供应链管理讨论题(I)

摘自《供应链管理：战略、规划与运作》（Supply Chain Management: Strategy, Planning, and Operation）
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1. 例如:一位顾客在便利店买一杯苏打水，请描述供应链的不同阶段，并且说明涉及的流程。

When a customer purchases a can of soda at a convenience store, his purchase represents the end of a supply chain's delivery of an item and the beginning of information regarding his purchase flowing in the opposite direction.
The supply chain stages include customers, retailers, wholesalers/distributors, manufacturers, and component/raw material suppliers. A customer's purchase moves product towards the customer and dollars and information towards the retailer.
The retailer places an order from the wholesaler/distributor to replenish stock, thereby moving information back up the supply chain while moving product down the supply chain. As the order is filled, the retailer will move dollars back up the supply chain.
The wholesaler/distributor transmits information and dollars to the manufacturer who produces product and ships it down the supply chain to the wholesaler.
Finally (or initially, depending on your perspective) the manufacturer moves orders (information) and dollars towards suppliers in exchange for material flow into their production processes.

当一个顾客在便利店买一听苏打水，他的购买行为代表着一个商品在供应链中传递的结束，同时他顺当的购买行为代表着信息在供应链相反方向的起先。
供应链平台包括消费者、零售商、批发商/分销商、生产者和零件/原材料供应商。一个顾客的购买行为是商品向顾客的转移与信息向零售商的转移。
零售商从批发商/分销商那列出一份订单，以便补充库存。因此信息是沿着供应链逆向移动而商品是顺着供应链正向移动。当订单完成后，零售商将会把资金沿着供应链的逆向传至供应链上游。
批发商/分销商将信息与资金传递给生产者即生产产品，并将（产品）顺着供应链送至批发商手中的一方。
最终（或最初，取决于你自己的观点）生产者将订单（信息）和资金转移给供应商以换取材料来投入生产流程。

2. 考虑顾客从亚马逊订购书籍的供应链，辨别推/拉界限以及这两个流程的推动和拉动阶段。

In Amazon's original operations design the push/pull boundary existed betwixt the retailer (Amazon) and their distributor. Amazon ordered product from the distributor and the customer order arrived. Today, Amazon has six warehouses where it stocks an inventory of items it is confident that will sell. In this scenario, the push/pull boundary exists between the customer and the retailer.
Processes in the pull phase are the order fulfillment, shipping, customer returns, and customer billing.
Processes in the push phase are production, stock replenishments, shipping, and payment.

在亚马逊的原始运营设计中，推/拉边界存在于零售商（亚马逊）和他们的分销商之间。亚马逊从分销商和顾客手中获得订单后订购产品。如今亚马逊有六个仓库，在这六个仓库中存放着确定会被卖出的商品。在这种状况下，推/拉边界存在于顾客和零售商之间。
拉动阶段为订单的满意、运输、顾客的反馈与顾客的发票。
推动阶段是生产、库存的补充、运输与付款。

3. 7-11 便利店、超级市场连锁店和美国好市多（Costco）这样的折扣零售商，他们面临的隐含不确定性有什么不同？

When customers go to a convenience store chain such as 7-Eleven, they go there for the convenience of a nearby store and are not necessarily looking for the lowest price. Implied demand uncertainty would be high as customers are looking for a variety of products and convenience versus cost and demand levels are hard to predict.
A supermarket chain focuses on cost and quality, with some specialty chains adding flexibility by carrying a broader range of products that may be targeted towards customers interested in organic products or ethnic cuisine. Implied demand uncertainty for a supermarket chain tends to be low; shoppers are typically repeat customers and have a constant demand level. The supermarket supply chain must be responsive by receiving produce quickly to ensure freshness and have a high service level. Supermarket supply chains tend to be well-established and can improve strategic fit by emphasizing speed to maintain freshness, hence perceived quality.
Low price is very important to customers of discount retailers such as Costco. This customer is willing to tolerate less variety and even purchase very large package sizes as long as the price is low. Customer demand can be more predictable and supply side needs are large and fairly stable.

当顾客去类似 7-11 的连锁便利店时，他们追求的是邻近商店的便利，找寻最低价对他们来说并没有必要。顾客找寻各种各样的商品时，便利性和成本相对，需求水平很难预料，隐含的需求不确定性会很高。
超级市场连锁店关注成本和质量，一些特色的连锁店因为持有大范围的目标客户群为对邮寄产品和民族烹饪有爱好的顾客的商品而增加了对敏捷性的关注。超级市场连锁店的隐含需求不确定性偏低，因为光顾的通常是老顾客并且有一个持续的需求水平。超级市场供应链确定要通过快速接收产品进行响应以确保新鲜度并保持高服务水平。

4. 当供应链的每个环节仅仅专注于自己的利润时，在作决定时会引起哪些问题？识别一些有助于零售商和制造商共同努力去拓展战略匹配范围的行动。

High inventories, poor quality, low customer service, increased returns are just a number of problems that occur when each stage of a supply chain focuses solely on its own profits. The trucking company requires full truck loads for delivery forcing the retailer to carry more inventory than wanted or needed. The supplier offers discounts to their buyers to maximize production but forcing the buyers to purchase in larger quantities than desired. This concept was very prevalent during the 1950s and 1960s as companies sought to minimize local costs and maximize their own profits.
Today, retailers and manufacturers have the opportunity to plan promotions jointly such as Wal-Mart and P&G. They can share sales information to determine customer trends. Joint product development opportunities are being explored throughout the supply chain between retailers, manufacturers and raw material suppliers.

当供应链的每个环节仅仅专注于自己的利润时，（会造成）高库存、低质量、低客户服务、增加的退货。运输公司要进行整车运输迫使零售商持有的库存比需求多。供应商给买家供应价格折扣以使生产最大化，却导致购买者买进超过需求的大批量商品。这个观念，在公司将成本最小化并且使自己的利润最大化的 20 世纪 50 年代到 60 年代很流行。
现今，零售商和制造商有机会去共同制定促销，例如沃尔玛和宝洁。他们可以共享销售信息以确定顾客购买倾向。在供应链的零售商、制造商、原材料供应商之间实现联合产品发展的机会正在探索当中。低价对于类似好市多（Costco）的折扣零售商的顾客是特别重要的。只要价格低，这些顾客很乐意接受少品种甚至大包装的商品。因此，（对于折扣零售商）顾客的需求很容易被预料，供应需求很大且稳定。

5. 汽车制造商如何运用运输提高供应链的效率？

Transportation, a logistical driver, entails moving inventory from point to point in the supply chain.
The trade-off in transportation is between the cost of transportation and the speed at which product is transported. Slower modes of transportation reduce cost, but could be a reasonable approach if suppliers are co-located with the assembly operations. If the supply chain is designed in such a way, and assembly operations are located with proximity to markets, then the supply chain can be run cheaply without holding too much inventory in transit.

运输，物流驱动因素，在供应链中需要实现货物点到点的运输。在运输中需要权衡货物运输的速度和运输成本。速度慢的运输可以降低运输成本，但是假如组装作业与供应商在同一处会是一个特别合理的方法。假如供应链依据组装作业安排在离市场非常近的地方这种方式设计供应链，这样供应链可以不需要太多的在途存货就可以以便宜的方式运行。

6. 工业物资分销商如何运用信息增加响应性？

Information is a cross-functional driver and consists of data and analysis concerning facilities, inventory, transportation, costs, prices, and customers throughout the supply chain. Information serves as a connection among all members of the supply chain and operates within each member to facilitate internal operations. Accurate information can improve responsiveness by helping an industrial supplier better match supply and demand. Information that is gathered farther down the supply chain can be transmitted instantaneously and accurately to the supplies distributor. Instead of waiting for a human to call or fax an order, the distributor can replenish inventory to the necessary levels or provide what is needed to fill the order as it is realized.

信息是一个跨职能的驱动因素，包括与设施、库存、运输、成本、价格以及整个供应链客户相关的数据和分析。信息是供应链各成员间的连接，并在每个成员内部促进操作。精确的信息可以提高响应能力，帮助工业供应商更好地匹配供应和需求。从供应链下游收集到的信息可以即时、准确地传递给分销商。无需等待人工电话或传真订单，分销商就能实时补充库存至必要水平，或立即提供所需商品以满足订单。

7. 哪种类型的分销网络最适合日用商品？

Commodity items are available from many sources and customers expect them to be delivered quickly; if a supply chain can't be responsive, the customers will move on to the next source.
A distribution network designed for retail storage with customer pickup achieves quick response for high-demand, low-variety products.
Other commodity products can be effectively distributed using distributor storage with last-mile delivery, which is also suited for high-demand, quick-response products.

商品项目可以从很多来源获得，客户期望它们能快速交付；如果供应链无法及时响应，客户就会转向下一个来源。
零售存储加顾客自提的分销网络设计，能够对高需求、低品种的产品实现快速响应。
其他商品项目也可采用经销商存储加“最后一公里”配送的方式高效分销，同样适合高需求、快速响应的产品。

8. 为什么在线渠道在 PC 行业比在食品杂货行业更加成功？在将来，在线渠道在 PC 行业的价值可能会是怎样的？

The PC industry is selling a highly customized product that is purchased on a per-household basis, less routinely than the commodity products that make up groceries.
A company like Dell can leverage the Internet as a marketing and distribution tool to advertise new capabilities and options before bricks-and-mortar retailers can.
Dell also removes whatever intimidation (or frustration) factor might be experienced by conversing with in-store sales representatives.
Computers have a very high value-to-shipping-cost ratio, so the increased shipping costs when compared to a traditional store are negligible.
Groceries have a much lower ratio; although in-store shoppers are incurring costs to pick up their groceries, those costs are hidden in comparison to the delivery charge on an itemized bill from Peapod.
E-business will continue to be a valuable tool in the PC industry; none of the advantages currently being enjoyed by Dell and Gateway are likely to change significantly.

个人电脑行业销售的是高度定制化的产品，按户购买，且购买频次远低于构成杂货的日用品。
像戴尔这样的公司可以把互联网作为营销和分销工具，在实体零售商之前宣传新功能和配置。
戴尔还消除了顾客与店内销售代表交流时可能产生的任何紧张（或挫败）情绪。
电脑的价值与运费之比非常高，因此与传统商店相比，增加的运费几乎可以忽略不计。
杂货的价值运费比则低得多；尽管店内购物者需自行承担去店取货的成本，但这些成本被隐藏在账单中，不像 Peapod 的分项运费那样明显。
电子商务将继续是 PC 行业有价值的工具；戴尔和 Gateway 目前享有的优势都不太可能发生显著变化。

9. 运输成本的上升可能会怎样影响全球化的供应链网络？

As transportation costs rise, more companies will elect to place facilities closer to the customer in order to lower overall transportation costs.
Companies must weigh these increasing costs against the cost of additional inventory and infrastructure costs in making the strategic decision where to place facilities.
As transportation costs rise, these decisions will greatly impact overall supply chain profits.

随着运输成本的上升，更多的企业选择将设施选址在离客户更近的地方，目的是在总体上降低运输成本。
企业在做设施选址问题的决策时，必须权衡这些增加的花销以及附加仓库和基础设施的花销。
因为运输成本上升，这些决策将会在很大程度上影响整个供应链的利润。

10. 考虑一个像福特公司这样的企业，其在全球的设施超过 150 个。请列出拥有很多设施的利弊并考虑这种方式是否适合汽车行业。

Automakers often use a multi-plant strategy to create server facilities.
These server facilities provide product for the market where they are located, thereby taking advantage of tax incentives, local content requirements, tariff barriers, and high logistics costs.
This can be a good strategy if market demand exists for your product; when demand drops, the producer is left with expensive excess capacity.
If the facilities are flexible, production of popular models can continue to prepare product for export.
If facilities are inflexible or all sales are flat, then the producer must bear the cost or shed assets.

汽车制造商通常实行多工厂的战略来建立服务设施。
这些设施为它们所在位置的市场供应商品，因此可以利用税率的优惠、当地需求的优势，并且避开关税壁垒和高昂的物流成本。
如果市场对这些产品存在需求，这将是一个很好的战略；当需求下降时，生产者就剩下昂贵的过剩产能。
如果设备是柔性的，通用车型的产品可继续为出口而准备生产。
如果设备是非柔性的或所有销售都趋于平缓，那么生产商必须承担成本或剥离资产。

11. 为什么在评估供应链设计决策时考虑不确定性是特别重要的？

There is little in life that is certain, so it is important to consider the impact that uncertainty has on the supply chain. Modeling techniques discussed in this text require assumptions about future demand, price structures, paradigms, etc. It is safe to say that most assumptions that we make in using these models are false; we are permitted to apply these models because the assumptions occasionally are not false enough to make a difference.
The supply chain decisions that must be made require considerable investments that cannot be changed or rescinded in the short run without incurring losses. It is important for the decision maker to weigh all alternatives and the uncertainties attached to the events that the future holds in order to arrive at the best decision.

生活中几乎没有什么事情是确定的，因此考虑不确定性对供应链的影响尤为重要。本文探讨的建模技术需要对未来需求、价格结构、范式等做出假设。可以明确地说，我们使用这些模型时所做的假设大多是错误的；我们仍被允许使用这些模型，是因为这些假设偶尔“错得不够严重”，尚不足以产生实质性影响。
供应链决策往往需要巨额投资，在短期内无法更改或撤销而不造成损失。因此，决策者必须权衡所有备选方案及未来事件所附带的不确定性，以做出最佳决策。

12. 能够影响供应链决策价值的主要的不确定性来源是什么？

The major sources of uncertainty are fluctuations in demand and price. These may vary for a number of reasons; Porter's five forces model suggests that the presence or absence of substitute goods and services, the threat of existing competitors, of new competitors and the bargaining power of customers will affect a company's existing product. Prices may fluctuate according to supply and demand, changes in tariffs and exchange rates, and inflation.

不确定性的主要来源是需求和价格的波动。造成这些波动的原因多种多样：波特的五力模型指出，替代品与服务的存在与否、现有竞争对手的威胁、新进入者的威胁以及客户的议价能力都会影响公司现有产品的表现。价格则可能因供需变化、关税和汇率变动以及通货膨胀而波动。

13. 戴尔公司如何才能与供应商进行合作预测来改进供应链？

Collaborative forecasting requires all supply chain partners to share information regarding parameters that might affect demand, such as the timing and magnitude of promotions.
Dell could share with their components suppliers all of the promotions, e.g., holiday, back-to-school, etc., they have planned.
These suppliers could, in turn, notify their suppliers of discrete components that a spike in demand is anticipated.
These demand forecasts for end items determine the demand for components and, coupled with knowledge of fabrication times, allow all members of the supply chain to provide the right quantity at the right time to their customers.

协作预测要求所有供应链合作伙伴共享可能影响需求的参数信息，如促销活动的时间和力度。
戴尔可以将其已规划的各类促销（例如假期、返校季等）与零部件供应商共享。
这些供应商再进一步通知其上游分立元件供应商需求高峰即将到来。
对最终产品的需求预测决定了零部件的需求，再结合制造周期知识，使供应链各环节都能在正确的时间向客户提供正确的数量。

14. 假如预测人员利用上一年的销售数据而不是实际需求数据进行来年的预测，会出现什么问题？

Last year's sales data is fine as long as there were no stock-outs.
If an item is not on the shelf or is explicitly indicated as being sold out, the manager may be blissfully unaware of customer demand that existed but was not expressed.
Also, if there were special promotions last year that are not planned for the following year, the data must be adjusted to accommodate this factor.

去年的销售数据在没有缺货的前提下是可用的。
如果某个产品当时缺货或明确标示已售罄，管理人员可能并未察觉到那些存在却未被满足的需求。
此外，如果去年存在特殊促销活动而次年并未计划，那么必须对数据进行调整以反映这一变化。

15. 综合计划需要输入哪些类型的成本？

The major cost categories needed as inputs for aggregate planning are production costs and inventory costs.
Production costs include labor costs of regular and overtime, costs of subcontracting production, costs of changing capacity by hiring or laying off workforce and increasing or reducing machine capacity.
Inventory costs include the cost of having too much (storage costs per period) and too little (backorder or stockout costs).

需要输入的成本类型有生产成本和库存成本。
生产成本包括正常人工成本、加班人工成本、转包生产成本和产能变更成本；其中产能变更成本具体包括雇用或解雇工人的成本，以及增加或削减机器产能的成本。
库存成本包括库存过多（每周期存储成本）和库存过少（延期交货或缺货成本）。

16. 在选择综合产品单位时，需要考虑的一些关键因素有哪些？

While planning is done at the aggregate level, it is important that the aggregate unit be identified in a way that when the final production schedule is built, the results of the aggregate plan reflect what can be accomplished in practice.
Given that the bottleneck is likely to be the most constraining area in any manufacturing facility, it is important to focus on the bottleneck when selecting the aggregate unit and identifying capacity as well as production times.
It is also important to account for activities such as setups and maintenance that use up capacity but do not result in any production.

尽管规划是在总体层面进行，重要的是综合单位的定义方式必须确保在最终生产排程制定时，综合计划的结果能够真实反映实际可完成的产量。
鉴于瓶颈工序往往是任何生产设施中最受限制的区域，在选择综合单位、确定产能以及生产时间时，必须聚焦于瓶颈。
同样需要考虑的还包括诸如换模和维护等活动，它们占用产能却不产生任何实际产出。

17. 探讨为什么转包商通常能够以低于企业自制的成本为企业供应产品和服务。

The subcontractor can offer services more cheaply for a number of reasons.
In many cases, the subcontractor is a specialist in the area and is more flexible, hence cheaper.
If a subcontractor is performing similar work for a number of clients, they can take advantage of the zero-sum nature of business competition.
By aggregating orders from a number of clients, the subcontractor is able to satisfy peaks in demand from some of their clients because other standard clients will be experiencing valleys in demand.
If subcontracting occurs because a firm is at capacity, the subcontractor (that is not overcapacity) can handle the production more cheaply simply because it is expensive to operate a system at excess capacity.

分包商可以供应更便宜的服务，原因有以下几点：
在很多情况下，分包商在该领域是专家且更具灵活性，因此成本更低。
如果分包商同时为多个客户执行类似工作，可以利用业务竞争的零和特性。
通过整合多个客户的订单，分包商能够满足某部分客户的高峰需求，因为其他常规客户正处于需求低谷。
若外包是因为企业自身产能饱和，分包商（未超产能）能以更低成本完成生产，因为在产能过剩状态下运营系统代价高昂。

18. 探讨如何为供应链中的企业建立协作机制。

Collaboration mechanisms in a supply chain should begin with the initial partnering process as the supply chain is being established.
All parties in the chain must be aligned and dedicated to the success of the entire chain.
Trust and open communication are of primary importance; there should be a myriad of formal and informal communication channels open among all parties.
If constancy of purpose is ever in question, each firm might devote some resources towards equitable “chain incentives” such that behaviors that benefit the entire supply chain are recognized and rewarded.
The incentives, communication, and trust should be established at all levels of every chain member.
Company leadership should provide for highly visible evidence of these activities on their level and among cross-business supply chain teams.

供应链合作机制应从供应链建立之初的伙伴选择阶段就开始。
链上各方必须保持一致，并致力于整个供应链的成功。
信任与开放式沟通至关重要；应在所有参与方之间建立丰富且正式/非正式的沟通渠道。
若对目标的持续性出现质疑，各企业可投入资源设立公平的“链级激励机制”，使有利于整条供应链的行为得到认可与奖励。
激励、沟通与信任须渗透到每个成员的各个层级。
公司领导层应在自身及跨业务的供应链团队层面，为这些活动提供高度可见的证据与支持。

19. 什么是牛鞭效应？它与供应链失调有何关系？

The bullwhip effect refers to the fluctuation in orders along the length of the supply chain as orders move from retailers to wholesalers to manufacturers to suppliers.
The bullwhip effect relates directly to the lack of coordination (demand information flows) within the supply chain.
Each supply chain member has a different idea of what demand is, and the demand estimates are grossly distorted and exaggerated as the supply chain partner is distanced from the customer.

牛鞭效应是指订单依次沿供应链长度逐级放大波动——从零售商到批发商，再到制造商，最后到供应商。
牛鞭效应直接源于供应链内部协调不足（需求信息流不畅）。
每个供应链成员对需求的理解各不相同，随着成员离终端客户越来越远，需求估计被严重扭曲并放大。

20. 如何在供应链内构建战略伙伴关系和信任？

Cooperation and trust within the supply chain help improve performance for the following reasons:
When stages trust each other, they are more likely to take the other party's objectives into consideration when making decisions, thereby facilitating win-win situations.
Action-oriented managerial levers to achieve coordination become easier to implement and the supply chain becomes more agile.
An increase in supply chain productivity results, either by elimination of duplicated effort or by allocating effort to the appropriate stage.
Detailed sales and production information is shared; this allows the supply chain to coordinate production and distribution decisions.

供应链中的合作与信任有助于提升绩效，原因如下：
各节点彼此信任时，在决策过程中更容易把对方目标纳入考量，从而实现双赢。
以行动为导向的管理杠杆更易落地，供应链整体变得更加敏捷。
通过消除重复劳动或将任务分配给最适合的节点，供应链整体效率显著提高。
共享详细的销售与生产信息，使供应链能够协同制定生产与配送决策。

21. 一家超市正在确定向宝洁公司补充订购的订货批量。决策时应考虑哪些成本？

The main cost categories for the supermarket's inventory policy are material costs, ordering costs, and holding costs.
Material cost is the money paid to Procter and Gamble for the goods themselves.
Ordering costs, also called procurement costs, are incurred by requesting the goods from the supplier and are fixed in the sense that they do not vary with the size of the order. Examples of such fixed costs are the labor required to place the order, handle the resultant paperwork, and the transportation fee to ship the order.
The holding cost is the cost to carry one unit in inventory for a specified period of time, usually one year. This cost is variable and includes the cost of capital and all of the costs associated with physically storing inventory—shrinkage, spoilage or obsolescence, insurance, the cost of capital, the cost of the warehouse space, etc.

超市的库存策略的主要成本类别是材料成本、订购成本及持有成本。
材料成本是指支付给宝洁公司的货物本身的价值。
订购成本（也称采购成本）在向供应商提出订货时产生，属于固定成本，不随订单大小而变化；典型例子包括下单所需人工、处理相关文书工作的费用以及订单运输费。
持有成本是指在特定期间（通常一年）内存放一个单位库存的成本，是可变成本，包括资金成本及所有与实物库存相关的费用——损耗、变质或报废、保险、资金成本、仓储空间费用等。

22. 什么情况下供应链中的数量折扣是合理的？

Quantity discounts are justified in a supply chain as long as they are the fruits of a coordinated supply chain and maximize total supply chain profits.
For commodity products for which price is set by the market, manufacturers with large fixed costs per lot can use lot size-based quantity discounts to maximize total supply chain profits.

只要数量折扣是供应链协调的结果，并能实现整个供应链利润最大化，它就是合理的。
对于市场价格已定的商品，如果制造商每批次存在较高的固定成本，可基于批量大小的数量折扣来提升整体供应链利润。

23. 安全库存在供应链中起着什么样的作用？

Safety inventory is inventory carried to satisfy demand that exceeds the amount forecasted for a given period.
As such, it tends to have a negative impact on supply chain cost but a positive impact on supply chain responsiveness.
Safety inventory is carried because product demand and lead time are uncertain and a product shortage may result if actual demand during lead time exceeds the forecast amount.

安全库存是为了满足在给定时期内超出预测需求而持有的库存。
因此，它往往对供应链成本产生负面影响，但对供应链响应能力具有积极作用。
之所以设置安全库存，是因为产品需求和交货提前期存在不确定性；如果在提前期内实际需求超过预测量，就可能发生缺货。

24. 供应不确定性对安全库存会产生哪些影响？

The required safety inventory increases with an increase in the standard deviation of periodic demand.
The standard deviation of periodic demand is a function of the variance in the lead time and the variance in the demand.
Anything that causes supply to be more deterministic will minimize the need for safety inventory.

所需安全库存会随着周期性需求标准差的增加而增加。
周期性需求的标准差取决于提前期和需求两者的波动程度。
任何能使供应变得更加确定的因素，都会减少对安全库存的需求。

25. 一家公司运用更完备的市场信息提高了预测的准确性。这将给供应链库存和盈利带来怎样的影响？为什么？

Improved forecast accuracy should result in a closer match between supply and demand, resulting in improved profitability.
An improved match will result in lower levels of unplanned carryover inventory and shortages at the end of planning periods.
The improved match will lower the expected costs of having too much or too little inventory.

提高预测准确性的结果是使供应与需求实现更紧密的匹配，从而提升利润率。
更高的匹配度将在计划期末降低无计划的库存积压和缺货水平。
同时，也会显著降低库存过多或过少的预期成本。

26. 在什么情况下，对所有产品的差异进行延迟不能增加利润？量身定制式延迟如何应用于这些情况？

Postponement is valuable in a supply chain when a firm sells a large variety of products with highly unpredictable demand of about the same size that is not positively correlated.
Postponement is not as valuable if a large fraction of the demand comes from a few products.
In such a setting, tailored postponement is most effective, whereby base loads are not postponed but the variation is postponed.

当企业销售种类繁多且需求高度不确定、规模相近且互不相关的产品时，延迟策略在供应链中极具价值。
如果大部分需求集中于少数几款产品，则全面延迟并不能显著增加利润。
在这种情况下，量身定制式延迟最为有效：基础销量部分不进行延迟，仅对差异化需求部分实施延迟。

27. 为什么在对基础设施运用定价的过程中考虑拥堵因素特别重要？

Infrastructure often requires government ownership and is not something that can be increased in capacity in the short term.
If congestion is not factored into the price structure for infrastructure, then demand for the resources will exceed capacity and major delays will occur.
Pricing may be used to force users to internalize the marginal impact of their choices, thus alleviating some of the demand during peak periods.

基础设施通常需要政府所有，且其容量在短期内难以扩充。
如果在基础设施的定价结构中不考虑拥堵因素，资源需求将超出容量，导致严重延误。
通过定价可以强制用户将其选择的外部边际成本内部化，从而缓解高峰期的部分需求。

28. 在沃尔玛设计的网络中，各个地区都建有配送中心，并由它们负责周边大型零售超市的产品供应。请说明为什么该公司利用上述网络能在频繁补货的同时降低运输成本？

A distribution center (DC) that supports several large retail stores can reduce supply chain costs in four ways:
Inbound shipments to the DC achieve economies of scale because each supplier sends a large shipment;
The outbound transportation costs for a DC can be low because it serves retail locations nearby;
Very large inbound shipments that match retail demand can be cross-docked at the DC, which saves both storage and
material-handling costs.
A DC can also replenish retail inventories more frequently; the DC breaks bulk from manufacturers on one side of the warehouse and sends it to retail locations on the outbound side.
Since retail demands are aggregated at the DC level, the amount of inventory actually stored at the DC is very low, and as Little’s Law indicates, the time between replenishments is low also.

一个支持多家大型门店的区域配送中心（DC）可在四方面降低供应链成本：
1）供应商集中大批量送货到 DC，实现进货规模经济；
2）DC 服务半径内的门店距其较近，故出库运输成本低；
3）大批量进货与门店需求匹配后可在 DC 进行越库操作，从而节省仓储与
4）物料搬运成本。
DC 还能更频繁地为门店补货：在 DC 的一侧接收来自制造商的大宗货物，在另一侧拆零后直接发向各门店。
由于门店需求在 DC 层面被聚合，实际滞留在 DC 的库存非常少，根据利特尔定律，补货间隔时间也相应缩短。

29. 虽然很多零售商外包它们的运输，但什么因素促使沃尔玛拥有自己的车队？

Wal-Mart is able to run its own fleet of trucks because it can ship TL (truckload) throughout its supply chain.
Wal-Mart's shipment sizes are large and the company achieves aggregation across the many retail stores it owns.
If Wal-Mart elected to go with a carrier, they might be able to match Wal-Mart's costs, but Wal-Mart would cede control to the carrier.

沃尔玛能够自营车队，是因为其整个供应链都可采用整车（TL）运输。
沃尔玛的货运量巨大，并且可以在其众多门店之间实现货量整合。
若选择外包承运商，虽运费可能相近，但沃尔玛会丧失对运输环节的控制权。

30. 为什么电子类消费品工业的组装由第三方担当，而汽车工业的组装几乎从未外包？

In the consumer electronics industry, the third parties aggregate the demand across multiple firms when performing assemblies, thereby gaining production economies of scale that no single firm in this industry can.
The auto industry, on the other hand, maintains volume levels for its models that each individual manufacturer can reap the benefits of their own assembly.

在电子消费品行业，第三方通过同时为多家企业提供组装服务，把需求集中起来，从而获得任何单一企业都无法实现的规模经济。
而汽车行业各车型的产量规模足够大，使每家整车厂都能自行享受组装环节带来的规模效益，因此几乎不外包组装。这也是沃尔玛自营物流的部分原因。