供應(yīng)鏈下的多級(jí)存貨管理【外文翻譯】

1、本科畢業(yè)論文（設(shè)計(jì)）外 文 翻 譯原文：Multi-echelon inventory management in supply chains Historically, the 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 firm

2、s to develop supply chains that can quickly respond to customer needs. To remain competitive and decrease inventory, these firms must use multi-echelon inventory management interactively, while reducing operating costs and improving customer service. Supply chain management (SCM is an integrative ap

3、proach for planning and control of materials and information flows with suppliers and customers, as well as between different functions within a company. This area has drawn considerable attention in recent years and is seen as a tool that provides competitive power .SCM is a set of approaches to in

4、tegrate suppliers, manufacturers, warehouses, and stores efficiently, so that merchandise is produced and distributed at right quantities, to the right locations and at the right time, in order to minimize system-wide costs while satisfying service-level requirements .So the supply chain consists of

5、 various members or stages. A supply chain is a dynamic, stochastic, and complex system that might involve hundreds of participants.Inventory usually represents from 20 to 60 per cent of the total assets of manufacturing firms. Therefore, inventory management policies prove critical in determining t

6、he profit of such firms. Inventory management is, to a greater extent, relevant when a whole supply chain (SC, namely a network of procurement, transformation, and delivering firms, is considered. Inventory management is indeed a major issue in SCM, i.e. an approach that addresses SC issues under an

7、 integrated perspective.Inventories exist throughout the SC in various forms for various reasons. The lack of a coordinated inventory management throughout the SC often causes the bullwhip effect, namely an amplification of demand variability moving towards the upstream stages. This causes excessive

8、 inventory investments, lost revenues, misguided capacity plans, ineffective transportation, missed production schedules, and poor customer service.Many scholars have studied these problems, as well as emphasized the need of integration among SC stages, to make the chain effectively and efficiently

9、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 addition to the uncertainty on supply (e.g. lead times and demand, information delays associated with the manufacturing and distribution p

10、rocesses characterize SCs.Inventory management in multi-echelon SCs is an important issue, because there are many elements that have to coordinate with each other. They must also arrange their inventories to coordinate. There are many factors that complicate successful inventory management, e.g. unc

11、ertain demands, lead times, production times, product prices, costs, etc., especially the uncertainty in demand and lead times where the inventory cannot be managed between echelons optimally.Most manufacturing enterprises are organized into networks of manufacturing and distribution sites that proc

12、ure raw material, process them into finished goods, anddistribute the finish goods to customers. The terms multi-echelon or multilevelproduction/distribution networks are also synonymous with such networks (or SC, when an item moves through more than one step before reaching the final customer. Inve

13、ntories exist throughout the SC in various forms for various reasons. At any manufacturing point, they may exist as raw materials, work in progress, or finished goods. They exist at the distribution warehouses, and they exist in-transit, or in the pipeline, on each path linking these facilities.Manu

14、facturers procure raw material from suppliers and process them into finished goods, sell the finished goods to distributors, and then to retail and/or customers. When an item moves through more than one stage before reaching thefinal customer, it forms a multi-echelon inventory system. The echelon s

15、tock 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 its downstream stock points.The analysis of multi-echelon inventory systems that pervades the business world has a long history. Multi-echelon inve

16、ntory systems are widely employed to distribute products to customers over extensive geographical areas. Given the importance of these systems, many researchers have studied their operating characteristics under a variety of conditions and assumptions. Since the development of the economic order qua

17、ntity (EOQ formula by Harris (1913, researchers and practitioners have been actively concerned with the analysis and modeling of inventory systems under different operating parameters and modeling assumptions .Research on multi-echelon inventory models has gained importance over the last decade main

18、ly because integrated control of SCs consisting of several processing and distribution stages has become feasible through modern information technology. 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 inve

19、ntory system and developed an efficient decomposing method to compute the optimal base-stock ordering policy. Bessler and Veinott extended the Clark and Scarf model to include general arbores cent structures. The depot-warehouse problem described above was addressed by Eppen and Schrage who analyzed

20、 a model with a stockless central depot. They derived a closed-form expression for the order-up-to-level under the equal fractile allocation assumption. Several authors have also considered this problem in various forms. Owing to the complexity and intractability of the multi-echelon problem Hadley

21、and Whitin recommend the adoption of single-location, single-echelon models for the inventory systems.Sherbrooke considered an ordering policy of a two-echelon model for warehouse and retailer. It is assumed that stock outs at the retailers are completely backlogged. Also, Sherbrooke constructed the

22、 METRIC (multi-echelon technique for coverable item control model, which identifies the stock levels that minimize the expected number of backorders at the lower-echelon subject to a bud get constraint. This modelis the first multi-echelon inventory model for managing the inventory of service parts.

23、 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 many researchers. In addition to analytical models, simulation models have also been developed to capture the complex interaction of the multi-echelo

24、n inventory problems.So far literature has devoted major attention to the forecasting of lumpy demand, and to the development of stock policies for multi-echelon SCs Inventory control policy for multi-echelon system with stochastic demand has been a widely researched area. More recent papers have be

25、en covered by Silver and Pyke. The advantage of centralized planning, available in periodic review policies, can be obtained in continuous review policies, 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

26、 and Lee ,Mitra and Chatterjee , Hariga , Chen ,Axsater and Zhang , Nozick and Turnquist ,and So and Zheng use a mathematic modeling technique in their studies to manage multi-echelon inventory in SCs. Diks and de Koks study considers a divergent multi-echelon inventory system, such as a distributio

27、n 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 production system composed of several assembly/processing and storage facilities in series. Chen, Axsater and Zhang, and Nozick and Turnquist consider

28、a two-stage inventory system in their papers. Axsater and Zhang and Nozickand Turnquist assume that the retailers face stationary and independent Poisson demand. Mitra and Chatterjee examine De Bodt and Graves model (1985, which they developed in their paper Continuous-review policies for a multi-ec

29、helon inventory problem with stochastic demand, for fast-moving items from the implementation point of view. The proposed modification of the model can 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 negli

30、gible, and demand rate and production rate is deterministic and constant. So and Zheng used an analytical model to analyze two important factors that can contribute to the high degree of order-quantity variability experienced bysemiconductor manufacturers: suppliers lead time and forecast demand upd

31、ating. They assume that the external demands faced by there tailor are correlated between two successive time periods and that the retailer uses the latest demand information to update its future demand forecasts. Furthermore, they assume that the suppliers delivery lead times are variable and are a

32、ffected by the retailers order quantities. Dong and Lees paper revisits the serial multi-echelon inventory system of Clark and Scarf and develops three key results. First, they provide a simple lower-bound approximation to the optimal echelon inventory levels and an upper bound to the total system c

33、ost 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-correlated demand processing using a Martingale model of forecast evolution. Third, they extend the approximation to the time-correlated demand process

34、and study, in particular for an autoregressive demand model, the impact of lead times, and autocorrelation on the performance of the serial inventory system.After reviewing the literature about multi-echelon inventory management in SCs using mathematic modeling technique, it can be said that, in sum

35、mary, these papers consider two, three, or N-echelon systems with stochastic or deterministic demand. They assume lead times to be fixed, zero, constant, deterministic, or negligible. They gain exact or approximate solutions.Dekker et al. analyses the effect of the break-quantity rule on the invento

36、ry 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 quantity determines whether an order is small or large. In most l-warehouseN-retailers distribution systems, it is assumed that all customer demand tak

37、es place at the retailers. However, it was shown by Dekker et al. that delivering large orders from the warehouse can lead to a considerable reduction in the retailers inventory costs. In Dekker et al. the results of Dekker et al. were extended by also including the inventory costs at the warehouse.

38、 The study by Mohebbi and Posners contains a cost analysis in the context of a continuous-review inventory system with replenishment orders and lost sales. The policy considered in the paper by Vander Heijden et al. is an echelon stock, periodicreview, order-up-to policy, under both stochastic deman

39、d and lead times.The main purpose of Iidas paper is to show that near-myopic policies are acceptable for a multi-echelon inventory problem. It is assumed 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 C

40、hen et al., each location employs a periodic-review, or lot-size reorder point inventory policy. They show that each locations inventory 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 flexib

41、ility on inventory investments in a distribution network consisting of a central depot and a number of local stock points is investigated. Chiang and Monahan present a two-echelon dual-channel inventory model in which stocks are kept in both a manufacturer warehouse (upper echelon and a retail store

42、 (lower echelon, and the product is available in two supply channels: a traditional retail store and an internet-enabled direct channel. Johansens system is assumed to be controlled by a base-stock policy. The independent and stochastically dependent lead times are compared.To sum up, these papers c

43、onsider two- or N-echelon inventory systems, with generally stochastic demand, except for one study that considers Markov-modulated demand. They generally assume constant lead time, but two of them accept it to be stochastic. They gain exact or approximate solutions.In multi-echelon inventory manage

44、ment there are some other research techniques used in literature, such as heuristics, vary-METRIC method, fuzzy sets, model predictive control, scenario analysis, statistical analysis, and GAs. These methods are used rarely and only by a few authors.A multi-product, multi-stage, and multi-period sch

45、eduling model is proposed by Chen and Lee to deal with multiple incommensurable goals for a multi-echelon SC network with uncertain market demands and product prices. The uncertain market demands are modeled as a number of discrete scenarios with known probabilities, and the fuzzy sets are used for

46、describing the sellers and buyers incompatible preference on product prices.In the current paper, a detailed literature review, conducted from an operational research point of view, is presented, addressing multi-echelon inventory management in supply chains from 1996 to 2005.Here, the behavior of t

47、he papers, against demand and lead time uncertainty, is emphasized.The summary of literature review is given as: the most used research technique is simulation. Also, analytic, mathematic, and stochastic modeling techniques are commonly used in literature. Recently, heuristics as fuzzy logic and GAs

48、 have gradually started to be used.Source: A Taskin Gumus* and A Fuat Guneri Turkey, 2007. “Multi-echelon inventory management in supply chains with uncertain demand and lead times: literature review from an operational research perspective”. IMechE Vol. 221 Part B: J. Engineering Manufacture. June,

49、 pp.1553-1570.譯文：供應(yīng)鏈下的多級(jí)存貨管理從歷史上看，多級(jí)供應(yīng)鏈、倉(cāng)庫(kù)、分銷(xiāo)商、零售商等，已經(jīng)通過(guò)大量的庫(kù)存緩沖被獨(dú)立管理。競(jìng)爭(zhēng)壓力的增加和市場(chǎng)的全球化迫使企業(yè)發(fā)展能夠快速滿(mǎn)足客戶(hù)需要的供應(yīng)鏈。為了保持競(jìng)爭(zhēng)力，降低庫(kù)存，這些企業(yè)必須交互使用多級(jí)庫(kù)存管理，同時(shí)降低運(yùn)營(yíng)成本，改善客戶(hù)服務(wù)。供應(yīng)鏈管理是一種集成的管理思想和方法，它執(zhí)行供應(yīng)鏈中從供應(yīng)商到最終用戶(hù)以及公司內(nèi)部不同部門(mén)之間的物流的計(jì)劃和控制等職能。最近幾年，供應(yīng)鏈管理這個(gè)領(lǐng)域已經(jīng)引起了廣泛關(guān)注，并且它被視作能夠幫助企業(yè)獲得競(jìng)爭(zhēng)優(yōu)勢(shì)的一種工具。供應(yīng)鏈管理是為了在滿(mǎn)足服務(wù)水平的同時(shí)使系統(tǒng)成本達(dá)到最小，從而把供應(yīng)商、制造商、倉(cāng)庫(kù)和

50、商店的業(yè)務(wù)效率都整合起來(lái)，使商品以正確的品質(zhì)、在正確的地點(diǎn)、在正確的時(shí)間進(jìn)行生產(chǎn)和銷(xiāo)售的一套方法?？梢?jiàn)，供應(yīng)鏈由各種各樣的成員或者階段組成。供應(yīng)鏈?zhǔn)且粋€(gè)動(dòng)態(tài)的、隨機(jī)的和復(fù)雜的系統(tǒng)，因此，需要許許多多的人來(lái)參與。在制造企業(yè)中，存貨通常占企業(yè)總資產(chǎn)的20%到60%。因此，對(duì)于那些追求利潤(rùn)的企業(yè)，存貨管理政策是關(guān)鍵。當(dāng)考慮到整個(gè)供應(yīng)鏈 ，也就是一個(gè)由采購(gòu)、轉(zhuǎn)化和運(yùn)輸公司組成的網(wǎng)絡(luò)時(shí)，存貨管理在很大程度上就與這整個(gè)供應(yīng)鏈有關(guān)。在供應(yīng)鏈管理中，存貨管理的確是一種主要方法，它能從整體上解決供應(yīng)鏈問(wèn)題。因各種不同的原因，存貨以不同形式存在在供應(yīng)鏈中。在整個(gè)供應(yīng)鏈中，存貨管理失衡，經(jīng)常會(huì)引起“牛鞭效應(yīng)”，即需

51、求逆流而上，逐級(jí)變異放大的一個(gè)階段。這種效應(yīng)引起企業(yè)過(guò)多的存貨積壓，使收入減少，運(yùn)輸效率降低，擾亂了庫(kù)存計(jì)劃和產(chǎn)品生產(chǎn)計(jì)劃，同時(shí)降低了企業(yè)的服務(wù)水平。許多學(xué)者已經(jīng)對(duì)這些問(wèn)題進(jìn)行了研究，并且強(qiáng)調(diào)了對(duì)有效地滿(mǎn)足客戶(hù)需求的供應(yīng)鏈各階段之間進(jìn)行整合的必要性。除了整合問(wèn)題，為了確定一個(gè)有效地供應(yīng)鏈庫(kù)存政策，還必須處理不確定性問(wèn)題。除了對(duì)供應(yīng)（比如交貨時(shí)間）和需求的不確定性，與生產(chǎn)和銷(xiāo)售過(guò)程相關(guān)的信息延遲也是供應(yīng)鏈的一個(gè)特點(diǎn)。多級(jí)供應(yīng)鏈中的庫(kù)存管理是一項(xiàng)重要的內(nèi)容，因?yàn)橛性S多方面兩者都必須相互配合，協(xié)調(diào)合作。它們還必須對(duì)它們的庫(kù)存進(jìn)行協(xié)調(diào)安排。有許多因素使成功的庫(kù)存管理變得復(fù)雜，例如。需求的不確定、交貨時(shí)

52、間、投產(chǎn)日期、產(chǎn)品價(jià)格、成本等，尤其是在不確定性的需求和交貨時(shí)間下，管理者不能夠?qū)⒍嗉?jí)供應(yīng)鏈中的存貨管理得最優(yōu)。大多數(shù)制造企業(yè)被組織起來(lái)形成了一個(gè)制造和分銷(xiāo)為一體的網(wǎng)絡(luò)，這個(gè)網(wǎng)絡(luò)包括了原材料的采購(gòu)、加工和產(chǎn)品的銷(xiāo)售。當(dāng)一個(gè)產(chǎn)品經(jīng)過(guò)多個(gè)階段才到達(dá)最終用戶(hù)時(shí)，多級(jí)或者多層次生產(chǎn)/分銷(xiāo)網(wǎng)絡(luò)這些代名詞也和前面所述的這樣的網(wǎng)絡(luò)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(gè)供應(yīng)鏈中。在任何一個(gè)制造過(guò)程中，它們可能作為原材料、在制品或者產(chǎn)成品存在。它們存在于配送倉(cāng)庫(kù)，存在于運(yùn)輸途中，或者存在于管道里，它們存在于這些設(shè)備的每個(gè)鏈接處。制造商從供應(yīng)商處采購(gòu)原材料，將它們加工成產(chǎn)品并銷(xiāo)售給分銷(xiāo)商，然后由分

53、銷(xiāo)商銷(xiāo)售給零售商或者用戶(hù)。當(dāng)一個(gè)產(chǎn)品經(jīng)過(guò)多個(gè)階段才到達(dá)最終用戶(hù)，它就形成了一個(gè)多級(jí)庫(kù)存系統(tǒng)。某一庫(kù)存節(jié)點(diǎn)的級(jí)庫(kù)存等于這個(gè)庫(kù)存節(jié)點(diǎn)上的所有庫(kù)存加上轉(zhuǎn)移或者正在轉(zhuǎn)移的任何一個(gè)后續(xù)節(jié)點(diǎn)的庫(kù)存，減去后續(xù)節(jié)點(diǎn)的缺貨。在商界有關(guān)多級(jí)庫(kù)存系統(tǒng)的分析已經(jīng)有著悠久的歷史。在許多領(lǐng)域，多級(jí)庫(kù)存管理系統(tǒng)被廣泛運(yùn)用于向客戶(hù)分銷(xiāo)產(chǎn)品。鑒于這些系統(tǒng)的重要性，許多研究人員通過(guò)各種各樣的條件和假設(shè)開(kāi)始研究他們的運(yùn)行特點(diǎn)。自從哈里斯提出經(jīng)濟(jì)訂貨批量模型以來(lái)，研究人員和實(shí)際工作者更加積極地關(guān)注在不同操作參數(shù)和模型假設(shè)條件下系統(tǒng)的分析和模型設(shè)計(jì)。在過(guò)去的十年里，對(duì)于多級(jí)庫(kù)存管理模型的研究已經(jīng)獲得了重要成就，主要是因?yàn)橥ㄟ^(guò)利用現(xiàn)代信

54、息技術(shù)，使各個(gè)過(guò)程和分銷(xiāo)階段的供應(yīng)鏈的整體控制逐漸變成可能?？死撕退箍ǚ蜃钤缪芯?jī)呻A段存貨模型。他們證實(shí)了庫(kù)存系統(tǒng)的基礎(chǔ)存貨政策的最優(yōu)性，并提出了一種用于計(jì)算最佳訂貨批量的政策。貝斯勒和凡諾特進(jìn)一步發(fā)展了兩階段模型，使其包含一般塊莖結(jié)構(gòu)。上面提到的車(chē)間倉(cāng)庫(kù)問(wèn)題通過(guò)埃本和施拉格分析一個(gè)缺貨的中央倉(cāng)庫(kù)模型解決了。他們?cè)谙嗟鹊挠嗀淈c(diǎn)分配假設(shè)條件下，對(duì)訂購(gòu)批量做出了更近似的表述。一些作者也已經(jīng)考慮到了在各種形式下的這個(gè)問(wèn)題。由于多階段問(wèn)題的復(fù)雜和棘手，哈德利和懷廷建議對(duì)庫(kù)存系統(tǒng)采用單層次、單階級(jí)模型。夏布魯克把一個(gè)訂購(gòu)政策看做是一個(gè)倉(cāng)儲(chǔ)和零售商的兩級(jí)模型，他假設(shè)零售商的缺貨是完全積壓的，而且，夏布魯

55、克還建立了矩陣（可收回項(xiàng)目控制的多級(jí)技術(shù)）模型，它明確了在有預(yù)算約束的一個(gè)低級(jí)階段中使庫(kù)存水平最小化，這個(gè)模型是管理服務(wù)部分庫(kù)存的第一個(gè)多級(jí)模型，此后，很多研究者提出了一大套模型，他們一般都是在多級(jí)框架下尋求最佳批量和安全庫(kù)存。除了分析性模型，仿真模型也被開(kāi)發(fā)了出來(lái)用于研究多級(jí)庫(kù)存問(wèn)題中復(fù)雜的相互作用問(wèn)題。到目前為止，相關(guān)的一些文獻(xiàn)主要關(guān)注于對(duì)需求的預(yù)測(cè)，以及對(duì)多階段供應(yīng)鏈庫(kù)存政策的發(fā)展。需求隨機(jī)的多階段系統(tǒng)的存貨控制政策已經(jīng)具有了一個(gè)廣泛的研究領(lǐng)域。近年來(lái)有許多論文都包含了斯?fàn)柛：团煽说挠^點(diǎn)。用于定期評(píng)估標(biāo)準(zhǔn)的統(tǒng)一采購(gòu)的優(yōu)點(diǎn)是可以通過(guò)規(guī)定不同階段的訂購(gòu)水平獲得連續(xù)不斷的評(píng)估標(biāo)準(zhǔn)，這是就所有庫(kù)存而言，而不是單指設(shè)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了數(shù)學(xué)模型技術(shù)去管理供應(yīng)鏈中的多級(jí)存貨。迪克斯和戴科克的研究考慮到了不同的多級(jí)存貨系統(tǒng)，比如配送系統(tǒng)或者生產(chǎn)系統(tǒng)，并且假設(shè)訂單在一個(gè)固定的時(shí)間內(nèi)到達(dá)。哈里加提出了由若干個(gè)裝配或者整理和儲(chǔ)存設(shè)備串聯(lián)在一起組成的單個(gè)周期生產(chǎn)系統(tǒng)的隨機(jī)模型。阿克斯特，諾齊克和特納基斯特在他們的文