1、企業庫存管理外文翻譯文獻企業庫存管理外文翻譯文獻（文檔含英文原文和中文翻譯）譯文 :供應鏈下的多級存貨管理從歷史上看，多級供應鏈、倉庫、分銷商、零售商等，已經通過大量的庫存緩沖被獨立管理。競爭壓力的增加和市場的全球化迫使企業發展能夠快速滿足客戶需要的供應鏈。為了保持競爭力，降低庫存，這些企業必須交互使用多級庫存管理，同時降低運營成本，改善客戶服務。因各種不同的原因，存貨以不同形式存在在供應鏈中。在整個供應鏈中，存貨管理失衡，經常會引起“牛鞭效應”，即需求逆流而上，逐級變異放大的一個階段。這種效應引起企業過多的存貨積壓，使收入減少，運輸效率降低，擾亂了庫存計劃和產品生產計劃，同時降低了企業的服務

2、水平。許多學者已經對這些問題進行了研究，并且強調了對有效地滿足客戶需求的供應鏈各階段之間進行整合的必要性。除了整合問題，為了確定一個有效地供應鏈庫存政策，還必須處理不確定性問題。除了對供應和需求的不確定性，與生產和銷售過程相關的信息延遲也是供應鏈的一個特點。多級供應鏈中的庫存管理是一項重要的內容，因為有許多方面兩者都必須相互配合，協調合作。它們還必須對它們的庫存進行協調安排。有許多因素使成功的庫存管理變得復雜，例如。需求的不確定、交貨時間、投產日期、產品價格、成本等，尤其是在不確定性的需求和交貨時間下，管理者不能夠將多級供應鏈中的存貨管理得最優。大多數制造企業被組織起來形成了一個制造和分銷為一

3、體的網絡，這個網絡包括了原材料的采購、加工和產品的銷售。當一個產品經過多個階段才到達最終用戶時，多級或者多層次生產/分銷網絡這些代名詞也和前面所述的這樣的網絡意思相同。因各種不用的原因，存貨以不用的形式存在在整個供應鏈中。在任何一個制造過程中，它們可能作為原材料、 在制品或者產成品存在。它們存在于配送倉庫，存在于運輸途中，或者存在于管道里，它們存在于這些設備的每個鏈接處。制造商從供應商處采購原材料，將它們加工成產品并銷售給分銷商，然后由分銷商銷售給零售商或者用戶。當一個產品經過多個階段才到達最終用戶，它就形成了一個多級庫存系統。某一庫存節點的級庫存等于這個庫存節點上的所有庫存加上轉移或者正在轉

4、移的任何一個后續節點的庫存，減去后續節點的缺貨。在商界有關多級庫存系統的分析已經有著悠久的歷史。在許多領域，多級庫存管理系統被廣泛運用于向客戶分銷產品。鑒于這些系統的重要性， 許多研究人員通過各種各樣的條件和假設開始研究他們的運行特點。自從哈里斯提出經濟訂貨批量模型以來，研究人員和實際工作者更加積極地關注在不同操作參數和模型假設條件下系統的分析和模型設計。在過去的十年里，對于多級庫存管理模型的研究已經獲得了重要成就，主要是因為通過利用現代信息技術，使各個過程和分銷階段的供應鏈的整體控制逐漸變成可能。克拉克和斯卡夫最早研究兩階段存貨模型。他們證實了庫存系統的基礎存貨政策的最優性，并提出了一種用于

5、計算最佳訂貨批量的政策。貝斯勒和凡諾特進一步發展了兩階段模型，使其包含一般塊莖結構。上面提到的車間倉庫問題通過埃本和施拉格分析一個缺貨的中央倉庫模型解決了。他們在相等的訂貨點分配假設條件下，對訂購批量做出了更近似的表述。一些作者也已經考慮到了在各種形式下的這個問題。由于多階段問題的復雜和棘手，哈德利和懷廷建議對庫存系統采用單層次、單階級模型。夏布魯克把一個訂購政策看做是一個倉儲和零售商的兩級模型，他假設零售商的缺貨是完全積壓的，而且，夏布魯克還建立了矩陣（可收回項目控制的多級技術）模型，它明確了在有預算約束的一個低級階段中使庫存水平最小化，這個模型是管理服務部分庫存的第一個多級模型，此后，很多

6、研究者提出了一大套模型，他們一般都是在多級框架下尋求最佳批量和安全庫存。除了分析性模型，仿真模型也被開發了出來用于研究多級庫存問題中復雜的相互作用問題。到目前為止，相關的一些文獻主要關注于對需求的預測，以及對多階段供應鏈庫存政策的發展。需求隨機的多階段系統的存貨控制政策已經具有了一個廣泛的研究領域。近年來有許多論文都包含了斯爾福和派克的觀點。用于定期評估標準的統一采購的優點是可以通過規定不同階段的訂購水平獲得連續不斷的評估標準，這是就所有庫存而言，而不是單指設備。勞以及其他人，迪克斯和戴科克，唐格和里，密特拉和查特基，哈里加，陳，阿克斯特和章，諾齊克和特納基斯特以及賽歐和鄭都在他們的研究中利用

7、了數學模型技術去管理供應鏈中的多級存貨。迪克斯和戴科克的研究考慮到了不同的多級存貨系統，比如配送系統或者生產系統，并且假設訂單在一個固定的時間內到達。哈里加提出了由若干個裝配或者整理和儲存設備串聯在一起組成的單個周期生產系統的隨機模型。阿克斯特，諾齊克和特納基斯特在他們的文章中都提到了兩階段庫存系統。 阿克斯特和特納基斯特認為零售商都面臨不變的無偏好的泊松需要。麥徹和查特基研究了博特和格拉夫模型，并在他們關于實行快速配送商品的觀點的論文“對隨機需求下的多級存貨問題策略不間斷回顧”中進行了進一步的闡述。這個模型的提出和改進能夠擴展多個階段和兩階段配送系統的內容。在勞爾的模型中，假設訂貨時間忽略不

8、計，需求率和生產率是確定的，而且保持固定不變的情況下，缺貨是不允許的。賽歐和鄭運用分析模型分析兩個重要因素，這兩個因素能夠幫助半導體制造商根據經驗推測訂單數量變化的最高程度：一個是供應商的訂貨時間， 另一個是預測的需求更新情況。他們認為那兒的零售商面臨的外部需求與兩個連續的時間段相聯系，并且零售商利用最新的需求信息來更新它們未來的需求預測。此外，他們還認為供應商的供貨時間是變動的，而且受零售商的訂貨量的影響。頓和里在他們的論文中再次闡述了克拉克和斯卡夫的連續多級存貨系統并得出了三個關鍵的結論。第一， 他們提出了最佳多級存貨水平的最小近似值以及克拉克和斯卡夫關于基本模型的整個系統成本的最大值。第

9、二，他們利用馬丁格爾預測理論模型說明了克拉克和斯卡夫的最優存貨政策結構保留了在與時間線關聯下的按需處理。第三，他們把近似值拓展到了與時間相關聯的需求的過程和研究，特別是對于一個回歸需求模型，訂貨時間的影響和一系列存貨系統性能的相關性。通過對有關利用數學模型技術研究供應鏈下的多級存貨管理的文獻的回顧，總括起來，可以說，這些文章都考慮到了具有不確定的或者確定的需求的兩級，三級或者若干級系統。他們認為訂貨時間是固定的，為零，是一個常量，確定的或者是可以忽略的。他們獲得了準確的或者是相似的結論。德克爾等人分析了數量分段規律對存貨成本的影響。數量分段規律是指傳遞來自供應商的大訂單, 以及來自最近的零售商

10、的小訂單, 也就是所謂的進行分段數量判定訂單是小型的還是大型。在由一個供應商和多個零售商組成的系統中, 假設所有零售商的客戶都存在需求。然而 ,德克爾等人指出傳遞來自供應商的那些大型的訂單會導致零售商們考慮降低自身的存貨成本。德克爾等人的研究成果還涉及到了供應商的存貨成本。 在莫訶比和波斯納的研究中包含了存在補充訂單和銷售損失的不斷審查的存貨系統的成本分析。在范德等人的文章中考慮到了當同時存在需求和訂貨時間不確定情況下的多級存貨，周期審查，訂制點這些政策。飯田這篇文章的主要目的是表明近期政策對于多級庫存問題是可接受的。 他假設在各階段的訂貨時間是固定的。陳和宋的目標是縮小系統中的長期平均成本。

11、在陳的系統中，各地應用一種定期回顧或者訂貨點庫存政策。他們表明各地的庫存位置是穩定的，并且這種穩定的分銷是均勻且獨立于其他的。在明納等人的研究中，他調查了在一個由中心倉庫和一些當地庫存點組成的分銷網絡中，生產不確定性對庫存投資的影響。將和莫納罕論述了一個兩梯隊雙通道庫存模型，在這個模型中庫存是由生產商倉庫（上游）和零售店（下游）共同負責的，而產品使用兩種供應渠道：傳統的零售店和網絡直銷。約翰森的系統被假設由基本庫存策略控制，其中比較了獨立的和隨機不獨立的訂貨期。總之， 這些文章都基于一般隨機需求來考慮兩梯隊或者梯隊庫存系統，但有一篇例外，它考慮了馬爾可夫需求調節。通常他們假設固定的訂貨點，但是

12、其中有兩個認為那是隨機的。而他們得出了一樣或者相近的解決方法。在這些多級庫存管理文獻中用到了很多其他研究方法，比如啟發法、變化度量法、隱約集法、模型預測控制法、情景分析法、數據分析法和匯編語言，這些方法很少用而且只有少數作者會用到。陳和李提出了一個多產品、多階段、多時期計劃模型來解決帶有市場需求和產品價格不確定性的多級存貨供應網絡中的多目標。其中不確定的市場需求通過一系列各種可能性建成的離散方案模型解釋，而模糊設置用于解釋買賣者基于產品價格的不相容偏好。原文 :Multi-echelon inventory management in supply chainsHistorically, th

13、e echelons of the supply chain, warehouse, distributors, retailers, etc., have been managed independently, buffered by large inventories. Increasing competitive pressures and market globalization are forcing firms to develop supply chains that can quickly respond to customer needs. To remain competi

14、tive and decrease inventory, these firms must use multi-echelon inventory management interactively, while reducing operating costs and improving customer service.Inventories exist throughout the SC in various forms for various reasons. The lack of a coordinated inventory management throughout the SC

15、 often causes the bullwhip effect, namely an amplification of demand variability moving towards the upstream stages. This causes excessive inventory investments, lost revenues, misguided capacity plans, ineffective transportation, missed production schedules, and poor customer service.Many scholars

16、have studied these problems, as well as emphasized the need of integration among SC stages, to make the chain effectively and efficiently satisfy customer requests (e.g. reference). Beside the integration issue, uncertainty has to be dealt with in order to define an effective SC inventory policy. In

17、 addition to the uncertainty on supply (e.g. lead times) and demand, information delays associated with the manufacturing and distribution processes characterize SCs.Inventory management in multi-echelon SCs is an important issue, because there are many elements that have to coordinate with each oth

18、er. They must also arrange their inventories to coordinate. There are many factors that complicate successful inventory management, e.g. uncertain demands, lead times, production times, product prices, costs, etc., especially the uncertainty in demand and lead times where the inventory cannot be man

19、aged between echelons optimally.Most manufacturing enterprises are organized into networks of manufacturing and distribution sites that procure raw material, process them into finished goods, and distribute the finish goods to customers. The terms mul-tei chelon or multilevel production/distribnuett

20、iowno rks are alsosynonymous with such networks (or SC), when an item moves through more than one step before reaching the final customer. Inventories exist throughout the SC in various forms for various reasons. At any manufacturing point, they may exist as raw materials, work in progress, or finis

21、hed goods. They exist at the distribution warehouses, and they exist in-transit, or in the pipenli neeach pa th, loinking these facilities.Manufacturers procure raw material from suppliers and process them into finished goods, sell the finished goods to distributors, and then to retail and/or custom

22、ers. When an item moves through more than one stage before reaching the final customer,i t forms a -mecuhltei lon inventory system. The echelon stock of a stock point equals all stock at this stock point, plus in-transit to or on-hand at any of its downstream stock points, minus the backorders at it

23、s downstream stock points.The analysis of multi-echelon inventory systems that pervades the business world has a long history. Multi-echelon inventory systems are widely employed to distribute products to customers over extensive geographical areas. Given the importance of these systems, many resear

24、chers have studied their operating characteristics under a variety of conditions and assumptions. Since the development of the economic order quantity (EOQ) formula by Harris (1913), researchers and practitioners have been actively concerned with the analysis and modeling of inventory systems under

25、different operating parameters and modeling assumptions .Research on multi-echelon inventory models has gained importance over the last decade mainly because integrated control of SCs consisting of several processing and distribution stages has become feasible through modern information technology.

26、Clark and Scarf were the first to study the two-echelon inventory model. They proved the optimality of a base-stock policy for the pure-serial inventory system and developed an efficient decomposing method to compute the optimal base-stock ordering policy. Bessler and Veinott extended the Clark and

27、Scarf model to include general arbores cent structures. The depot-warehouse problem described above was addressed by Eppen and Schrage who analyzed a model with astockless central depot. They derived a closed-form expression for the order-up-to-level under the equal fractile allocation assumption. S

28、everal authors have also considered this problem in various forms. Owing to the complexity and intractability of the multi-echelon problem Hadley and Whitin recommend the adoption of single-location, single-echelon models for the inventory systems.Sherbrooke considered an ordering policy of a two-ec

29、helon model for warehouse and retailer. It is assumed that stock outs at the retailers are completely backlogged. Also, Sherbrooke constructed the METRIC (multi-echelon technique for coverable item control) model, which identifies the stock levels that minimize the expected number of backorders at t

30、he lower-echelon subject to a bud get constraint. This model is the first multi-echelon inventory model for managing the inventory of service parts. Thereafter, a large set of models which generally seek to identify optimal lot sizes and safety stocks in a multi-echelon framework, were produced by m

31、any researchers. In addition to analytical models, simulation models have also been developed to capture the complex interaction of the multi-echelon inventory problems.So far literature has devoted major attention to the forecasting of lumpy demand, and to the development of stock policies for mult

32、i-echelon SCs Inventory control policy for multi-echelon system with stochastic demand has been a widely researched area. More recent papers have been covered by Silver and Pyke. The advantage of centralized planning, available in periodic review policies, can be obtained in continuous review polici

33、es, by defining the reorder levels of different stages, in terms of echelon stock rather than installation stock.Rau et al. , Diks and de Kok , Dong and Lee ,Mitra and Chatterjee , Hariga , Chen ,Axsater and Zhang , Nozick and Turnquist ,and So and Zheng use a mathematic modeling technique in their

34、studies to manage multi-echelon inventory in SCs. Diks and de Kok ss tudy considers a divergent multi-echelon inventory system, such as a distribution system or a production system, and assumes that the order arrives after a fixed lead time. Hariga, presents a stochastic model for a single-period pr

35、oduction system composed of several assembly/processing and storage facilities in series. Chen, Axsater and Zhang, and Nozick and Turnquist consider a two-stage inventory system in their papers. Axsater and Zhang and Nozickand Turnquist assume that the retailers face stationary and independent Poiss

36、on demand. Mitra and Chatterjee examine De Bodt and Graves model (198which they developed in their paper Continuous-review policies for a multi-echelon inventory problem with stochastic deman d , for fas-tmoving items from the implementation point of view. The proposed modification of the model can

37、be extended to multi-stage serial and two -echelon assembly systems. In Rau et al. s model, shortage is not allowed, lead time is assumed to be negligible, and demand rate and production rate is deterministic andconstant. So and Zheng used an analytical model to analyze two important factors that ca

38、n contribute to the high degree of order-quantity variability experienced by semiconductor manufacturers: supplier lesa d time and forecast demand updating. They assume that the external demands faced by there tailor are correlated between two successive time periods and that the retailer uses the l

39、atest demand information to update its future demand forecasts. Furthermore, they assume that the supplier s delivery lead timeare variable and are affected by the retailer o rdesr quantities. Dong and Lee s pap erervisits the serial multi-echelon inventory system of Clark andScarf and develops thre

40、e key results. First, they provide a simple lower-bound approximation to the optimal echelon inventory levels and an upper bound to the total system cost for the basic model of Clark and Scarf. Second, they show that the structure of the optimal stocking policy of Clark and Scarf holds under time-co

41、rrelated demand processing using a Martingale model of forecast evolution. Third, they extend the approximation to the time-correlated demand process and study, in particular for an autoregressive demand model, the impact of lead times, and autocorrelation on the performance of the serial inventory

42、system.After reviewing the literature about multi-echelon inventory management in SCs using mathematic modeling technique, it can be said that, in summary, these papers consider two, three, or N-echelon systems with stochastic or deterministic demand. They assume lead times to be fixed, zero, consta

43、nt, deterministic, or negligible. They gain exact or approximate solutions.Dekker et al. analyses the effect of the break-quantity rule on the inventory costs. The break-quantity rule is to deliver large orders from the warehouse, and small orders from the nearest retailer, where a so-called break q

44、uantity determines whether an order is small or large. In most l-warehouse N-retailers distribution systems, it is assumed that all customer demand takes place at the retailers. However, it was shown by Dekker et al. that delivering large orders from the warehouse can lead to a considerable reductio

45、n in the retailer ins ventory costs. In Dekker et al. the results of Dekker et al. were extended by also including the inventory costs at the warehouse. The study by Mohebbi and Posner s contains a cost ana liyns is the context of a continuous-review inventory system with replenishment orders and lo

46、st sales. The policy considered in the paper by Vander Heijden et al. is an echelon stock, periodic review, order-up-to policy, under both stochastic demand and lead times.The main purpose of Iida s paper is thoast hnoewar-myopic policies are acceptable for a multi-echelon inventory problem. It is a

47、ssumed that lead times at each echelon are constant. Chen and Songs objective is to minimize the long-run average costs in the system. In the system by Chen et al., each location employs a periodic-review, or lot-size reorder point inventory policy. They show that each location invse ntory positions are stationary and the stationary distribution is uniform and independent of any other. In the study by Minner et al., the impact of manufacturing flexibility