基于PI的企业动态库存补货模型与算法

PI(physical internet)环境下的物流网络具有互联、开放和共享的特点,缺货的PI-枢纽或零售商可根据货源选择策略动态选择为其补货的供应商或PI-枢纽。为解决PI环境下库存补货问题,提出了IB-EB(installation-echelon)混合补货策略。以最小化库存补货成本为目标,补货量和再订购点为决策变量,构建了PI环境下的动态库存补货模型。针对该混合整数非线性规划模型,应用粒子群优化算法求解出多个补货预案,再将其带入仿真环境循环优化求解。最后,以中国航空器材进出口公司为例,验证了模型可解性及算法的可行性。结果表明PI环境下货源策略的选择对库存补货成本和补货策略具有十分重要的影响,为企业在不同补货条件下选择货源提供了参考依据。     

库存成本变化的VMI供应链协调

提出了库存成本变化的经济订货批量(EOQ)模型，基于该模型研究了库存成本变化时供应商管理库存(VMI)系统的最优协议问题。在该系统中，订货商和供应商达成缺货成本共担协议：当缺货发生时，供应商需要向订货商支付缺货补偿。订货商和供应商分散决策，订货商通过设计协议来减少其成本，而供应商通过制定补货决策来缩小自身成本。通过与传统系统和整合系统的比较，得出了库存成本变化时VMI系统的最优补货决策和缺货成本共担协议。采用数值算例验证了分析结果。结果表明，当且仅当供应商预期成本等于整合系统的最小总成本与固定缺货罚金之和时，VMI系统与整合系统具有相同的补货决策和系统绩效，即能够实现供应链协调。     

基于混合差分进化算法的联合补货-配送优化模型

本文综合考虑联合补货与配送决策,研究了随机需求、允许缺货环境下多企业多产品联合补货与配送集成优化模型,设计了混合差分进化算法(Hybrid Differential Evolution, HDE)对该模型进行求解,同时通过算例与遗传算法、标准的DE算法进行了比较,证实HDE算法高效且稳定;另外,设计了一个先补货再配送的两阶段优化模型,对比优化结果发现采用供应链协同时补货成本较高,配送成本较低,且总成本较低。最后,对相关参数进行了敏感性分析,发现需求率和库存维持成本的变动对总成本的影响远远大过次要订货成本对总成本的影响。     

库存共享和服务水平限制下三级分销网络侧向转运模型与算法

侧向转运是库存共享的一种方式,一方面会减少库存成本,另一方面又会因转运而增加运输成本,针对这一问题考虑不同时间窗W^k的服务水平产生的服务水平的分级,构建三级分销网络中基于库存共享与时间服务水平限制的批量订货模型,分销网络模型中包含一个制造商、一个RDC、m个DC、n个客户。其中客户的需求相互独立且服从泊松分布,DC的订货提前期服从指数分布。首先,建立了基于时间服务水平限制的分销网络系统总成本最小化模型,并将再购点、订购批量等库存参数作为同时作为决策变量,以达到三级备件分销网络的成本优化;其次,根据问题和模型的特点对所建的模型开发了基于采用贪婪增加算法的求解思想求解问题,以便给管理者提供决策参考并通过降低利润的方式增加效益和资源利用率;最后,通过中航材集团推行的“航材共享”项目作为算例分析,将三个分销区域与机场群组成的备件分销系统进行建模分析,验证了本文模型的有效性,成本优化的显著性。研究结果表明,三级分销网络中,RDC采用连续盘点的（Q,R）补货策略、DC采用（Q,R,H）的补货策略时系统总成本与普遍采用的定期盘点策略和连续盘点中的One-for-One订货策略成本相比,DC之间的库存共享策略能有效降低整个系统的成本,例如,在案例研究中发现成本降低约为30%。     

基于差分进化算法的运输容量约束下有数量折扣的模糊联合补货模型研究

针对采购管理中广泛存在的不确定性,将单位库存成本和可变订货成本视为模糊变量,构建了运输容量约束下有数量折扣的模糊联合补货模型,此模型属于NP-hard问题,目前缺乏可靠的全局优化求解算法。在选取梯级平均综合表示法对总成本去模糊的基础上,设计了基于自适应混合差分进化算法的求解方法,并通过算例验证了此模糊联合补货模型的有效性和求解算法的全局优化能力。     

基于Supply-Hub运作模式的供应商协同补货策略研究

Supply-Hub作为整合管理不同供应商零件库存的供应链节点,同时也承担了供应物流协同运作管理平台的功能.本文考虑加工-装配系统中存在的因一种零件缺货而造成其它配套使用的零件滞存的问题.研究了一种基于Supply-Hub运作模式,在供应商之间可以共享补货及库存信息的条件下,供应商协同补货策略,并与供应商分散补货模式下的基本补货模型进行比较分析.通过算例验证了该补货策略能有效降低供应链系统成本以及供应商成本.     

供应链分销系统优化及仿真

研究多个制造商多个分销商组成的分销系统, 综合考虑库存成本、订货成本、运输成本和 缺货成本, 建立了较为全面的分销网络成本模型, 以分销商满足市场需求时的服务水平作为优 化问题的约束条件, 求解成本优化问题. 然后, 给出了求解上述最优订货量的方法, 并用仿真方 法分析了价格参数及订货比例系数对总成本的影响. 结论表明: 随着运价参数b 的降低, 总成 本下降幅度较大; 分销商在地理位置方面的特征, 会影响分销商在不同供应商之间的最优订货 比例, 该比例不是越大越好, 也不是越小越好, 最优比例是居中的某个数值.     

基于需求预测的短生命周期产品订货策略研究

本文针对短生命周期产品的特点,考虑与需求因子相关的库存短缺拖后和无形变质,根据缺货时间点、订货时间点与产品到达成熟期的时间点之间的关系,建立基于短生命周期产品需求预测的3种订货策略模型:乐观订货策略,悲观订货策略和中庸订货策略模型,对模型进行了分析求解,对最优解的存在性进行了证明.然后根据实际销售数据进行需求预测和算例分析,分析各因子对于总库存成本、订货量、短缺拖后量、销售损失量以及最优订货策略的影响.最后通过订货策略分析,分析各因子对于最优订货策略的影响,并将它们划分为3种订货策略影响因子,分析结果可以指导企业在不同因子水平情况下如何调整订货策略,以降低总库存成本.     

考虑订货协调成本与数量折扣的改良品供应链水平协调

在单个供应商与多个销售商构成的二级改良品供应链中，销售商们采用联合补货方式不仅可以分摊订货成本，而且由于订货批量的增加从而更易获得供应商提供的数量折扣合同。建立多个销售商在独立补货与联合补货中的利润水平函数，推导联合补货优于独立补货的充要条件。将销售商之间的联合补货行为转化成多人合作博弈问题，证明博弈具有的基本性质，设计基于博弈核心的利润分配方法。通过数值算例和敏感性分析验证了文中所构建模型的正确性。     

基于CPFR的多产品分销系统库存优化模型

本文中的分销系统由生产多种产品的多个制造商,一个地区分销中心DC,多个零售商所组成,系统采用基于CPFR来确定订货临界点,并且在假设DC和零售商都实行连续性盘点的(R,Q)库存控制策略,提前期为随机变量,零售商需求为泊松分布的前提下,以整个分销系统的库存成本最小化为目标函数,以DC和零售商的多产品服务水平为约束条件,通过确定最佳订货批量,建立了此多产品分销系统的库存优化模型,从而达到有效控制库存的目的.     

A hybrid approach to the study of CPFR implementation enablers

Collaborative planning, forecasting and replenishment (CPFR) is one of the most important but also one of the most difficult collaborative strategies in supply chain management. CPFR has been well documented in past research as providing significant benefit to those that implement it well. It has also been noted that CPFR uptake has been significantly lower than initially expected. The main reason for this slow uptake is the general recognition that successful implementation of CPFR is not a trivial task and the fact that it inflicts dramatic changes to the ‘usual’ way of doing business. Based on the premise that CPFR has significant positive potential for supply chain collaboration, the motivation of this paper is to review CPFR enablers and to develop a model which addresses the most significant ones. To complete this task, a hybrid modelling approach integrating fuzzy extended analytical hierarchy process and interpretive structural modelling is proposed. The model developed is based on an identified gap by the automotive sector and embeds expert opinion, from two separate industrial groups in the automotive sector through the use of workshops. Although potential success factors for CPFR implementation can vary across somewhat between differing supply chains, the results maintain wider general applicability due to the many common issues across sectors. The paper highlights the need for decision-makers to be aware of the most influential enablers prior to a CPFR implementation project and to understand the relationships between these enablers.     

The Impact of E‐Replenishment Strategy on Make‐to‐Order Supply Chain Performance

This research investigates the impact of electronic replenishment strategy on the operational activities and performance of a two‐stage make‐to‐order supply chain. We develop simulation‐based rolling schedule procedures that link the replenishment processes of the channel members and apply them in an experimental analysis to study manual, semi‐automated, and fully automated e‐replenishment strategies in decentralized and coordinated decision‐making supply chain structures. The average operational cost reductions for moving from a manual‐based system to a fully automated system are 19.6, 29.5, and 12.5%, respectively, for traditional decentralized, decentralized with information sharing, and coordinated supply chain structures. The savings are neither equally distributed among participants, nor consistent across supply chain structures. As expected, for the fully coordinated system, total costs monotonically decrease with higher levels of automation. However, for the two decentralized structures, under which most firms operate today, counter‐intuitive findings reveal that the unilateral application of e‐procurement technology by the buyer may lower his purchasing costs, but increase the seller's and system's costs. The exact nature of the relationship is determined by the channel's operational flexibility. Broader results indicate that while the potential economic benefit of e‐replenishment in a decentralized system is substantial, greater operational improvements maybe possible through supply chain coordination.     

Book reviews

This paper is aimed at developing and testing a methodology to evaluate the most appropriate collaboration level within a given supply chain. In particular, the proposed methodology is conceived for logistic networks belonging to the consumer packaged goods industry, e.g. the grocery industry, and it consists of: (i) identifying an approximation of collaboration, (ii) representing through such approximation the different options among collaborative planning forecasting and replenishment (CPFR), vendor management inventory (VMI) and loosely collaborative approach (LCA); (iii) using a simulation-based decision support system to select the best collaboration level. The proposed methodology has been applied to a real-life supply chain in the food and beverage industry. Results conclude that the methodology proposed here proved useful in facing the problem of collaboration level definition among the nodes of a consumer packaged goods logistic network.     

基于信息共享增值机制的供应链需求均衡优化

文章将供应商、经销商追求利益最大化目标与用户需求的相互作用表述为一个双层规划问题。其中,上层规划为供应商与经销商的零售价格优化模型,下层为用户购买与需求均衡模型,分别表现为寡头、垄断、社会最优等不同信息共享机制。文章设计灵敏度分析算法和迭代方法求解和优化供应链需求均衡问题。     

基于Credit期权的集群式供应链采购模型及算法分析

集群式供应链是以产业集群为运作平台的供应链系统。本文先在单供应商-单采购商采购模型的基础上,建立了多供应商-多采购商的集群式供应链分散式采购模型。在模型中通过采用柔性周期和Credit期权策略,构建了适合多频次、小批量、柔性、信任等特征的集群式供应链多供应商-多采购商Credit期权联合采购模型,并设计出针对模型的Enumeration算法。最后,通过算例分析了集群供应链Credit期权联合采购模型有效性。     

基于两种策略的四级供应链质量控制优化研究

考虑到供应链实际构成与四级供应链质量控制研究不足,本文运用stackblerg博弈分析模型,研究了由供应商、制造商、经销商与消费者组成的四级供应链产品质量控制问题。在考虑需求不确定性的基础上,分析制造商与经销商之间延期支付和货款首付比例两种策略对供应链产品质量控制水平的影响,通过运用最优化原理求解制造商和供应商的最优质量控制水平并对结果进行仿真模拟,结果显示：制造商与经销商之间非质量协调策略对供应链产品质量有间接协调作用;制造商提高经销商货款首付比例或缩短余款延期支付时间,不仅有助于提高自身产品加工质量控制水平,更有助于供应商原材料质量水平提高,制造商在运用两种策略时,必须同时考虑产品价格引致的消费者需求量的变化和质量控制对其他主体收益变化的影响。     

不确定环境下的Supply-hub协同补货决策

个性化需求与零部件创新使得产品需求和补货提前期不确定,对供应链补货决策和运行成本产生重要影响。将提前期不确定因素引入Supply-hub协同补货研究中,探讨提前期随机和需求不确定情况下,考虑零部件配套性的三供应商单制造商生产两定制产品的Supply-hub协同补货决策问题;提出了三种补货策略,以供应链运行成本最小化为目标,建立不同策略下的供应链补货模型并求解最优补货批量和供应链最小运行成本;发现三种补货策略均存在唯一最优补货批量,基于Supply-hub的两种协同补货策略和基于分散决策的供应商独立补货策略各有优势,但基于Supply-hub的批量及时间协同的补货策略恒优于基于Supply-hub的集中补货策略。最后,通过MATLAB进行算例分析验证结论,发现基于Supply-hub的批量及时间协同的补货策略能有效降低需求不确定性带来的成本增加风险;通用件的提前期波动对于供应链期望运行成本的影响要高于定制件提前期波动的影响,因此在进行供应链补货策略选择时更加关注通用件提前期。     

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.     

Managing Slow‐Moving Perishables in the Grocery Industry

We address the value of information and value of centralized control in the context of a two‐echelon, serial supply chain with one retailer and one supplier that provide a single perishable product to consumers. Our analysis is relevant for managing slow‐moving perishable products with fixed lot sizes and expiration dates of a week or less. We evaluate two supply chain structures. In the first structure, referred to as decentralized information sharing, the retailer shares its demand, inventory, and ordering policy with the supplier, yet both facilities make their own profit‐maximizing replenishment decisions. In the second structure, centralized control, incentives are aligned and the replenishment decisions are coordinated. The latter supply chain structure corresponds to the industry practices of company‐owned stores or vendor‐managed inventory. We measure the value of information and value of centralized control as the marginal improvement in expected profits that a supply chain achieves relative to the case when no information is shared and decision making is decentralized. Key assumptions of our model include stochastic demand, lost sales, and fixed order quantities. We establish the importance of information sharing and centralized control in the supply chain and identify conditions under which benefits are realized. As opposed to previous work on the value of information, the major benefit in our setting is driven by the supplier's ability to provide the retailer with fresher product. By isolating the benefit by firm, we show that sharing information is not always Pareto‐improving for both supply chain partners in the decentralized setting.     

基于分布式工厂的供应链二级分销网络生产计划优化模型

从供应链的集成和协作角度出发,提出了在多工厂、多分销商条件下二级分销网络生产计划制定的双层规划模型,模型考虑了二级网络中制造商和分销商之间的信息共享,从而降低了整个链上的费用。同时设计了启发式求解算法,并给出了一个数值例子。