“批对批”策略下关于供应商管理库存机制的一个探讨

本文考虑了一个由单供应商和单采购商构成的两级供应链系统,在供应商采取"批对批"策略下,引入VMI后将对供应链系统以及各渠道成员利益带来的影响.我们发现,渠道权力配置对VMI作为供应链企业间合作机制的有效性存在重要影响.在采购商占主导地位的渠道中,当系统参数满足一定条件时,引入VMI后可以同时降低供应商和采购商总成本,从而VMI可以成为供应商和采购商之间的有效合作机制.但在供应商占主导地位的渠道中,引入VMI必将增加供应商的总成本,此时VMI不是供应商和采购商之间的有效合作机制.     

基于前景理论的报童问题: 考虑回购和缺货惩罚

在前景理论的框架下,通过引入回购和缺货惩罚因素研究了3 种情形下报童最优订货量问题; 通过证明给出了特定参数条件下前景理论报童最优订货量与经典报童最优订货量的明确关系,进一步给出了前景理论最优订货量与回购价格及缺货惩罚价格的函数变化关系．最后,通过数值分析说明了研究结论.     

联合经济批量模型中的损失补贴与利益分配问题研究

针对单供应商和单采购商构成的供应链系统,分采购商占主导地位和供应商占主导地位两种情形,讨论了采购商的最优订货决策与供应商的最优生产决策,以及它们合作情形下的系统最优决策,给出了采购商和供应商各自独立决策与联合决策下,它们各自的成本函数以及供应链系统的总成本函数.最后,通过比较独立决策与联合决策下采购商和供应商的成本函数,分析了联合经济批量模型中的损失补贴与利益分配问题.     

不可分物品的在线采购拍卖竞争策略研究

本文研究网络环境下不可分物品的在线采购拍卖竞争策略。首先给出采购商的离散需求曲线，并设计出一个确定性的采购拍卖策略，然后对该策略进行竞争分析，得到一个较优的竞争比。该竞争比与采购商对供应商投标上下限的估计及采购量有关，采购商可以通过合理估计欲购品价格的上下限来降低竞争比。     

考虑随机市场需求的双渠道供应链风险补偿策略研究——从质量与价格竞争视角

在由两个供应商和单个零售商构成的二级双渠道供应链系统中，分析了随机市场需求以及供应商之间同时存在价格与质量竞争的情形下的双渠道供应链协调问题。在供应链集中决策、无风险补偿及有风险补偿三种情境下，构建了基于质量和价格的风险补偿模型并求得纳什均衡解。研究结果表明：存在可行的需求风险补偿策略使得供应链达到协调水平，并且需求风险补偿策略对零售商更加有利；在需求风险补偿策略下，需求风险补偿价格与其对应批发价格正相关，与其产品质量水平负相关；价格竞争程度对零售商订货量具有负向影响作用，对供应链总利润影响作用随着竞争程度增加而减弱，质量竞争程度对零售商订货量和供应商产品质量水平具有正向影响作用，对供应链总利润影响呈倒U型关系；需求风险补偿策略能够激励零售商的订货行为，强化价格竞争程度和质量竞争程度对供应商订货量和供应链总利润的影响；在供应链系统中双渠道营销模式下的供应链总利润要优于单渠道营销模式下的供应链总利润。本文结论不仅详细剖析了风险补偿策略对双渠道供应链协调的影响关系，也理清了价格与质量竞争对各方行为策略的影响机理。     

两级供应链中供应中断情形下零售商转运策略

考虑由两个供应商和两个零售商组成的两级供应链系统,且两个供应商以一定概率发生供货中断,基于供应商供货发生中断的四种情形,分别对零售商实施相互转运策略、单向转运策略和不转运策略下建立最优订货决策模型。从理论上比较了三种策略下零售商期望利润和订货量高低,并分析相互转运和单向转运策略下零售商期望利润和订货量与转运价格、转运成本之间的关系,最后运用算例进行验证,同时分析了三种策略下,供应中断概率和其它主要参数的变化对零售商期望利润和最优订货量的影响。     

基于多属性逆向拍卖的博弈分析

对只有一个采购商和多个供应商之间进行的单轮多属性逆向拍卖建立了非合作博弈模型,分析得出投标具有最高质量和最短交货期属性的供应商能够获得最大利润,同时能够给采购商带来最大剩余.因此采购商并不会根据最低投标价格,而是根据投标质量和交货期的最优组合来选择新的供应商.然后,把投标价格看作投标质量和交货期的函数,推导出了供应商的最优投标价格策略,并进一步推出纯子博弈纳什均衡策略.最后,通过算例验证了模型的有效性,并指出采购商在利用多属性逆向拍卖进行采购之前,应该对供应商资格进行审核来决定最后能够参与到拍卖中的供应商数目.     

Excel在最优订货量决策上的应用

存货管理的关键环节是最优订货量的确定。最优订货量可以使包括采购成本、订货成本及储存成本在内的存货相关总成本达到最低。本文根据经济订货量理论,运用Excel2007制作符合多种假定前提的最优订货量模型。以直观动态的表格数据及可调节图形方式显示多种条件下存货的最优订货量结论。     

考虑退货价格的易逝品供应链协调性研究

考虑由一个制造商和一个零售商组成的供应链,制造商以批发价格为零售商提供一种易逝品,零售商再以零售价格将产品销售给顾客;零售商以一定的退货价格回收顾客的退货产品,制造商对零售商的顾客退货产品及销售季节结束后的剩余产品进行回收,零售商的退货价格不仅对产品的需求有影响,而且对顾客的退货率也产生影响.在这样的条件下,建立了需求不确定环境下顾客退货及制造商回收的模型,结果表明,制造商简单回收顾客的退货产品和销售季节结束后的剩余产品并不能实现供应链协调,而基于回馈与惩罚策略的制造商回收策略能够实现供应链的协调.最后,给出了供应链协调下的模型优化方法,并以数值实例计算了易逝品供应链协调下的最优退货价格和最优订货量,并分析了各种参数变动对最优退货价格、最优订货量和集中式供应链最优利润的影响.     

基于返回策略的供应链网络竞争绩效研究

针对由多个供应商和多个零售商组成的结构可变的供应链网络,分别在零售商之间基于订货量以及价格两种竞争方式下,分析了供应商均不采用返回策略、部分采用返回策略以及均采用返回策略六种情景下供应链网络的竞争绩效。研究发现当零售商基于订货量竞争时,供应商采用协调策略对于其零售商客户及供应链均为占优策略,零售商更换供应商的成本将会影响供应商的收益以及采用协调策略的积极性;当零售商之间基于价格竞争时,返回策略在一定程度上仍能够激励零售商增加订货量,且对供应链渠道的利润绩效及其稳定性均具有一定的改善作用。     

Combined Pricing and Portfolio Option Procurement

In this paper, we study a single‐product periodic‐review inventory system that faces random and price‐dependent demand. The firm can purchase the product either from option contracts or from the spot market. Different option contracts are offered by a set of suppliers with a two‐part fee structure: a unit reservation cost and a unit exercising cost. The spot market price is random and its realization may affect the subsequent option contract prices. The firm decides the reservation quantity from each supplier and the product selling price at the beginning of each period and the number of options to exercise (inventory replenishment) at the end of the period to maximize the total expected profit over its planning horizon. We show that the optimal inventory replenishment policy is order‐up‐to type with a sequence of decreasing thresholds. We also investigate the optimal option‐reservation policy and the optimal pricing strategy. The optimal reservation quantities and selling price are shown to be both decreasing in the starting inventory level when demand function is additive. Building upon the analytical results, we conduct a numerical study to unveil additional managerial insights. Among other things, we quantify the values of the option contracts and dynamic pricing to the firm and show that they are more significant when the market demand becomes more volatile.     

Dynamic Pricing and Inventory Management with Regular and Expedited Supplies

We consider a periodic‐review inventory system with regular and expedited supply modes. The expedited supply is faster than the regular supply but incurs a higher cost. Demand for the product in each period is random and sensitive to its selling price. The firm determines its order quantity from each supply in each period as well as its selling price to maximize the expected total discounted profit over a finite or an infinite planning horizon. We show that, in each period if it is optimal to order from both supplies, the optimal inventory policy is determined by two state‐independent thresholds, one for each supply mode, and a list price is set for the product; if only the regular supply is used, the optimal policy is a state‐dependent base‐stock policy, that is, the optimal base‐stock level depends on the starting inventory level, and the optimal selling price is a markdown price that decreases with the starting inventory level. We further study the operational impact of such supply diversification and show that it increases the firm's expected profit, reduces the optimal safety‐stock levels, and lowers the optimal selling price. Thus that diversification is beneficial to both the firm and its customers. Building upon these results, we conduct a numerical study to assess and compare the respective benefit of dynamic pricing and supply diversification.     

带学习效应的双渠道供应链库存策略研究

针对具有学习行为的双渠道供应链问题,本文研究了两种分销渠道并存下的最优库存策略。有限计划期内,分销商通过传统销售和在线销售来满足下游顾客的需求。两种分销渠道下的销售单价为时变不减线性函数,当系统中各周期的生产订购固定成本以一定的概率具有学习效应行为时,分别建立了非变质产品生产存贮问题的混合整数约束优化模型以及易变质产品存贮问题的无约束混合整数优化模型,所建立模型的目标为极大化分销商总利润函数。对于这两类模型,通过分析其最优解的性质,利用将生产订购次数松弛为连续变量的技巧证明了最优解存在的唯一性。给出了最优策略的求解方法并比较了两类模型最优利润函数值的大小。最后通过数值算例对上述模型进行了验证,数值结果表明当供应链系统中存在学习效应行为时,该系统能够获得更多的利润。     

考虑成本和收益净现值的确定性存储决策模型研究

净现值是企业决策中需要考虑的重要宏观经济因素.本文建立了考虑成本和收益净现值的连续时间有限时段确定性库存系统的最优存储和定价决策模型,证明了给定价格下最优策略中任意两个相邻订货周期之间的递推关系,分析了该关系的解析性质,并得出订货周期长度的上下限.在此基础上提出求解最优存储策略和最优价格的两步优化算法.最后通过数值算例对本文模型及结果做出说明.     

易变质产品在带运输时间的二级供应链中的订购策略研究

研究了带运输时间的易变质产品的二级供应链库存模型。在有限计划期内,为补充下游分销商发出的订单,上游制造商以一定的生产速率进行生产。由于产品运输给分销商时需要花费时间与成本,在开始一段时间内分销商的订单得不到及时补充,只有当制造商的库存量达到最大时,才将产品运输给分销商。目标就是确定最优订购策略使得整个系统的总成本最小。通过分析成本函数的特点,证明了2种特殊情形下最优解的存在及唯一性。最后通过算例验证了最优策略的有效性。     

多类顾客环境下报童模型中库存分配策略研究

考虑一个报童模型中多类顾客的库存分配问题,将顾客按照他们愿意支付价格的高低划分为不同级别。零售商在销售期初决定产品订货量,并在销售期内决定接受或者拒绝不同顾客的需求,以最大化销售期内的期望总利润。将销售期分成大量足够小的时间单位,通过建立一个反向Bellman动态规划方程,以优化每个时间单位内的库存分配策略,并得到了零售商最优的期初订货量。通过与没有库存分配策略下零售商的期望利润进行比较,算例分析得出库存分配策略可以大幅提高零售商的利润。这主要是因为通过库存分配可以使得零售商从高端顾客中获取更多利润,同时能够减小期初的订货量,以节约采购成本和库存持有成本。     

供应链融资结构视角下的零售商订购策略研究

本文引入供应链融资结构因素,在传统库存管理模型基础上,研究零售商在面临随机市场需求情形下考虑股权和债权等融资方式的订购策略,建立允许零售商延期支付的最优订购模型,利用最优化理论与方法得到了该模型的最优解,证明了最优解的存在性和唯一性,并分析了债权融资比例、价格成本比例系数、销售价格、订货周期、回购价格、进货价格、缺货成本、库存成本、以及融资利率等因素对最优解的影响。进一步,通过数值示例深入探讨具体市场环境下零售商的最优订购量,并进行了敏感性分析。研究发现,债权融资比例、价格成本比例系数、进货价格、订购周期、库存成本与零售商订购量存在负相关关系;缺货成本、回购价格、销售价格与零售商订购量正相关。相关研究结论可以为零售商订购行为提供科学指导,并为其库存管理提供重要决策依据。     

Dynamic Pricing and Inventory Management with Dual Suppliers of Different Lead Times and Disruption Risks

It is common for a firm to make use of multiple suppliers of different delivery lead times, reliabilities, and costs. In this study, we are concerned with the joint pricing and inventory control problem for such a firm that has a quick‐response supplier and a regular supplier that both suffer random disruptions, and faces price‐sensitive random demands. We aim at characterizing the optimal ordering and pricing policies in each period over a planning horizon, and analyzing the impacts of supply source diversification. We show that, when both suppliers are unreliable, the optimal inventory policy in each period is a reorder point policy and the optimal price is decreasing in the starting inventory level in that period. In addition, we show that having supply source diversification or higher supplier reliability increases the firm's optimal profit and lowers the optimal selling price. We also demonstrate that, with the selling price as a decision, a supplier may receive even more orders from the firm after an additional supplier is introduced. For the special case where the quick‐response supplier is perfectly reliable, we further show that the optimal inventory policy is of a base‐stock type and the optimal pricing policy is a list‐price policy with markdowns.     

Optimal Policies for Selling New and Remanufactured Products

Because of environmental and economic reasons, an increasing number of original equipment manufacturers (OEMs) nowadays sell both new and remanufactured products. When both products are available, customers will buy the one that gives them a higher (and non‐negative) utility. Thus, if the firm does not price the products properly, then product cannibalization may arise and its revenue may be adversely impacted. In this paper, we study the pricing problem of a firm that sells both new and remanufactured products over a finite planning horizon. Customer demand processes for both new and remanufactured products are random and price‐sensitive, and product returns (also called cores) are random and remanufactured upon receipt. We characterize the optimal pricing and manufacturing policies that maximize the expected total discounted profit. If new products are made‐to‐order (MTO), we show that when the inventory level of remanufactured product increases, the optimal price of remanufactured product decreases while the price difference between new and remanufactured products increases; however, the optimal selling price of new product may increase or decrease. If new products are made to stock (MTS), then the optimal manufacturing policy is of a base‐stock policy with the base‐stock level decreasing in the remanufactured product inventory level. To understand the potential benefit in implementing an MTO system, we study the difference between the value functions of the MTO and MTS systems, and develop lower and upper bounds for it. Finally, we study several extensions of the base model and show that most of our results extend to those more general settings.     

Analysis of an EOQ inventory model with partial backordering and non-linear unit holding cost

In this paper, an economic order quantity inventory model is analyzed, considering that the unit cumulative holding cost has two significant components: a fixed cost which represents the cost of accommodating the item in the warehouse and a variable cost given by a potential function of the length of time over which the item is held in stock. Shortages are allowed and, during the stockout period, only a fraction of demand is partially backordered. The backordering cost includes a fixed cost and a cost linearly dependent on the length of time for which backorder exists. A solution procedure is developed for determining the optimal inventory policy. Moreover, to illustrate the effects of some parameters on the optimal policy and the minimum total inventory cost, a numerical study is developed.