变库存费的变质性物品的最优订货策略

经典的 EOQ模型所解决的问题都是视库存费为常数 ,在这篇文章中 ,我们研究了库存费的二种可能的变化 :(A)库存费的变化率为存贮时间的函数 ;(B)库存费的变化率为库存量的函数 .揭示了变库存费对库存系统最优订货策略的影响     

允许缺货的时滞变质物品的库存模型

本文给出了允许缺货,一订货就交货的时滞变质物品的存贮问题.并给出了最优库存策略     

一类跳扩散需求存贮系统(s,S)库存控制策略研究

考虑的是连续检查库存,需求为一个常时间函数和-个复合Poison跳扩散随机过程的和的存贮系统最优库存控制问题.基于期望折扣成本最小建立了无穷时间区间具有固定订购成本的最优库存模型,确定可采用(s,S)策略进行库存控制,给出了最优(s,S)策略的充要条件--HJB方程Ⅰ、Ⅱ.我们采用"猜测"的方法确定了最优(s,S)策略对应的值函数形式,建立了确定库存参数的最优化模型.     

双向替代产品库存模型研究

运用最优控制理论和数理经济学方法研究了供应链管理时代下广泛存在的双向替代产品的最优库存问题,建立了利润最大化前提下的双向替代品的库存模型,证明了该问题解的存在性,并给出了求解最优订货量的方法步骤,可为实施有效的库存管理、降低企业的物流成本提供借鉴.     

一个具有可变需求率的工业存贮模型及其最优存贮策略

本文研究在一个水平周期τ上具有可变需求率的连续盘点的工业库存系统。文中建立了此库存系统的费用模型,讨论了该系统的最优存贮策略;同时,文中还给出了此模型的一个特例。     

基于混杂控制方法的生产库存策略的研究

研究了生产库存混杂动态模型的最优控制策略.首先,建立了生产库存系统的混杂动态模型,给出了其性能指标函数包含生产成本和库存成本的最优控制问题.基于参数化方法和古典的最优控制理论,给出了混杂动态最优控制问题的最优性必要条件.最后,利用该混杂最优性条件,得到了生产库存混杂动态控制问题的最优生产和库存策略,验证了结论的有效性.     

一类变质性物品在考虑信用期时的补货策略

随着人们物质生活的不断丰富,库存控制系统所处的环境变得既复杂又多变,光靠规模化的经营已经不能满足顾客的需要,经典的EOQ模型的订购批量解也与实际的最优值之间具有很大的差距.由次,本文修改了EOQ模型中的一些假设,在考虑信用期的情况下,研究了需求率为常数、物品存贮寿命为两参数维布尔分布的单一变质性物品在有限计划期内的补货策略,证明了最优补货策略的存在性及惟一性,同时给出了求解最优补货策略的算例,得到了应用更为广泛的结论.     

基于订货满足率的订单装配系统中的库存管理

在本文中,我们研究了订单装配系统的订货满足率问题.在给定库存费用上限的条件下,给出了最优的基本库存水平,并且给出了计算库存水平的方法.     

仓库容量有限条件下的随机存贮管理模型

以商场的商品销售与存贮为研究对象,建立了一类在仓库容量有限条件下的存贮管理决策模型,并给出了最优存贮策略.针对某个大型超市的三种商品的真实销售数据,我们运用该模型分析求解得出了三种商品的最优订货点L*分别为35、39和40.结合销售存贮管理中的实际情况,我们针对商场同时订购多种商品时的情况对模型进行了初步推广,并依据此推广模型得出了在同时订购三种商品时的最优订货点L*为7.2.最后我们进一步讨论了在商品销售率随存贮时间发生变化及存贮变质性商品时的存贮管理决策模型,以便满足不同商家的订货和存贮策略.     

风险厌恶条件下竞争报童问题的二层规划模型

有效应用数学规划方法研究报童类产品的库存管理,能够降低企业的成本和风险,从而提高企业的经济效益.此类问题的研究,目前主要集中在应用Nash博弈研究竞争报童问题以及零售商所持风险态度对供应链库存水平的影响.试图研究序贯决策下的竞争报童问题模型以及零售商所持风险态度对供应链库存水平的影响.由此建立了二层规划模型.算例表明序贯决策的竞争报童问题中,总订购量随风险厌恶程度的提高而降低.     

Comparing improvement strategies for inventory inaccuracy in a two-echelon supply chain

Classical inventory theory often assumes no discrepancies between recorded inventory and actual inventory. However, inventory records are usually inaccurate due to many reasons in practice. For example, inventory shrinkage refers to the difference between booked inventory that a company should have as a result of its sales, purchasing, and manufacturing processes and actual inventory that it has on hand. This paper concerns the impact of inventory shrinkage to a supply chain and investigates different strategies to deal with inventory shrinkage. We consider a single-period two-echelon supply chain consisting of a Stackelberg manufacturer and a retailer whose inventory is subject to shrinkage errors. Our analysis is based on a single-period newsvendor model and considers the following cases of order decisions: (a) the retailer ignores the inventory errors; (b) the retailer estimates the errors; (c) the retailer shares the inventory error information with the manufacturer; and (d) RFID technology is used to reduce or eliminate the errors. The first case is the base strategy and a common practice for many supply chains, the other two represent certain non-technological strategies of the retailer when dealing with inventory inaccuracy, and the last one represents a technology improvement strategy by the manufacturer to reduce or eliminate inventory shrinkage errors. We compare these improvement strategies and derive critical tag price for RFID implementation as a technological remedy for the inventory inaccuracy problem. Conditions for the profitability of RFID adoption are discussed.     

基于质押贷款下的库存管理问题的研究

库存决策不仅受需求、运输费用、储存费用的影响,而且企业本身的资金状况也会限制企业实施库存管理.以报童模型为原型,讨论了企业存在道德风险的情况下,以仓单质押方式融资的企业的库存管理决策.假设企业是风险中性的并且商品的储存费用不小于商品的处理价格.研究发现,只有质押库存比较小的企业才会用掉所有的贷款限额.并且随着贷款价值比的增加,企业有可能保留部分资金,而使用贷款增加库存.     

Credit financing in a two-warehouse environment for deteriorating items with price-sensitive demand and fully backlogged shortages

In the current global market, organizations use many promotional tools in order to increase their sales. One such tool is permissible delay in payments, i.e., the buyer does not have to pay for the goods purchased immediately rather can defer the payment for a prescribed period given by the supplier. This phenomenon motivates the retailer/buyer to order a large inventory lot so as to take full benefit of credit period. But the well decorated showroom (OW) with modern facilities has a limited storage capacity. Thus the retailer has to hire a rented warehouse to store the excess units. In this scenario, retailer usually adopts two types of dispatch policy: FIFO & LIFO, depending upon the situation, e.g., nature of items/deteriorating items, location of warehouse. Further in order to survive in the market, the retailer dynamically adjusts the prices of the goods to boost the demand and enhance the revenues.In the light of these facts, this paper develops an inventory model for deteriorating items with price-sensitive demand under permissible delay in payment in a two warehouse environment. Shortages are allowed and fully backlogged. The objective of this study is to find the optimal inventory and pricing policies so as to maximize the total average profit. Further, the different trade credit scenario has been exhibited with the help of a numerical example. A comprehensive sensitivity analysis has also been carried out to advocate the implication of FIFO and LIFO dispatch policy.     

Consignment contracting: Who should control inventory in the supply chain?

Consignment is a popular form of business arrangement where supplier retains ownership of the inventory and gets paid from the retailer based on actual units sold. The popularity of such an arrangement has come with some continued debates on who should control the supply chain inventory, the supplier or retailer. This paper aims at shedding light on these debated issues. We consider a single period supply chain model where a supplier contracts with a retailer. Market demand for the product is price-sensitive and uncertain. The supplier decides his consignment price charged to the retailer for each unit sold, and the retailer then chooses her retail price for selling the product. We study and compare two different consignment arrangements: The first allows the retailer to choose the supply chain inventory, together with her retail price, and is labeled as a Retailer Managed Consignment Inventory (RMCI) program; and the second calls for the supplier to decide the inventory, together with his consignment price, and is labeled as a Vendor Managed Consignment Inventory (VMCI) program. We show that with an RMCI program, the supply chain loses at least 26.4% of its first-best (expected) profit, while with VMCI, it loses just or no more than 26.4% of the first-best profit. Second, we demonstrate that both programs lead to an equal split of the corresponding channel profit between the supplier and the retailer. These results indicate that it is beneficial both to the supplier and to the retailer when delegating the inventory decision to the supplier rather than to the retailer in the channel.     

Dynamic pricing of limited inventories for multi-generation products

In this research, we consider a retailer selling products from two different generations, both with limited inventory over a predetermined selling horizon. Due to the spatial constraints or the popularity of a given product, the retailer may only display goods from one specific generation. If the transaction of the displayed item cannot be completed, the retailer may provide an alternative from another generation. We analyze two models - posted-pricing-first model and negotiation-first model. The former considers negotiation as being allowed on the price of the second product only and in the latter, only the price of the first product is negotiable. Our results show that the retailer can adopt both models effectively depending on the relative inventory levels of the products. In addition, the retailer is better off compared to the take-it-or-leave-it pricing when the inventory level of the negotiable product is high.     

A Production Lot-Size Model for Perishable Items Under Two Level Trade Credit Policy for a Retailer with a Powerful Position in a Supply Chain System

This paper investigates a production lot-size inventory model for perishable items under two levels of trade credit for a retailer to reflect the supply chain management situation. We assume that the retailer maintains a powerful position and can obtain full trade credit offered by supplier yet retailer just offers the partial trade credit to customers. Under these conditions, retailer can obtain the most benefits. Then, we investigate the retailer’s inventory policy as a cost minimization problem to determine the retailer’s inventory policy. A rigorous mathematical analysis is used to prove that the annual total variable cost for the retailer is convex, that is, unique and global-optimal solution exists. Mathematical theorems are developed to efficiently determine the optimal ordering policies for the retailer. The results in this paper generalize some already published results. Finally, numerical examples are given to illustrate the theorems and obtain a lot of managerial phenomena.     

A manufacturer's optimal quantity discount strategy and return policy through game-theoretic approach

This study generalised the traditional quantity discount problem with return contracts, in which a manufacturer promises to refund some fraction of the retailer's wholesale price if an item is returned, as a two-stage game. In the first stage the manufacturer and retailer determine the inventory level cooperatively. In the second stage, the manufacturer bargains with the retailer for quantity discount and return schemes to maintain channel efficiency. A menu of discount–return combinations is proposed for the manufacturer to make inventory decisions. The model developed will demonstrate that the return policy can be considered as mirror images of quantity discount strategy. That is, options with more generous return privileges are coupled with higher wholesale prices, whereas the lowest wholesale price comes with very strict limits on returns and a restocking fee for any returned goods.     

Analysis of a fuzzy economic order quantity model for deteriorating items under retailer partial trade credit financing in a supply chain

This paper investigates the economic order quantity (EOQ) — based inventory model for a retailer under two levels of trade credit to reflect the supply chain management situation in the fuzzy sense. It is assumed that the retailer maintains a powerful position and can obtain the full trade credit offered by the supplier yet the retailer just offers a partial trade credit to customers. The demand rate, holding cost, ordering cost, purchasing cost and selling price are taken as fuzzy numbers. Under these conditions, the retailer can obtain the most benefits. Study also investigates the retailer’s inventory policy for deteriorating items in a supply chain management situation as a cost minimization problem in the fuzzy sense. The annual total variable cost for the retailer in fuzzy sense is defuzzified using Graded Mean Integration Representation method. Then the present study shows that the defuzzified annual total variable cost for the retailer is convex, that is, a unique solution exists. Mathematical theorems and algorithms are developed to efficiently determine the optimal inventory policy for the retailer. Numerical examples are given to illustrate the theorems and the algorithms. Finally, the results in this paper generalize some already published results in the crisp sense.     

Stock Rationing in a Continuous Review Two-Echelon Inventory Model

In this paper we consider a 1-warehouse, N-retailer inventory system where demand occurs at all locations. We introduce an inventory model which allows us to set different service levels for retailers and direct customer demand at the warehouse. For each retailer a critical level is defined, such that a retailer replenishment order is delivered from warehouse stock if and only if the stock level exceeds this critical level. It is assumed that retailer replenishment orders, which are not satisfied from warehouse stock, are delivered directly from the outside supplier, instead of being backlogged. We present an analytical upper bound on the total cost of the system, and develop a heuristic method to optimize the policy parameters. Numerical experiments indicate that our technique provides a very close approximation of the exact cost. Also, we show that differentiating among the retailers and direct customer demand can yield significant cost reductions.     

二层信用策略下部分延期付款的库存模型

当前二层信用期相关文献考虑的都是零售商提供给其顾客相同的信用期,但现实中零售商往往会根据物品的种类不同提供给顾客不同的信用期.为研究此问题,建立了优化供货周期使零售商平均相关成本最小的库存模型,证明了最优供货周期的存在性,并给出实例加以说明.