An integrated retail space allocation and lot sizing models under vendor managed inventory and consignment stock arrangements

In this paper, we develop integrated retail shelf space allocation and inventory models for a single item with a stock dependent demand. The integrated models are developed for a supply chain operating under vendor-managed inventory (VMI) and consignment stock (CS) agreement. More precisely, the supplier is responsible for initiating orders on behalf of the retailer and decides about the size of each order, the quantity to be displayed on the shelves, and the reorder point. In addition, the supplier owns the stock at the retailer’s premises until it is sold. We develop mathematical models to assess the benefits accrued by both parties as a result of the adoption of VMI–CS partnership. Results from the numerical experimental study show that such partnership is more attractive to all supply chain members when the retailer provides a flexible display capacity. Moreover, the supplier can use his/her selling price and the maximum allocated shelf space as negotiation means to benefit from the partnership.     

A vendor managed inventory model under contractual storage agreement

Vendor managed inventory (VMI) is a supply chain partnership strategy that allows a supplier to place orders on behalf of its customers. This paper considers a supply chain composed of a single vendor and multiple retailers operating under a VMI contract that specifies limits on retailers' stock levels. We address the problem of synchronizing the vendor's cycle time with the buyers' unequal ordering cycles by developing a mixed integer non-linear program that minimizes the joint relevant inventory costs under storage restrictions. We also propose a cost efficient heuristic to solve the developed optimization problem. We conducted computational experiments to assess the reduction in the total supply chain costs resulting from relaxing the restriction of equal ordering cycles. It is found that the heuristic generates greater cost savings in cases of increased variability in retailers' demand and cost parameters.     

VMI for single-vendor multi-retailer supply chains under stochastic demand

This paper discusses how a vendor and multiple retailers interact in a vendor managed inventory (VMI) system under stochastic demand. It is assumed that the vendor replenishes all the retailers at the same time. The vendor replenishment cycle is taken to be an integer multiple of the retailer replenishment cycle. In case of a shortage at the vendor, the available stock is allocated to the retailers on the basis of equal stock out probability. Approximate expressions for minimizing the expected total cost for the VMI system have been developed. Various levers affecting the performance of the system have been analyzed. The validity of the approximate model has been tested through simulation.     

Analysing the effectiveness of vendor-managed inventory in a single-warehouse,multiple-retailer system

This paper considers a two-stage supply chain, consisting of a single warehouse and multiple retailers facing deterministic demands, under a vendor-managed inventory (VMI) policy. It presents a two-phase optimisation approach for coordinating the shipments in this VMI system. The first phase uses direct shipping from the supplier to all retailers to minimise the overall inventory costs. Then, in the second phase, the retailers are clustered using a construction heuristic in order to optimise the transportation costs while satisfying some additional restrictions. The improvement of the system's performance through coordinated VMI replenishments against the system with direct shipping only is shown and discussed in the comparative analysis section.     

供应链中分享真实信息的激励机制

展示了古诺竞争模型中一个供应商和多个零售商的3 阶段博弈模型, 并证实了如果零售商能真实地分享预测信息, 则供应商往往会获利, 而零售商的利润将下降. 分享信息时零售商会有动机透露较少的需求预测, 这种信息失真现象是各方利用私人信息获取自身利益的结果. 如果供应商和零售商分享信息前, 能够就相对利润率或利润达成协议, 则信息共享的阻碍因素和扭曲信息的动机会消失, 零售商将如实地分享信息, 双方都能够从信息共享的行为中获利.     

A genetic algorithm for the vendor-managed inventory routing problem with lost sales

This paper proposes a genetic algorithm (GA) for the inventory routing problem with lost sales under a vendor-managed inventory strategy in a two-echelon supply chain comprised of a single manufacturer and multiple retailers. The proposed GA is inspired by the solving mechanism of CPLEX for the optimization model of the problem. The proposed GA determines replenishment times and quantities and vehicle routes in a decoupled manner, while maximizing supply chain profits. The proposed GA is compared with the optimization model with respect to the effectiveness and efficiency in various test problems. The proposed GA finds solutions in a short computational time that are very close to those obtained with the optimization model for small problems and solutions that are within 3.2% of those for large problems. Furthermore, sensitivity analysis is conducted to investigate the effects of several problem parameters on the performance of the proposed GA and total profits.     

The impact of customer returns on decisions in a newsvendor problem with and without buyback policies

In this paper, we examine how customer returns influence the retailer's ordering decision, the manufacturer's wholesale price decision, and the profits of the manufacturer and the retailer, in a single‐period, stochastic demand (newsvendor) setting. When the manufacturer is a Stackelberg leader and the retailer is the follower, we also examine how to contract a buyback policy, where the manufacturer buys back both unsold inventory and customer‐returned products, so that both the manufacturer and the retailer are more profitable than if they operate independently. We also show how this work can be generalized to the case of multiple retailers.     

考虑线上线下零售商竞争的制造商双渠道定价策略

根据现有的不同电商销售平台模式,将制造商双渠道销售模式划分为自营模式、平台模式和混合模式.分析在制造商主导的双渠道供应链中,3种不同渠道模式下价格竞争系数和佣金比例系数对其他经济变量的影响,以及制造商的最优定价决策与渠道选择问题.通过模型和数值分析发现,在平台模式和混合模式中,当制造商保证佣金比例系数在一定范围内,制造商利润随佣金比例系数的增加而减少,传统零售商、网络零售商和供应链总利润随佣金比例系数的增加而增加.在3种渠道模式中,混合模式对传统零售商和制造商利润增加更有利,平台模式对网络零售商和供应链总利润增加更有利.     

Production and allocation policies in a two-class inventory system with time and quantity dependent waiting costs

This paper presents an integrated production and inventory allocation model in a two-echelon supply chain system. The higher echelon is a manufacturer, who produces a single commodity. The lower echelon consists of two types of major commodity distributors who might face stochastic or deterministic demands from multiple retailers. Our analytical model provides optimal decision policies that minimize total production and customer waiting costs from the manufacturer's perspective when there are time and quantity dependent customer waiting costs. We identify the value of the integrated policy and compare it with typical approximations such as aggregating the multiple demands or applying the single demand multiple times.     

双重补贴下考虑低碳商誉的供应链决策和协调

考虑低碳和回收补贴政策,对供应链中上游制造商碳减排和再制造,下游零售商低碳宣传共同提高产品低碳商誉的现实问题展开分析.将低碳商誉水平作为状态变量,构建非协同和协同情形下的微分博弈模型.通过对比分析,设计利润共享-低碳宣传成本共担的协调机制.研究表明:各情形下的低碳商誉水平均会随着时间逐渐达到稳定状态;双重补贴不仅能够激励制造商的低碳行为,还能有效提高产品低碳商誉和成员绩效,但是不会影响零售商的低碳宣传水平;非协同情形导致供应链效率的损失,协调时保持低碳宣传成本分担比例高于利润分享比例可有效改善低碳商誉水平.此外,制造商适当提高其成本分担比例有利于成员利润的改善.     

考虑产品替代的低碳供应链定价和政府财税

基于低碳经济背景,考虑由政府、制造商和零售商三方博弈构成的供应链,使用Stackelberg博弈和纳什均衡的分析方法求出模型的均衡解,并对比了零售商是否联合两种模式下的社会福利、制造商和零售商利润。结果表明：零售商联合情况下的零售商和制造商利润大于零售商非联合情形,同时产品需求量和社会福利与零售商非联合情形相同。高碳产品市场规模越大,社会福利、零售商和制造商利润会先下降后上升,低碳产品的生产成本增加,社会福利、制造商利润会下降,若零售商不联合,销售高碳产品零售商利润上升,销售低碳产品零售商利润下降,若零售商联合则零售商利润下降。     

Coordinating the ordering and advertising policies for a single-period commodity in a two-level supply chain

This study deals with the news-vendor problem to the case of a two-level supply chain consisting of one manufacturer and one retailer, and investigates the combined effects of the cooperative advertising mechanism, the return policy and the channel coordination. The manufacturer and the retailer could maintain the potential market size by making some marketing expenditures on some national brand names and invest in local advertising, but with diminishing returns. The decision problem facing the profit-oriented entities in the supply chain is to determine the optimal advertising and inventory policies for maximizing their own profit. Both the non-cooperative policy and the cooperative policy are formulated to offer structural and quantitative insights into the interplay between upstream and downstream entities of the supply chain. In addition, the implications of a profit-sharing mechanism based on achieving a win–win relationship of the channel members was also proposed.     

Profit sharing and firm performance in the manufacturer-retailer dual-channel supply chain

With the rapid development of e-commerce and the adoption of dual channels, increasingly manufacturers and retailers are implementing profit sharing strategies in order to improve channel coordination and supply chain performance. In this study, we focus on the strategic role played by profit sharing in a manufacturer-retailer dual-channel supply chain. We use a game theory approach to investigate this issue. We compare the expected profits that each supply chain player receives in a traditional retail system with the profits that can be achieved in a profit-sharing dual-channel system. Our results show that both the manufacturer and the retailer always benefit from a dual-channel profit-sharing strategy because of the incremental profit gains generated by the dual-channel strategy. Furthermore, the Nash (Econometrica 18:155–162, 1950) bargaining model is utilized to implement profit sharing for the manufacturer and the retailer to achieve their channel coordination. Based on our results, optimal market strategies are derived and probable paths of future research are identified.

考虑多类零售商的库存与运输VMI 集成策略

研究由单批发商多零售商构成的供应商管理库存(VMI)供应链,批发商向外部供应商订货,并为价格和缺货成本不同的零售商补货.首先构造解析模型以分析如何为多类零售商确定不同的库存分配策略;然后将这一最优的库存分配策略与最优的先到先服务(FCFS)策略进行比较,同时比较相应简化的库存分配策略和简化的FCFS策略.解析和算例结果表明,简化的库存分配策略总是优于简化的FCFS策略,而最优的库存分配策略大部分情况下优于最优的FCFS策略.     

An integrated approach for logistic and vendor managed inventory in supply chain

In this paper, a quaternary policy system towards integrated logistics and inventory aspect of the supply chain has been proposed. A system of multi retailers and distributors, with each distributor following a unique policy, will be analysed. The first policy is continuous time replenishment policy where the retailers’ inventory is replenished in every time interval. In the next three policies, inventory of the retailers will be replenished by some definite policy factors. The vendor managed inventory (VMI) system is used for updating the inventory of the retailers. An order-up-to policy (q, Q) is used for updating the inventory of distributors. Total erstwhile demands to the retailer will be used to determine the amount of inventory acclivity. Furthermore, the distributors will be sending the delivery vehicles to few fellow retailers who are shortlisted according to the policy, followed by the retailers and associated distributors. On the basis of random demand that the retailers are facing from end customers and the total demand that has incurred in the supply chain, products are unloaded to the selected retailers from the delivery vehicle. The path of the delivery vehicle is retrieved by dynamic ant colony optimization. In addition, a framework has been developed to measure the end-customer satisfaction level and total supply chain cost incorporating the inventory holding cost, ordering cost and the transportation cost. The framework has been numerically moulded with different settings to compare the performance of the quadruplet policies.     

Analyzing information-enabled stockout management under vendor-managed inventory

We develop a mechanism under vendor-managed inventory (VMI) by which a manufacturer provides an incentive contract to a retailer to convert lost sales stockouts into backorders. An incentive contract is required since the retailer’s efforts are not directly observable. We first show that when there are no limits on order quantities or inventory levels imposed on the manufacturer, the manufacturer will push inventory onto the retailer. The manufacturer minimizes the possibility for lost sales stockouts by maintaining high inventory levels at the retailer rather than by paying incentives to the retailer. However, modern information systems (IS), such as radio frequency identification (RFID), allow the retailer to monitor inventory at its premises and to enforce limits on order quantities. With strict limits on order quantities, the manufacturer will provide incentives to the retailer to convert lost sales stockouts to backorders. We analyze the conditions under which these incentive payments are likely to be highest.     

水产品供应商管理库存(VMI)模型的设计

供应商管理库存VMI（vendor managed inventory）技术是供应链管理理论出现以后提出来的一种新的库存管理模式，其主要目的是将供应链上的整体存货水平降到置低限度。结合水产品及其库存管理的特点，本文分析了水产品供应商管理库存（VMI）的基本特征，在此基础上构建了一个适用于水产品的VMI模型。     

Production and coordination decisions in a closed-loop supply chain with remanufacturing cost disruptions when retailers compete

This paper studies the production and coordination decisions in a closed-loop supply chain (CLSC) with one manufacturer and two competing retailers when remanufacturing costs are disrupted. We find that the pricing and production quantity decisions have certain robust regions when facing disruptions; and the more intense of competition between retailers, the smaller the robustness regions. Moreover, the manufacturer would like to adjust the production decisions when facing large size of positive or negative disruptions, while the retailers only would like to adjust them when facing large size of negative disruptions. Finally, we find that the revenue-sharing contracts can effectively coordinate the CLSCs, whereas more profits are required by retailers under large positive disruptions.     

基于R&D溢出的集中研发联盟合作行为

研究了在联盟合作R&D中R&D溢出、R&D溢出的抑制能力以及创新能力对联盟成员的R&D投资策略的影响, 确定了联盟获得最大期望投入的最优分配方式. 研究表明: 1) R&D溢出和创新能力对联盟成员增加R&D投入有正效应; 企业抑制R&D溢出的力量对R&D投入有负效应, 但影响力很弱. 2) 对于创新能力强的联盟, 平均分配为最优分配方式; 对于创新能力弱的联盟, 市场规模低时选择按投入比例分配方式, 市场规模高时选择平均分配方式.     

基于博弈论和VMI的收益共享机制协调模型

以供应商和零售商组成的二阶段供应商管理库存（ＶＭＩ）供应链系统为研究对象,考虑随机需求下的ＶＭＩ系统中可能存在的滞销成本或缺货惩罚,建立了传统、Ｓｔａｃｋｅｌｂｅｒｇ博弈、Ｎａｓｈ协商的３种收益共享机制的协调模型,并得出Ｎａｓｈ协商能完美协调分散式ＶＭＩ供应链的结论．最后,通过数值算例对相关结论进行了验证和分析．