Quantity-based shipment consolidation and stock replenishment policy with lead time in vendor-managed inventory system

In order to let the supplier make more reasonable supply decisions,an integrated continuous replenishment policy for the vendor-managed inventory system is presented,which considers the quantity-based shipment consolidation and stock replenishment with lead time.Then the system cost is analyzed and a mathematical model is built.Since the model is rather complex,the bounds of the optimal policy are first attained,then the problem is solved by a heuristic algorithm.Through experiments the relationship between the order lead time and the corresponding integrated policy is discussed,and the influence on the system cost is also analyzed.The results reveal that the lead time's influence on the system is more serious with the increase of the order lead time,the integrated policy with the order lead time is more reasonable and the optimal policy can minimize the total system cost.Finally,the parameter sensitivity of the model is analyzed.

Methods of vendor managed inventory control in supply chain management

By inducing the typical inventory control problem - the bullwhip effect, this paper presents vendor managed inventory (VMI) control methods on the basis of traditional methods of inventory management methods, constructs a VMI mathematics model, and analyzes the influence of VMI on inventory cost and channel profit. Finally, a special case is studied to verify that VMI is an effective supply chain strategy that can not only increase channel profit of supplier and customer but also improve full channel coordination, thereby reducing the bullwhip effect.

Vendor managed inventory and bullwhip effect

This paper studies that the bullwhip effect of order releases and the amplifications of safety stock arise within the supply chain even when the demand model is ARIMA(0, 1, 1) and the forecast method used is a simple exponentially weighted moving average. It also examines a vendor managed inventory (VMI) program to determine how it can help alleviate such negative effects, and gives the theoretical proofs and numerical illustrations. The results show that the effects with VMI are better than the effect without VMI in demand forecasting and safety stock levels, etc.

Optimization purchase price and the profit policy undervendor managed inventory

The optimization policy of the purchase price and the profit under vendor managed inventory(VMI) is studied. For a salable product, supply chain mode of VMI is established, which is based on deterministic demand, having initial stock and having stock-out cost. With the further analysis of the mode, VMI is found to increase profits of the buyer in the short-term motivation. But VMI will reduce profits of the supplier under the matching condition. And in the short-term motivation, VMI will increase the purchase price to compensate the transfer cost of the supplier. As a result, the foundation of theory is provided to implement VMI in the supply chain, and have some definituded project significance.

A Model on Inventory and Supply Management under VMI Tactics

This paper puts emphasis on how to arrange the stock and supply to the customer rationally under the VMI tactics. Having considered the supplier＇s delivery expenses, memory expenses and loss in short supply in model, the minimum total cost goal model of supply chain has been put forward using method of storing theory to charge example test the method of solving and analyzing the conclusion to propose.

Multi-objective vendor managed inventory system with interval type-2 fuzzy demand and order quantities

Purpose-The proposed IT2FMOVMI model intends to concurrently minimize total cost and warehouse space for the single vendor-retailer,multi-item and a consolidated vendor store.Regarding demand and order quantities with the deterministic and type-1 fuzzy numbers,we have also formulated the classic/crisp MOVMI model and type-1 fuzzy MOVMI(T1FMOVMI)model.The suggested solution technique can solve both crisp MOVMIand T1FMOVMIproblems.By finding the optimal ordered quantities and backorder levels,the Paretofronts are constructed to form the solution sets for the three models.Design/methodology/approach-A multi-objective vendor managed inventory(MOVMI)is the most recognized marketing and delivery technique for the service provider and the retail in the supply chain in Industry 4.0.Due to the evolving market conditions,the characteristics of the individual product,the delivery period and the manufacturing costs,the demand rate and order quantity of the MOVMI device are highly unpredictable.In such a scenario,a MOVMI system with a deterministic demand rate and order quantity cannot be designed to estimate the highly unforeseen cost of the problem.This paper introduces a novel interval type-2 fuzzy multi-objective vendor managed inventory(IT2FMOVMI)system,which uses interval type-2 fuzzy numbers(IT2FNs)to represent demand rate and order quantities.As the model is an NP-hard,the well-known meta-heuristic algorithm named NSGA-II(Non-dominated sorted genetic algorithm-II)with EKM(Enhanced Karnink-Mendel)algorithm based solution method has been established.Findings-The experimental simulations for the five test problems that demonstrated distinct conditions are considered from the real-datasets of SAPCO company.Experimental study concludes that T1FMOVMI and crisp MOVMI schemes are outclassed by IT2FMOVMI model,offering more accurate Pareto-Fronts and efficiency measurement values.Originality/value-Using fuzzy sets theory,a significant amount of work has been already done in past decades from various points of views to model the MOVMI.However,this is the very first attempt to introduce type-2 fuzzy modelling for the problem to address the realistic implementation of the imprecise parameters.

基于VMI的随机需求库存-运输整合优化模型与算法

首先给出了一个供应商和多个零售商有共同订货补充期、需求服从泊松过程的库存-运输整合优化模型,其次给出了模型的相应算法.最后,用数值例子验证了模型与算法的有效性.

存货影响销售率的无形变质物品库存-运输整合优化模型

针对供应商采购量与存货水平临界点数量关系的两种情况,主要研究物品无形变质与存货影响销售率现象对库存补充策略和运输费用的影响,进一步探讨库存-运输整合优化问题。在物品发生无形变质并允许缺货的条件下,建立了供应商的库存-运输整合优化模型,讨论了存货影响销售率现象对库存更新周期、订货批量、平均库存与运输总成本的影响,得到了供应商的最优库存更新周期和最佳订货批量。最后,通过算例进行实证研究,为供应商在无形变质物品的库存-运输整合决策中提供了借鉴与参考。

零售商订货提前期不为零时确定需求下VMI-TPL供应链的库存策略研究

供应链环境下库存管理策略已经有了很多的研究,为了使库存策略更加完善贴近实际,本文在零售商的需求确定且订货提前期为零的VMI-TPL供应链基础上研究了零售商的订货提前期不为零的相应的情况,通过建立相关的数学模型及求解得到了最优的生产策略和库存控制策略,同时也研究了在零售商订货提前期不为零时未引入TPL情况下的相应的库存策略,最后通过具体的实例将两者进行了比较得出,在零售商订货提前期不为零的情况下引入TPL仍然比未引入TPL要节省成本,证明了结论。

A Branch and Cut Algorithm for Two-Echelon Inventory Routing Problem with End-of-Tour Replenishment Policy

This study presents a two-echelon inventory routing problem (2E-IRP) with an end-of-tour replenishment (ETR) policy whose distribution network consists of a supplier, several distribution centers (DCs) and several retailers on a multi-period planning horizon. A formulation of the problem based on vehicle indices is proposed in the form of a mixed integer linear program (MILP). The mathematical model of the problem is solved using a branch and cut (B&C) algorithm. The results of the tests are compared to the results of a branch and price (B&P) algorithm from the literature on 2E-IRP with a classical distribution policy. The results of the tests show that the B&C algorithm solves 197 out of 200 instances (98.5%). The comparison of the B&C and B&P results shows that 185 best solutions are obtained with the B&C algorithm on 197 instances (93.9%). Overall, the B&C algorithm achieves cost reductions ranging from 0.26% to 41.44% compared to the classic 2E-IRP results solved with the B&P algorithm, with an overall average reduction of 18.08%.

考虑参考价格效应的库存路径与定价问题

针对客户有价格策略型行为下的供应商库存路径与定价问题(inventory routing and pricing problem,IRPP),通过将参考价格效应嵌入产品需求价格函数中,以供应商总利润最大化为目标,构建考虑参考价格效应的IRPP优化模型,设计改进的粒子群算法进行求解。通过3组不同规模的算例验证本文模型与算法的适用性和有效性。计算结果显示,考虑参考价格效应不仅有助于降低产品定价(约9%)和提升客户感知收益,而且能够降低零售商的产品总库存(约22%)、仓储资源占用成本和库存持有成本,从而提高供应商总利润(约5%)。敏感性分析结果显示:受客户记忆参数减小和增益系数增大的共同影响,供应商总利润会明显增加;受客户记忆参数和损失系数增大的共同影响,供应商总利润会迅速下降。研究结论可为电商环境下客户有价格策略型行为下的供应商IRPP优化提供决策支撑。

供应链管理中VMI系统的研究

通过分析VMI和RMI在概念原理上的本质差异,讨论了VMI在管理思想、决策方式、预测体系、补货模式、延迟策略方面的优越性和先进性。在此基础上,详细描述了VMI工作流程中的八个关键环节,并结合实际指出实施VMI的步骤和注意事项,最后总结了VMI在实践中给供应商、零售商以及供应链整体带来的收益和竞争优势。

供应商管理库存的最优购买数量和利润

研究了供应链管理环境下新的库存策略·在传统供应链利润模型基础上,对有确定需求、初始库存和允许库存短缺的一种畅销商品,建立了供应商管理库存的供应链模型,并进一步讨论了供应商管理库存下的采购数量和利润,证明了供应商管理库存供应链的最优购买量比传统供应链的最优购买量要高·同时也证明了实施供应商管理库存会使用户的利润增加,而在优化匹配条件或长期激励下,实施供应商管理库存也会使供应商的利润增加,为双方企业合并其库存提供了理论基础·最后以一个数值算例验证了所得结论·

供应商管理库存的利润模型及其优化策略

研究了供应链管理环境下新的库存策略·对有确定需求、有初始库存和库存短缺的一种畅销商品,建立了供应商管理库存的供应链模型·通过对此模型的进一步分析,证明了在供应商管理库存短期激励下,供应商管理库存将减少整个供应链的总的库存相关成本·但是这会增加供应商的库存相关成本,所以在实施供应商管理库存的起始阶段,应该首先考虑供应商和买方库存系统之间严重不匹配的商品·结果为双方企业合并其库存提供了有力的理论基础·

基于供应链间品牌竞争的库存管理策略研究

分析两个供应链间竞争的系统,每条供应链由一个供应商和一个零售商组成,供应商通过各自零售商销售具有品牌差异的产品,不同品牌产品之间存在替代度,零售商面临不确定性需求.在此系统上,存在供应商间的竞争、零售商间的竞争,和供应链内上下游之间的竞争,三种竞争交织.每条供应链有两种管理库存的方式,即零售商管理库存和供应商管理库存.通过对比不同库存管理方式下系统成员收益,发现,把不确定性需求风险从零售商转移给供应商,并非能增加零售商收益,或减少供应商收益;同时,通过分析了不同库存管理方式对供应链系统竞争均衡状态的影响,指出,在一定条件下,供应商管理库存方式能加强供应商端的竞争,使得零售商和供应商共同受益.

基于时间的供应商管理库存整合补货模式下的牛鞭效应研究

为比较基于时间的供应商管理库存整合补货模式和传统补货模式对零售业供应链中牛鞭效应的影响,概述了供应商管理库存在零售业供应链中的应用情况,构建了两种补货模式的系统动力学模型。通过仿真,定量地比较了两种补货模式中供应商和零售商对泊松流随机需求输入的订单响应率的波动。另外,为了比较基于时间的供应商管理库存整合补货模式下补货周期对牛鞭效应的影响,通过改变参数设置模拟了不同补货周期下供应商和零售商的订单响应率波动。结果显示,与传统模式相比,基于时间的供应商管理库存整合补货对牛鞭效应有明显的改善;供应商管理库存整合补货的补货周期对牛鞭效应存在明显的影响,较长周期下的牛鞭效应相对于较短周期要严重。

VMI系统下一个物流成本控制优化模型的建立

提出了在VMI系统下一个整合库存和运输决策的分析模型,考虑一个中心仓库满足来自n个在地理位置上不同的零售商的一组随机需求。中心仓库是个越库,对补货和配送进行决策,货物库存在各个零售商处。文中同时计算了优化的补货数量和配送频率(周期),建立一个面对泊松分布需求更新的理论模型。

基于收益共享机制的VMI协调

建立了收益共享机制的不同模型来协调VMI。通过数值分析得出收益共享机制下传统的VMI协调的不合理性,Stackelberg博弈的VMI协调达不到集成VMI最优收益,但可使零售商和供应商收益得到改善;Nash协商的VMI协调既能达到集成VMI最优收益,又能大大改善零售商和供应商收益,能完美协调分散式VMI。

供应商管理库存环境下库存与发货策略研究

供应商管理库存是最先进的供应链库存管理模式,也是供应链发展的重要方向。在含有多零售商的供应商管理库存环境下,为了同时满足最小化企业运营成本和最大化顾客服务水平这两个目标,分析了原有发货策略的不足,提出了新的基于时间和数量的混合发货策略,通过理论分析和仿真实验表明,混合发货策略能较好地均衡企业运营成本和顾客服务水平,更好地支撑了企业决策。

VMI实现模式研究

在供应链管理中，库存管理模式的优化，将成为制约供应链性能的关键环节。供应商管理用户库存（Ｖｅｎｄｏｒ Ｍａｎａｇｅｄ Ｉｎｖｅｎｔｏｒｙ ＶＭＩ）模式，打破了传统的各自为政的库存管理模式，体现了供应链集成管理的思想。本文系统地研究了ＶＭＩ的实现模式，比较分析了ＶＭＩ模式的综合效益，为建立一个开放的、透明的库存管理监督模式奠定了基础。在建立的ＶＭＩ实现模式下，不仅供应商可以从企业管理信息系统中获得需要的需求计划信息，而且，企业可以进一步了解ＶＭＩ的库存量和供应商的补库计划。