行Stackelberg博弈,同时两个销售商之间通过Bertrand博弈确定各自的销售价,通过对解的分析,揭示生产补贴对批发价、销售价以及销售量的影响,并通过与无补贴销售量的比较,进一步给出政府补贴提升再制造产品销量的根本原因;然后给出对再制造产品销售商进行销售补贴下的三层模型,证明销售补贴与生产补贴在影响销售价格、销售量方面的等价性;接着讨论集中决策供应链中新产品与再制造产品销售的二层决策模型,比较集中决策供应链与分散决策供应链再制造产品的销售量高低并分析其原因,指出政府倾向于优先补贴的供应链类型;最后给出一个算例,分析不同类型供应链中再制造产品销售量对参数的敏感性.     

Dynamic co-opetitive approach of a closed loop system with remanufacturing for deteriorating items in e-markets

This study examines the dynamic economics of closed loop supply chains (CLSCs) that incorporate remanufacturing by developing analytical models under both cooperative and competitive policies in electronic markets. Specifically, this investigation presents the multi-variable profit-maximization problem and performs equilibrium analysis using a co-opetitive approach. Additionally, this study undertakes dynamic joint decisions for both brand-new and like-new versions of deteriorating items in a remanufacturing CLSC. The analytical results demonstrate that the dynamic co-opetitive decision depends on the potential size of the market for brand-new products, manufacturing and remanufacturing costs of the original equipment manufacturer, remanufacturing cost of the third-party independent operator, and intensity of competition between different products in the market.     

Neuro-fuzzy approach to forecast returns of scrapped products to recycling and remanufacturing

Forecasting of scrapped products to recycling poses severe problems to recycling and remanufacturing companies due to uncertainties in timing and quantities of returns. In this paper an extended forecasting method to provide prognoses for return values (amount and time) of scrapped products to recycling is presented. The suggested model is based on relevant influencing factors and product life cycle data and has been applied to a case study (photocopiers) for evaluation and usability. The approach employs a simulation study, the design of a fuzzy inference system for the forecasting of the return in a determined planning period and the design of a neuro-fuzzy system for the forecasting of return values with respect to time.     

Pricing strategy in a dual-channel and remanufacturing supply chain system

This article addresses the pricing strategy problems in a supply chain system where the manufacturer sells original products and remanufactured products via indirect retailer channels and direct Internet channels. Due to the complexity of that system, agent technologies that provide a new way for analysing complex systems are used for modelling. Meanwhile, in order to reduce the computational load of searching procedure for optimal prices and profits, a learning search algorithm is designed and implemented within the multi-agent supply chain model. The simulation results show that the proposed model can find out optimal prices of original products and remanufactured products in both channels, which lead to optimal profits of the manufacturer and the retailer. It is also found that the optimal profits are increased by introducing direct channel and remanufacturing. Furthermore, the effect of customer preference, direct channel cost and remanufactured unit cost on optimal prices and profits are examined.     

Production planning optimization for manufacturing and remanufacturing system in stochastic environment

This article studies a single item dynamic lot sizing problem with manufacturing and remanufacturing provisions. The demands and returns are considered as both stochastic and deterministic. There are two inventories recoverable and serviceable inventory. We developed a dynamic programming based model with objective to determine the quantities that have to be manufactured or re-manufactured at each period in order to minimize the total cost, including production cost, holding cost for returns and finished goods, and backlog cost. Also, unit production cost is also taken as variable in case of deterministic case. Finally, a numerical example for each of deterministic and stochastic model is worked out to illustrate how the model is applied and to prove its feasibility.