供应链库存商业信用协调的研究

本文研究由一个供应商和多个客户构成的以供应商主导的两级供应链,建立了以平均库存成本为目标函数的供应链供需同步库存模型。为了保证合理的收益分配,促进各成员加入供需合作的积极性,在模型中引入了商业信用机制,由供应商给予客户商业信用期而产生的机会成本(或利益)来平衡各成员间的利益。理论分析显示该模型存在最佳订货次数和最佳生产时间间隔,使供应链的总平均库存成本最小。最后利用算例分析和敏感性分析验证了商业信用的有效性。     

O2O在线回收企业再售策略研究

研究了O2O在线回收企业再售策略选择问题。研究发现:当制造商单位产品生产成本和处理商单位产品回收价格较低时,在线回收企业采取全部再售策略;当处理商单位产品回收价格居中时,在线回收企业采取部分再售策略;当处理商单位产品回收价格较高时,采取无再售策略。相对无再售行为的传统第三方回收而言,再售策略下O2O在线回收企业利润较优,故在线回收企业有动力进行再售,并且再售策略下消费者剩余优于传统第三方回收,而制造商利润降低。此外,全部再售策略下在线回收企业废旧品回收量优于传统第三方回收,有助于提升产品利用率,保护环境。     

下料问题与运输问题联合优化建模

本文研究了考虑子材运输的标准一维下料问题。建立了由生产商负责运输时,标准一维下料与运输协调优化整数规划模型,最小化母材使用成本,子材库存成本及子材运输成本。采用拉格朗日松弛技术对有关约束进行松弛和模型分解,设计基于序列规则和FFD规则的混合启发式算法求解模型。该算法由两部分组成,分别用于求解标准一维下料子问题和卖方运输子问题。通过随机产生的1800个算例,验证模型合理性与算法的有效性。与基于列生成法的两阶段算法解进行比较,平均总成本降低了17.57%,表明集成算法优于两阶段算法。     

An integrated production and inventory model for a whole manufacturing supply chain involving reverse logistics with finite horizon period

This paper proposes a model and solution method for coordinating integrated production and inventory cycles in a whole manufacturing supply chain involving reverse logistics for multiple items with finite horizon period. A whole manufacturing supply chain involving reverse logistic consists of tier-2 suppliers supplying raw materials to tier-1 suppliers, tier-1 suppliers producing parts, a manufacturer which manufactures and assembles parts from tier-1 suppliers into finished products, distributors distributing finished products to retailers, retailers selling products to end customers and a third party which collects the used finished products from end customers, dissembles collected products into parts, and feed the parts back to the supply chain. In this system, we consider a finite horizon period. A mathematical model for representing the behaviors of the system is developed. Solution methods based on decentralized and a combination of decentralized and centralized decision making process, referred to as the semi-centralized decision making process, are proposed to solve the model while the centralized decision making process is solved by a mixed integer nonlinear programming method. A numerical example is used to demonstrate the model and the solutions based on the three types of the coordination.     

Simultaneous production and logistics operations planning in semicontinuous food industries

The production and logistics operations planning in real-life single- or multi-site semicontinuous food industries is addressed in this work. A discrete/continuous-time mixed integer programming model, based on the definition of families of products, is developed for the problem in question. A remarkable feature of the proposed approach is that in the production planning problem timing and sequencing decisions are taken for product families rather than for products. However, material balances are realized for every specific product, thus permitting the detailed optimization of production, inventory, and transportation costs. Changeovers are also explicitly taken into account and optimized. Moreover, alternative transportation modes are considered for the delivery of final products from production sites to distribution centers. The efficiency and the applicability of the proposed approach is demonstrated by solving to optimality two industrial-size case studies, for an emerging real-life Greek dairy industry.     

第三方回收商领导型两级闭环供应链的回收与定价策略

与一般废旧产品的回收产品再制造相比,废弃电子电器产品回收拆解后需要兼顾产品与零部件再制造,从而减少电子电器产品对环境的污染,推进资源的重复利用。为了探讨第三方回收商的回收与定价策略对供应商和制造商的影响,本文构建由单一供应商、制造商和第三方回收商组成的两级再制造闭环供应链,建立Stackelberg博弈模型,研究两级再制造情形下和仅产品再制造情形下回收商的有效回收比例、回收定价和回收努力程度等决策,并对两种再制造情形下供应链各成员的决策与收益进行对比分析。研究发现：对于回收商而言,回收数量、有效回收比例的增加有助于回收商获得更多的额外收益。如果在仅产品再制造情形下的有效回收比例较大,回收商的决策和收益主要取决于无效零部件的回收价。当无效零部件的回收价较低时,回收商在仅产品再制造情形下的决策和收益更优;反之,回收商在两级再制造情形下的决策和收益更优。对于其他供应链成员而言,两种再制造策略都能够降低供应商和制造商的定价,促进市场需求的增加。具体而言,不同的再制造策略对批发价、零售价和市场需求的影响与有效回收比例和无效零部件的回收价密切相关。     

A model for reverse logistics entry by third-party providers

Reverse logistics has become an important entity in the US economy. Nonetheless, many companies are not capable of or are unwilling to enter the reverse logistics market. Such reluctance appears to be attributed to lack of knowledge of reverse logistics. This paper reviews current industry practices in reverse logistics. Specifically, we examine the issues and processes that an organization has to address to engage in the reverse logistics business. A reverse logistics decision-making model is developed to guide the process of examining the feasibility of implementing reverse logistics in third-party providers such as transportation companies. The purpose of this model is to help those companies who would like to pursue reverse logistics as a new market. A field study was conducted with a larger US transportation company to validate the proposed model.     

电子商务环境下合作采购效益分析

合作采购是一种重要的企业间电子商务应用模式,成功实施合作采购需要供应链成员的积极参与。本文针对供应商采取的两种批发价定价策略,比较分析了协调成本对买主间合作采购动力及其总体采购成本的影响。其结果表明,只要协调成本较小,买主便具有合作采购动力,且无论供应商采取固定价格策略还是采取数量折扣策略,都存在一个协调成本临界值,当协调成本小于该临界值时,合作采购将同时减少买主与供应商的总体成本;当协调成本大于该临界值时,则总有一方的总体成本在合作采购中增加。     

3PL参与的时变需求变质品三级供应链模型

随着现代物流业的发展,企业将一些业务如运输等外包已经成为参与当今市场竞争的一种手段和趋势,因此考虑包含第三方物流服务提供商（3PL）的供应链更具有现实和理论意义。但是现有文献很少考虑3PL对包含时间因素的变质品供应链模型的影响。基于此,本文建立了一个包含3PL的时变需求变质品三级供应链模型,并运用动态博弈理论求解了该模型的分散式下的均衡解。研究表明与制造商单独承担运输费用相比,由3PL承担运输费用使得产品的订货周期缩短,订货量减少。通过对比分散式决策和集中式决策下的最优解,研究发现考虑系统总体利润情况下,集中式决策的方式不能使该供应链达到协调。最后给出算例验证结论的正确性。     

考虑第三方物流竞争的第四方物流运输与库存外包决策

第四方物流在物流外包中的主导地位和第三方物流在提供服务时基于配送频率的竞争对物流外包产生重要影响。针对这一问题,本文建立基于价格、配送频率和需求分配比例的三阶段非合作动态决策模型和库存运输联合优化模型(ITIO)来分析4PL主导的业务外包和3PL之间的竞争,通过对比两个模型来分析决策权对个体和系统绩效的影响,并用算例验证了文章的结论。研究表明,在3PL同质且需求分配比例为0.5时,三阶段非合作动态决策模型的配送频率比ITIO最优值小29%,库存持有成本比ITIO最优值高41%,物流配送成本比ITIO最优值小21%,总成本比ITIO最优值大9%。库存运输联合优化模型虽然具有一定成本优势,但是其过分强调协调不利于3PL之间的竞争和提高。     

闭环供应链中互联网回收平台合作推广研究

考虑单个制造商，单个网络零售商和单个第三方回收商组成的闭环供应链系统，网络零售商在销售产品、推广零售平台的同时,利用自身知名度向消费者宣传推广第三方回收商的互联网回收平台，制造商选择是否分摊零售商和回收商的推广成本，文中分三种情形研究供应链成员的最优决策，并进行了对比分析。研究表明：制造商分摊推广费用比不分摊推广费用的效果好；制造商分摊网络零售商的推广费用比分摊第三方回收商的推广费用的推广效果好。     

产品回收逆向物流网络优化设计模型

为了在传统正向物流网络基础上扩建产品回收逆向物流网络,基于混合整数线性规划方法建立了一种单产品、有能力限制的产品回收逆向物流网络优化设计模型,据此确定物流网络中各种设施的数量和位置,并在由此构成的各条物流路径上合理分配物流量,以使各种设施的投资和运营成本之和最小。给出了提高模型求解效率的Benders分解算法,并通过算例验证了模型和算法的有效性。     

关税与成本变动下零售商主导的跨境双渠道供应链定价决策

构建了零售商为Stackelberg领导者的跨境供应链博弈模型,通过引入关税、国际运输成本等因素并分析关税变动对跨国供应链产品定价和各成员利润的影响。结果表明：随着产品关税的增加,国内制造商产品A批发价格会增加、产品A直销价格和境外制造商产品B批发价格会减少,而关税变动对零售商定价决策的影响与消费者价格敏感系数有关;本国加征关税会使得国内制造商利润增加、境外制造商利润减少,而关税增加对零售商利润影响与消费者价格敏感系数有关：只有当消费者价格敏感系数较大时,本国关税上调才会使得国内零售商利润增加;随着境外产品B国际运输成本的增加,产品A、B批发价格会减少,而产品A、B零售价格都会增加,供应链中各成员利润都会减少。     

Production quantity allocation for order fulfilment in the supply chain: a neural network based approach

In the current global business environment, it is very important to know how to allocate products from the producer to buyers (or distributors). If products are not appropriately distributed due to absence of an effective allocation policy, the producer and buyers cannot expect to increase customer satisfaction and financial profit. Sometimes some buyers can order more than the actual demand due to inappropriately forecasting customer orders. This is the big obstacle to the effective allocation of products. If the producer can become aware of buyers’ actual demands, it is possible to realise high-level order fulfilment through the effective allocation of products. In this study, new allocation policies are proposed considering buyers’ demands. The back propagation algorithm, one of the learning algorithms in neural network theory, is used to recognise actual demands from the previous buyers’ orders. After excluding surplus demands included in buyers’ demands, products are allocated to buyers according to one of the existing allocation policies depending on the company's decision. In the numerical examples, new allocation policies reducing buyers’ surplus demands outperform previous allocation policies with respect to average amount of backorder.     

物流服务供应链中基于期权契约的能力协调

不同于产品供应链,物流服务供应链作为能力链,其协调手段只能通过服务能力的调整与优化来实现。在Stackelberg主从博弈下提出一种基于期权契约的协调机制来研究集成商与分包商物流能力的订购与投资决策问题,并对协调机制效果及供应链期望额外利润的分配进行数值检验和结论分析。研究结果表明,所设计的期权契约可实现物流服务供应链完美协调,并提高双方的期望利润。而且,物流服务供应链实现协调时,期权契约参数--期权价格与期权执行价格之间存在负相关关系,而作为契约核心决策要素的期权价格必须在一个合理的范围内。     

A Heuristic Algorithm for the Capacitated Multiple Supplier Inventory Grouping Problem

This paper presents and solves a model for the multiple supplier inventory grouping problem, which involves the minimization of logistics costs for a firm that has multiple suppliers with capacity limitations. The costs included in the model are purchasing, transportation, ordering, and inventory holding, while the firm's objective is to determine the optimal flows and groups of commodities from each supplier. We present an algorithm, which combines subgradient optimization and a primal heuristic, to quickly solve the multiple supplier inventory grouping problem. Our algorithm is tested extensively on problems of various sizes and structures, and its performance is compared to that of OSL, a state-of-the-art integer programming code. The computational results indicate that our approach is extremely efficient for solving the multiple supplier inventory grouping problem.     

基于资源共享和温度控制的生鲜商品多中心车辆路径优化问题

针对生鲜商品多中心共同配送优化研究在资源共享和温度控制有效结合方面存在的不足,提出研究集成资源共享和温度控制的生鲜商品多中心车辆路径优化问题。首先,结合生鲜商品的易腐性和配送过程的及时性特征,构建了包含生鲜商品多中心间的运输成本、配送成本、车辆温控成本、违反时间窗惩罚成本、生鲜商品价值损失和车辆租赁成本的物流运营成本最小和配送车辆使用数最小的双目标优化模型。然后,设计了结合生鲜需求客户地理位置、需求商品温控区间和时间窗约束的K-means多维聚类算法,进而提出一种TS-NSGA-II算法,该算法设计了禁忌搜索算法(TS)和非支配排序遗传算法(NSGA-II)间有效的选择性赋予机制,进而增强了解空间的搜索和寻优能力,并通过与MOGEA和MOPSO算法的对比分析,进一步验证了模型和TS-NSGA-II算法的有效性。最后,通过实例分析探讨了不同资源共享模式和温控区间的多中心车辆路径优化方案,研究结果可为生鲜商品物流配送企业进行资源共享模式选择和温控区间设计提供方法支撑和决策支持。     

A vendor–purchaser economic lot size problem with remanufacturing

In this paper, we study a closed-loop supply chain in which a single purchaser orders a particular product from a single vendor and sells it on the market. A certain fraction of used items return from the market back to the purchaser, who is responsible for collecting and returning them to the vendor. In addition to manufacturing new items, the vendor is able to remanufacture the returns into as-good-as-new items which are subsequently used to serve market demand. Our framework features the conventional joint economic lot size (JELS) model extended to include the return flow of the used items. In line with the assumptions of the JELS model, we assume a deterministic constant demand for the product. The fraction of used items returning from the market is assumed to depend on the purchaser’s collection effort. To stimulate the returns, the vendor may offer the purchaser a transfer payment per item returned. The questions addressed by this study pertain to the optimal centralised control of this closed-loop supply chain, to the individually optimal policies of its members, and to the coordination within this supply chain under a decentralised control. In particular, we show that the transfer payment alone cannot coordinate the supply chain under consideration and may even fail to do so when combined with a two-part tariff—which is otherwise known to coordinate the corresponding forward supply chain. Our numerical study, though, has revealed that the combined contract is capable of substantially reducing the coordination deficit. We also introduce a novel three-part tariff which is shown to enable supply chain coordination in combination with the transfer payment.     

The value of acquisition price differentiation in reverse logistics

The quality of returned products may vary greatly, depending on their previous usage. Since the remanufacturing of products in good condition is more economically rewarding for the remanufacturer—and since even for non-remanufacturable products the value that can be extracted from their parts or materials may depend on the products’ quality—it seems logical to acquire used products of different quality levels at different prices. However, acquisition price differentiation requires the product quality to be revealed, i.e. the products are graded before their actual acquisition. We observe two different approaches in current practice. The first one is a decentralized system with several collection sites to which the customers can bring their used products. After a short grading procedure, they receive a specific acquisition price offer for their products, which they can accept or decline directly. The second setting is a reverse logistics system with a centralized grading facility. The final grading is conducted after shipping the used products to this specific facility. Motivated by these empirical observations, we compare the two strategies with the help of a continuous approximation model. We derive analytical expressions for the optimal pricing and network density decision and show that, in addition to the other factors discussed in the literature, acquisition price differentiation can be a reason for decentralizing the reverse logistics network, if the product quality is uncertain. Furthermore, we illustrate our results with a numerical example.     

突发疫情环境下考虑订单释放时间的零售物流配送路径优化研究

“新冠肺炎”疫情突发严重危及了人们的生活安全，而物流保障在疫情防控、保民生活、稳定社会方面却起到了重要支撑作用。以保证民生的零售物流配送为背景，本文研究考虑订单释放时间的车辆路径优化问题，以配送完工时间与运输成本的加权之和最小为目标，构建了线性规划模型,并设计了改进的迭代局部搜索求解算法。该算法采用基于多种邻域结构和改进的US算法的局部搜索过程以增强算法的寻优能力，通过引入大路径和最优分割过程获得高质量的初始解和打破机制以增强算法的搜索效率。同时，提出一些性质用于拉格朗日松弛算法，为本文研究问题提供高质量的下界。最后，数值实验部分通过求解标杆算例和文中算例验证了模型和算法的有效性，并对订单释放时间和模型参数进行灵敏度分析，结果表明本文模型和算法能够为零售物流配送的效率提升和成本控制提供有效的决策支持。