制造商的供应商管理——柔性线路板案例研究【外文翻译】.doc

1、 外文翻译 原文 Supplier management for manufacturer a case study of flexible PCB Material Source: Springer Link Author: Victor B. Korong I.C. Wang Abstract The purpose of this study is to provide a guideline for manufacturer with multiple products on suppliers selection. The proposed approach has been con

2、structed based on the total cost, given that each supplier possesses different unit prices, purchasing lead time, and variability. A case study of a Taiwanese company manufacturing flexible printed circuit boards (PCBs) is used to illustrate the proposed model, from which the following can be conclu

3、ded: supplier selection does affect expected raw material cost, expected relevant inventory cost, setup cost, expected capacity cost, transportation cost, and eventually the total cost. Instead of unit price, total cost should be the criterion for supplier selection. In addition, there exists a rela

4、tionship of trade-off between expected capacity cost and transportation cost. fKeywords: Purchasing Inventory Capacity Lead time Cost 1 Introduction Time has become an increasingly important factor to manufacturers in obtaining their competitive advantage. Shorter lead time means improved customer s

5、ervice, less inventory, and higher efficiency 1. Take for an example of make-to-order manufacturing, 54% of the delivery time is spent waiting, which shows to a great improvement potential 2. The cost of purchased materials constitutes about 50% of the total sales for a typical American manufacturin

6、g firm 3, which explains the importance of the match between supplier and material procurement. Sere et al. 4 stated that the procurement of raw materials and components used in the manufacturing process is a critical managerial task. The buyers problem is to decide how much to order per period in o

7、rder to maximize its expected profit. Although a variety of factors may be crucial while selecting a supplier, the purchase cost is usually the most dominant one 5. An efficient delivery schedule to please customers has always been a challenge. To achieve such, a manufacturer generally has to purcha

8、se material earlier than needed. In addition, reserve excess capacity and transportation with higher cost are even necessary to fulfill the order commitment. The purpose of this study is to construct an optimal expected total cost model, which can offer a guideline to assess and select appropriate s

9、uppliers to support multiple products manufacturing. This model reflects not only the unit price but also the purchasing lead time and variability. A case study of flexible printed circuit boards (PCBs) is included as well to illustrate the effectiveness of the proposed model. 2 Literature review Sh

10、in et al. 6 constructed the supply-chain measurement model in terms of supplier and buyer performance. Supplier performance includes cost, quality, delivery reliability, lead time, and on-time delivery. On the other hand, buyer performance includes product performance, product features, product reli

11、ability, product conformance, and product durability. The major criteria to select a supplier include quality, delivery, cost, and flexibility 7. In the principles stated by Sparkman et al. 8, total cost has been included for supplier management. Sari and Bemoan 9 divided the total cost into four gr

12、oups, which are (1) the raw material purchasing price (includes transportation cost), (2) fixed and variable cost associated with plant operation, (3) the variable costs of handling and inventory of the product, and (4) transportation costs for the finished product. According to Ghodsypour and OBrie

13、n 10, annual raw material cost is the annual quantity purchased times the unit price. In addition, Lawrence 11 introduced a total relevant cost model for the supply chain, which includes the cost of processing orders, holding average inventory, holding safety stock, and the stock outs. From this mod

14、el, the safety stock and the cost of stock out were interfered with by the lead time and variability. As Hur and Paik 12 stated in their queuing model, an operating system often needs to be set up before the server starts his service, and service in turn has costs and needs a policy to control the s

15、ervice. Among many control policies used, the N- policy is the most common one, where the server does not start its service until there are N customers in the queue. Okamura et al. 13 also adopted the N-policy to evaluate the performance of M/M/1 single server queues. In addition, Koulamas 14 illust

16、rated the annual setup cost as being equal to the setup cost times the number of ordering cycles in a year. Gilbert and Ballou 15 stated that the advantage for the suppliers to possess lower stock cost and less excess capacity is from advanced customer commitment. Furthermore,Tyworth and Zeng 16 ill

17、ustrated that the expected total annual logistics cost is the sum of transportation, holding, ordering, and shortage cost in which transportation cost is further related to freight rate, annual demand, and weight. 3 The optimal expected total cost model The purpose of this model is to explore the ef

18、fect on the total cost of the manufacturer when purchasing material from different suppliers, who offer different unit prices, purchasing lead time, and variability. The optimal expected total cost model proposed is expected to offer a guideline for supplier management. The following assumptions wer

19、e made: (1) the quality of the material from all suppliers is acceptable and consistent, (2) the quality of products manufactured is acceptable and consistent, (3) total cost is the only factor for supplier selection and (4) in order to assure on-time delivery, the manufacturer has to utilize the mo

20、st efficient transportation approach when choosing the supplier with the longest purchasing lead time. The expected delivery time (EDT) of a manufacturer is comprised of three major elements shown in Fig. 1: (1) Expected lead time of purchasing (ELTP): The expected time frame from placing an order t

21、o the receipt of raw material. (2) Expected lead time of manufacturing (ELTM): The expected time frame from the receipt of raw material to finished products ready to be shipped. (3) Lead time of transportation (LTT): The time frame from shipment to the receipt of customers. The top of Fig. 1 represe

22、nts the EDT of a manufacturer who purchases from a supplier with the longest ELTP, and the bottom represents a manufacturer who purchases from any other supplier with shorter ELTP. In order to objectively compare the different manufacturers total costs from potential suppliers, the manufacturers EDT

23、s are assumed to be identical regardless of the ELTP for each supplier. The supplier with the longest ELTP always dictates how long the EDT must be, where all other suppliers will definitely have shorter ELTPs. As a result, when the manufacturer purchases from any other supplier with a shorter ELTP,

24、 the ELTM and/or the LTT tend to possess more time. 3 1 Structure of the expected total cost model Purchasing from different suppliers leads to the following changes of expected total cost (ETC): （ 1） Expected raw material cost (ERMC): The ERMC will reduce when the unit price drops. （ 2） Expected re

25、levant inventory cost (ERIC): The EOQ will increase when the unit price drops, which also leads to lower ordering cost and stock out cost. On the other hand, the safety stock and stock out costs will decrease as well when the ELTP and/or the variability is reduced. （ 3） Setup cost (SC): The EOQ incr

26、eases when the unit price drops, which will result in lower set up. The SC is, therefore, lowered. （ 4） Expected capacity cost (ECC): The reduction of ELTP leads to the extension of ELTM, which can naturally reduce ECC as well. （ 5） Transportation cost (TC): ELTP reduction leads to the extension of

27、available LTT. Some lower cost with time-consuming transportation approaches become feasible. The expected total cost (ETC) can, therefore, be obtained as follows： ETC = ERMC + ERIC + SC + ECC + TC The above matches the total cost model presented by Sabri and Beamon 9. The equipment cost (in ECC) an

28、d SC are fixed; however, the direct labor cost (in ECC) is variable. 4 Case study A flexible PCB manufacturing company located in Taiwan, which is a supplier to Notebook PC, Printer, hard disk drive, and camera manufacturers, has been selected as an example of the proposed approach. Similar to other

29、 electronic companies, the subject company has to face short delivery lead time, rush orders, and low yield, where excess inventory and capacity are normally needed to fulfill the demand of customers. The subject company, therefore, must have an effective supplier selection policy for the responsive

30、 market. Optimal expected total cost model solution: The production flow of the flexible PCB includes design, front processes, patterning, lamination, surface treatment, and back processes. During the patterning process, etching has been a bottleneck, due to its low yield. The single-layer and multi

31、layer products must utilize different production facilities, which both fit the M/M/1 queuing model. Relative operation information of the subject company is listed in Table 1. In addition, Table 2 lists three of their products that deliver to the same destination. Cover lay is the main raw material

32、, which is common to all three products and has to be purchased in a unit of a roll. Company A and B are the current suppliers of cover lay, with transaction de- tails listed in Table 3. Supplier A offers a lower price, however, with longer ELTP and higher variability when compared with supplier B.

33、Supplier selection policy: The cost differences between suppliers A and B can be obtained. Although supplier A offers lower unit price, which, it has longer ELTP with higher variability. The combined characteristics result in higher TC compared with supplier B. In terms of cost; this case study demo

34、nstrates the fact that, rather than focusing only on the unit price, total cost is the ultimate criterion to select a supplier. 5 Conclusions This study demonstrates how a multiple products manufacturer can select its supplier based on the optimal total cost. The following findings are shown in this

35、 study: (1) The unit price, expected purchasing lead time, and variability affect expected raw material cost, expected relevant inventory cost, setup cost, expected capacity cost. (2) There exists a trade-off relationship between expected capacity cost and transportation cost. (3) Instead of only be

36、ing concerned about unit price, the expected total cost should be the criterion of supplier selection. The proposed model and conclusions in this study offer guideline for supplier selection with optimal cost analysis, where a constructive suggestion for manufacturers is included as well. 译文 制造商的供应商

37、管理 柔性线路板案例研究 资料来源： Springer Link 作者： Victor B. Korong I.C. Wang 摘要 这个研究的目的是为制造商的多样性产品在供应商选择中提供指导方针。这个被提议的方法已经在总成本的基础上被构建，假如每个供应商控制着不同的单价，采购提前期，和多变性。一家台湾公司的柔性线路板制造的案例曾经被用来举例说明这个方法，从这个案例中我们可以得到以下的结论：供应商选择在原材料成本方面达到了预期的影响效果； 预计的存 货成本；生产准备成本，预计生产能力成本；运输成本以及最后的总成本。选择供应商的标准不是单价而应该是总成本。另外，在交易中还存在着预期生产能力和运输

38、成本的关系。 关键词：采购；库存；生产力；提前期；成本 1 介绍 时间在制造商获得竞争优势变得越来越重要。缩短提前期意味着客户服务质量的提高，库存的减少和高效 1。举一个制造业的例子，运输中 54%的时间用在了等待上，这个有很大的潜在改进空间 2。 一家美国制造公司的采购材料成本构成有 50%在总销售量，这就说明了供应商和材料采购之间合作的重要性。Sere et al. 4 说制造过程中原材料和零配件的采购是一个决定性的管理工作。买方的问题在于决定每个阶段多少的订购量才能使自身获得最大的预期利润。尽管，在供应商的选择上有很多重要的因素，但是采购成本往往的最明显的一个因素 5。 用一个有效的交货

39、时间表来让客户满意往往是一个挑战。为了达到目的，制造商总要在需要之前预先采购材料。另外，为满足订单保证储备超额生产能力和高额的运输费用都是必须的。 这个研究的目的就是要构建一个最理想的预期的总成本模型来提供一个评价和选择供应商的指导方针支持 制造商。这个模型反映的不仅仅是单 价而是采购提前期和可变性。柔性线路板的制造案例用来说明这个被提议的模型。 2 文献综述 Shin et al 根据供应商和买方绩效构建了供应链测量模型。供应商绩效包括成本，质量，运输可靠性，提前期和准时交货。另一方面买方绩效包括产品绩效产品特征，产品可靠性，产品一致性和产品使用年限。主要的选择供应商的标准包括质量、运输、成

40、本和灵活性 7。 Sparkman et al 8规定总成本 应该包括爱在供应商管理中。 Sari 和 Bemoan 将总成本分为四个部分：分别是（ 1）原材料采购价格（包括运输成本）；（ 2）工 厂运营中的固定成本和可变成本；（ 3）装卸搬运和库存中的可变成本；（ 4）制成品的运输成本。 根据 Ghodsypour 和 OBrien每年的原料成本等于每年的采购量乘以单价。此外， Lawrence11为供应链介绍了一个相关成本模型，包括订单处理的成本、保持平均库存的成本、保持安全库存和卸货的成本。这个模型中，安全库存和卸货成本都受提前期和可变性的影响。正如 Hur 和 Paik 所说，在他们的

41、排队模型中， 在服务者提供服务之前需要建立一个操作系统，和策略来控制产生的成本。在那些使用过的控制策略中， N 是最常用的一个， 等到有 N 个客户在他们的队列中时服务者才开始他们的服务。 Okamura 13 也采用了这个 N策略来评估 M/M/1单个服务队列的绩效。 Koulamas 14 举例说明年度生产成本应该等于生产成本乘以每年的订购次数。 Gilbert 和 Ballou15说供应商拥有低库存成本和超额生产能力的优势来自提前的对顾客的承诺。此外， Tyworth 和 Zeng 16说预期的物流总成本是运输费、保持、 订购和短缺成本的总和，其中运输成本和海运运率，年需求量和重量有关。

42、 3 预期的最理想的总成本模型 这个模型的目的是为了探测当从不同的提供不同单价、不同提前期和可变性的供应商手中采购原料 时对制造商总成本的影响。预期的理想的总成本模型是被期望可以为供应商管理提供指导方针的。提出以下一些假设：（ 1）所以供应商的材料都是一致的并且是可以被接受的；（ 2）产品的制造也是一直并可以被接受的；（ 3）选择供应商总成本是唯一考虑标准；（ 4）为保证及时交货，当选择供应商有最长的采购提前期时制造商必须使用效率最高的运输途径。 制造 商的预期交货时间 (EDT)由三个主要元素组成，如表 1： （ 1） 预期 采购提前期 (ELTP)：预期时间范围从下订单到收到原材料。 （

43、2） 预期 制造 提前期 (ELTM)：预期时间范围从收到原材料到完成产品准备装船。 （ 3） 运输提前期 (LTT)：时间范围从装船到顾客收到货。 表一的顶部 显示出用最长预期采购提前期的制造商的预期交货时间，底部表现出其他用较短预期采购提前期的制造商的预期交货时间。为了客观的比较不同制造商从潜在供应商得到的总成本，制造商的预期交货时间假定完全相同不管每个供应商的预期采购提前期。有最长预期采购提前期的供应商往往指 示预期交货时间的多久，当其他所有供应商明确的指出有更短的预期采购提前期时。结果，制造商从其他较短预期采购 提前期的供应商处采购，他的预期制造提前期和运输提前期就延长了。 3.1 预

44、期总成本模型结果 从不同供应商处采购导致了一下预期总成本 (ETC)的改变： （ 1） 预期原材料成本 (ERMC)：当单价下降会节约原材料总成本。 （ 2） 预期相关库存成本 (ERIC)：经济订购批量会随着单价的下降而上升，这会使订单成本和出货成本降低。另外，当预期采购提前期和可变成本降低时，安全库存和出货成本降低。 （ 3） 生产准备成本 (SC)：当单价降低经济批量上升时，会使生产减少，因此生产准备成本降低了。 （ 4） 预计生产能力成本 (ECC)：预计采购提前期的减少导致预期制造提前期的增加，自然地使预期生产能力成本减少了。 （ 5） 运输成本 (TC)：预期采购提前期的降低导致有

45、效的运输提前期的延长。有些低成本但耗时较长的运输方式也成为了可行的方法。 因此，可得到预计总成本 (ETC)为以下这个公式： 预计总成本 (ETC)=预计原材料成本 (ERMC)+预计相关库存成本 (ERIC)+生产准备成本 (SC)+预计生产能力成本 (ECC)+运输成本 (TC) 以上所述与总成本模型相匹配的公式由 Sabri和 Beamon9所提出。设备成本 (在预计生产能力成本中 )和生产准备成本是固定的，然而，直接人工成本 (在预计生产能力成本中 )是可变的。 4 案例分析 柔性线路板制造公司位于台湾，是笔记本电脑、打印机、硬盘驱动器和照相机制造商的供应商， 已经被选为这个方法的案例

46、。与其他电子产品公司相同，这个公司必须面对短期交货提前期，紧急订单，低产量，过量的库存加压和生产能力要满足客户的需求。因此，公司必须有一个有效的供应商选择策略来响应市场。 理想的预期总成本模型解决方案：柔 性线路板的生产流程包括设计、前部加工、仿造、蚀刻、层压、表面处理和后续加工。仿造过程中，蚀刻是一个障碍，因为它的低产量。单层和多层的产品必须利用不同也使用于 M/M/1 排队模型的生产设备。 覆盖面是主要的原材料，它是三个产品共同的，并且要进行一系列采购的。 A 公司和 B 公司是覆盖面当前的供应商，与供应商 B 相比较供应商 A 提供较低的价格，但是需要较长的预期采购提前期和较高的可变性。

47、 供应商选择策略：可知供应商 A 和供应商 B 的成本是不同的。尽管供应商A 提供了较低的单价，但是其需要较长的预期采购提前期和较高的可变性。这种组合 特征导致较高的总成本，相较于供应商 B。根据成本，这个案例论证了 只关注单价是不够的，总成本才是最终选择供应商的标准。 5 结论 这个案例论证了在理想总成本模型的基础上多样性的产品制造商如何选择其供应商。一下是这个案例中结果： （ 1） 单价、预期采购提前期和可变性影响预期原材料成本，预期有关的库存成本，生产准备成本、预期生产能力成本。 （ 2） 在生产能力成本和运输成本之间存在着交易关系。 （ 3） 供应商的选择不应该仅仅考虑单价，预期总成本才是选择供应商的标准。 通过理想成本分析，案例中所提及的模型和结论为制造商在供应 商选择上提供了指导方针，同时还给出了有建设性的建议。