“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.     

Joint Initial Stocking and Transshipment—Asymptotics and Bounds

A common problem faced by many firms in their supply chains can be abstracted as follows. Periodically, or at the beginning of some selling season, the firm needs to distribute finished goods to a set of stocking locations, which, in turn, supply customer demands. Over the selling season, if and when there is a supply‐demand mismatch somewhere, a re‐distribution or transshipment will be needed. Hence, there are two decisions involved: the one‐time stocking decision at the beginning of the season and the supply/transshipment decision throughout the season. Applying a stochastic dynamic programming formulation to a two‐location model with compound Poisson demand processes, we identify the optimal supply/transshipment policy and show that the optimal initial stocking quantities can be obtained via maximizing a concave function whereas the contribution of transshipment is of order square‐root‐of T. Hence, in the context of high‐volume, fast‐moving products, the initial stocking quantity decision is a much more important contributor to the overall profit. The bounds also lead to a heuristic policy, which exhibits excellent performance in our numerical study; and we further prove both the bounds and the heuristic policy are asymptotically optimal when T approaches infinity. Extension to multiple locations is also discussed.     

Safety Stock,Excess Capacity or Diversification: Trade‐Offs under Supply and Demand Uncertainty

Firms mitigate uncertainty in demand and supply by carrying safety stock, planning for excess capacity and diversifying supply sources. In this study, we provide a framework to jointly optimize these three levers in a periodic review infinite horizon setting, and in particular we examine how one can reduce inventory and capacity investments through proper diversification strategies. Observing that a modified base‐stock inventory policy is optimal, we find that the capacity‐diversification problem is well behaved and characterize the optimal mix of safety stock, excess capacity and extra number of supply sources. We find that higher supply uncertainty results in higher safety stock, more excess capacity, and higher diversification. But safety stock and diversification are non‐monotonic in demand uncertainty. Our results can be extended to situations in which suppliers are heterogeneous, and can be used to develop effective heuristics.     

农民专业合作社存货质押融资运作模式分析

解决融资问题是保障农民专业合作社可持续发展的重要问题之一。把农民专业合作社生产加工或闲置的存货作为质押物向银行融资是解决其融资困境的有效途径。本文在分析农民专业合作社开展存货质押融资业务的现实条件基础上,并结合其拥有存货特性和质押融资业务特征,提出了银行直接质押模式和专业担保公司担保模式、供应链核心企业担保模式及农民专业合作社联合担保三种担保模式,并进行对比分析的基础提出有政府扶持和第四方物流参与的优化模式,以期为缓解农民专业合作社融资困境提供决策借鉴。     

农村村级组织财务管理存在的问题与对策——对贵州省农村的实地调研分析

村级组织财务管理是社会主义新农村建设的重要内容,是完善农村公共产品融资机制的制度基础。对贵州省7个地州市9个县31个行政村的实地调研结果显示,贵州农村村级组织财务管理存在的主要问题是:会计基础工作薄弱,财务管理制度不规范;会计人员选聘机制不合理,人员素质亟待提高;民主监督职能弱化,审计监督乏力;村级债务较为严重等。为了切实提高农村村级组织财务管理水平,必须扎实推进"村财乡代管"制度,改革村级财务人员选任模式,健全民主理财监督制度,加强村级财务审计监督,并努力化解村级债务问题。     

一个基于数量折扣的变质商品定价和库存模型

建立了一个变质率为指数分布基于数量折扣的变质商品定价和库存模型，模型考虑资本的时间价值性，给出了模型解的算法．计算结果表明，资本的时间价值性和商品的变质特性对最优决策者有重要影响．     

Managing Production and Distribution for Supply Chains in the Processed Food Industry

We develop and evaluate a modeling approach for making periodic review production and distribution decisions for a supply chain in the processed food industry. The supply chain faces several factors, including multiple products, multiple warehouses, production constraints, high transportation costs, and limited storage at the production facility. This problem is motivated by the supply chain structure at Amy's Kitchen, one of the leading producers of natural and organic foods in the United States. We develop an enhanced myopic two‐stage approach for this problem. The first stage determines the production plan and uses a heuristic, and the second stage determines the warehouse allocation plan and uses a non‐linear optimization model. This two‐stage approach is repeated every period and incorporates look‐ahead features to improve its performance in future periods. We validate our model using actual data from one factory at Amy's Kitchen and compare the performance of our model to that of the actual operation. We find that our model significantly reduces both inventory levels and stockouts relative to those of the actual operation. In addition, we identify a lower bound on the total costs for all feasible solutions to the problem and measure the effectiveness of our model against this lower bound. We perform sensitivity analysis on some key parameters and assumptions of our modeling approach.     

RFID‐Enabled Visibility and Retail Inventory Record Inaccuracy: Experiments in the Field

Accurate inventory records are key to effective store execution, affecting forecasting, ordering, and replenishment. Prior empirical research, however, shows that retailer inventory records are inherently inaccurate. Radio Frequency Identification (RFID) enables visibility into the movement of inventories in the supply chain. Using two different field experiments, the current research investigates the effectiveness of this visibility in reducing retail store inventory record inaccuracy (IRI). Study 1 used an interrupted time‐series design and involved daily physical counts of all products in one category in 13 stores (8 treatments and 5 controls) of a major global retailer over 23 weeks. Results indicate a significant decrease in IRI of approximately 26% due to RFID‐enabled visibility. Using an untreated control group design with pre‐test and post‐test, Study 2 expands the number of categories to five and the number of stores to 62 (31 treatment and 31 control stores). Results show that the effectiveness of RFID in reducing IRI varies by category (ranging from no statistically significant improvement to 81%). Results also suggest that RFID ameliorates the effects of known determinants of IRI and provide the key insight that the technology is most effective for product categories characterized by these determinants.     

开放经济下人民币汇率制度选择分析

2 0世纪 80年代以来 ,金融全球化趋势日渐明显 ,伴随着资本流动的加快和汇率波动的频繁 ,金融危机时有发生。而历次金融危机都与汇率制度的安排和国际资本流动密切相关 ,这使得汇率制度的选择成为各国政府无法回避的理论和现实问题。中国现行的汇率制度是以市场供求为基础的、单一的、有管理的浮动汇率制 ,其实质是“有管理而无浮动”的固定汇率制 ,面对“入世”后金融业的对外开放和资本项目的逐步放开 ,目前的汇率制度将受到严峻挑战。本文从现行汇率制度的缺陷入手 ,以蒙代尔 -弗莱明模型为理论分析框架 ,着重对人民币汇率的市场化改革提供政策建议     

Optimal Planning Quantities for Product Transition

The replacement of an existing product with a new one presents many challenges. In particular, uncertainties in a new product introduction often lead to extreme cases of demand and supply mismatches. This paper addresses inventory planning decisions for product upgrades when there is no replenishment opportunity during the transition period. We allow product substitution: when a company runs out of the old product, a customer may be offered the new product as a substitute. We show that the optimal substitution decision is a time‐varying threshold policy and establish the optimal planning policy. Further, we determine the optimal delay in a new product introduction, given the initial inventory of the old product.