1、 3 供应链管理导论 物流网络构造 库存管理与风险分担 信息价值 供应链整合 战略联盟 采购及外包战略 供应链管理的全球化问题 协调的产品与供应链设计 顾客价值和供应链管理 供应链管理的信息技术 供应链管理决策支持系统 4 马士华等.供应链管理.高等教育出版社，2010 大卫辛奇利维等著，季建华等译.供应链设计与管理 ：概念、战略与案例研究.中国财政经济出版社，2010 David Simchi-Levi, et al. Designing 1 Product Considering transportation costs only Customer data Original Data h
2、ad 18000 ship-to locations Aggregated Data had 800 ship-to locations Total demand was the same in both cases 83 Total Cost:$5,796,000 Total Customers: 18,000 Total Cost:$5,793,000 Total Customers: 800 Cost Difference 0.05% 84 实际中通常使用以下方法汇总数据： 将需求点汇总为150200个区域 -若依顾客服务水平或配送频率分类，则每一类将有150200个汇总点 确保每个区域
3、的总需求量大致相等（每个区域的地理面积可能 并不相等） 在区域的中心放置汇总点 将产品汇总成2050个产品组 85 Companies may have hundreds to thousands of individual items in their production line Variations in product models or style Same products are packaged in many sizes Collecting all data and analyzing them is impractical for so many product gro
4、ups 86 Place all SKUs (Stock-Keeping Units，最小存货单位) into a source-group A source group is a group of SKUs all sourced from the same place(s) Within each of the source-groups, aggregate the SKUs by similar logistics characteristics Weight Volume Holding Cost 87 0.0 10.0 20.0 30.0 40.0 50.0 60.0 70.0 0
5、.0000.0100.0200.0300.0400.0500.0600.0700.0800.0900.100 Volume (pallets per case) Weight (lbs per case) Rectangles illustrate how to cluster SKUs. 88 5 Plants 25 Potential Warehouse Locations Distance-based Service Constraints Inventory Holding Costs Fixed Warehouse Costs Product Aggregation 46 Origi
6、nal products 4 Aggregated products were created 89 Total Cost:$104,564,000 Total Products: 46 Total Cost:$104,599,000 Total Products: 4 Cost Difference : 0.03% 90 运输费率估计是构建有效配送网络设计模型的重要环节 大多数运输费率（包括卡车、铁路及其他运输方式）与 运输距离呈线性关系，而不与运量呈线性关系 运输费率估计 公司内部车队，涉及每辆卡车的年费用、年行驶里程、年运 量、有效运力 公司外部车队，分为整车运输和零担运输 91 整车运
7、输（TL: Truck Load） TL 承运人为顾客提供区域间的运输费率表，费率表中列有 任意两区域间每辆卡车每英里的运输费用 零担运输（LTL: Less Than Truck Load） LTL 运输费率有三种：等级（Class）费率、特价（ Exception）费率、特定商品（Commodity）费率 92 等级（Class） 是标准费率，几乎所有的产品或商品都有相应的标准费率。它们可根据 分类费率表（Classification Tariff）被分类，每种商品都有一个类别 （Rating or Class） -如火车运输采用 Uniform Freight Classificatio
8、n，含31种等级（从400到 13） -而卡车运输采用 National Motor Freight Classification，含23种货物等 级（从500到35） 等级越高，其运输费率就越高 A number of factors are involved in determining a products specific class. These include -Density -Ease or difficulty of handling and transporting -Liability for damage 93 特价（Exception）费率 用来提供较低费率 特定商品
9、（Commodity）费率 提供特定商品的运输费率 LTL 计费工具：基于邮政编码的LTL费率计算系统CZAR-Lite 为货主提供一个公平的计价系统，并防止任何承运人偏离市 场的行为而影响货主的选择 94 95 运输成本是运输距离的一个函数，因此我们需要一个工 具来估计距离 69：美国地区一个纬度的大约英里数 绕行系数（Circuity Factor）：都市区=1.3；美国大陆 =1.14（乘上Dab，以考虑实际的道路距离） 地理信息系统（GIS）的应用 2 2 69 babaab latlatlonlonD 22 1 2 sincoscos 2 sinsin692 ba ba ba ab
10、lonlon latlat latlat D 96 搬运成本（Handling Costs） 包括劳工及公用设施成本 与仓库年物流量成比例 固定成本（Fixed Costs） 包括所有不与仓库年物流量成比例的成本 通常固定成本与仓库大小（容量）成比例，但不是线性的 持有成本（Carrying Costs） 代表库存持有成本，与平均库存水平成比例 97 有了仓库年货物流量后，该如何估计实际需要的空 间（1000单位） 仓库年货物流量除以库存周转率可得平均库存水平 （周转率=10；AI=100） 需要的储存空间约为平均库存的两倍 将所需的储存空间乘上一大于1的系数，通常为3 即：估计容量 = 单位
11、储存空间 X 平均库存水平 X 2 X 3 98 好的位置必须满足下列条件： 地理及基础设施条件 自然资源及劳力的可得性 当地产业及税收制度 公共利益 99 定义服务水平有许多方法，例如我们可在每个顾客与提 供其服务的仓库间限定一个最大距离，这可以保证仓库 能在一合理的时间内服务顾客 但是我们较难提供给那些位于偏远地区的顾客与其它顾 客相同水平的服务。因此，常定义服务水平为某一比例 的顾客距离提供其服务的仓库不可超过某一距离 例如要求95%顾客所在的位置距离提供其服务的仓库不可超过 200英里 100 战略层次的决策（包括设计分销网络）对公司而言有长 期的影响，特别是与仓库的数量、位置、大小有
12、关的决 策，对公司的影响将长达3-5年，也就是说设计网络时要 考虑未来几年顾客需求的变化 通常会用基于情景（Scenario-Based）的方法来解决 $- $10 $20 $30 $40 $50 $60 $70 $80 $90 0246810 Number of Warehouses Cost (millions $) Total Cost Transportation Cost Fixed Cost Inventory Cost Avg. # of WH31425 Pharmaceuticals Food CompaniesChemicals - High margin product -
13、 Service not important (or easy to ship express) - Inventory expensive relative to transportation - Low margin product - Service very important - Outbound transportation expensive relative to inbound 103 确保数据及模型正确地反映网络设计问题的程序，称为 模型及数据的验证（Model and Data Validation） 通常利用模型和搜集的数据重构现有的网络结构，并将 模型的输出结果与现有
14、的数据作比较 104 这些数据与公司的会计信息相比较，通常是找出数据、有问题的 假设、建模缺陷等方面错误的最佳方法。例如在某一个案中，经 验证程序计算出来的运输成本与会计数据建议的成本相比较，一 直被低估 经仔细检查后，咨询人员下结论说是卡车的有效承载量只有可载重量的30% ，也就是说卡车以很少的承载量运送 对网络结构做局部或小的改变，看系统如何评估对成本及服务水 平的影响（灵敏度分析）。此步骤包括提出一些假设性的问题， 例如： 如果关闭系统中某一现有的仓库有什么影响 或者变换现存网络中的物料流程，成本会有何改变 105 使物流网络架构最优化的技术 数学上的最优化方法（Mathematical
15、 Optimization Techniques） -精确算法（Exact Algorithms）：一定能找出最佳解 -启发式算法（Heuristics）：能找出好的解，但未必是最优解 仿真模型（Simulation Models） -Provide a mechanism to evaluate specified design alternatives created by the designer 106 Single product Two plants p1 and p2 Plant p1 has an unlimited capacity Plant p2 has an annua
16、l capacity of 60,000 units The two plants have the same production costs There are two warehouses w1 and w2 with identical warehouse handling costs There are three markets areas c1,c2 and c3 with demands of 50,000, 100,000 and 50,000, respectively 107 WarehouseP1P2C1C2C3 W104345 W252212 Table: Distr
17、ibution Costs per Unit 108 D = 50,000 D = 100,000 D = 50,000 Cap = 60,000 $4 $5 $2 $3 $4 $5 $2 $1 $2 $0 Production costs are the same, warehousing costs are the same 109 D = 50,000 D = 100,000 D = 50,000 Cap = 60,000 $5 x 140,000 $2 x 60,000 $2 x 50,000 $1 x 100,000 $2 x 50,000 Total Costs = $1,120,
18、000 Assign each market to closet warehouse. Then assign each plant based on cost. 110 Assign each market based on total delivery cost D = 50,000 D = 100,000 D = 50,000 Cap = 60,000 $4 $5 $2 $3 $4 $5 $2 $1 $2 $0 P1 to WH1$3 P1 to WH2$7 P2 to WH1$7 P2 to WH 2$4 P1 to WH1$4 P1 to WH2$6 P2 to WH1$8 P2 t
19、o WH 2$3 P1 to WH1$5 P1 to WH2$7 P2 to WH1$9 P2 to WH 2$4 Market #1 is served by WH1, Markets 2 and 3 are served by WH2 111 D = 50,000 D = 100,000 D = 50,000 Cap = 60,000 $5 x 90,000 $2 x 60,000 $3 x 50,000 $1 x 100,000 $2 x 50,000 $0 x 50,000 P1 to WH1$3 P1 to WH2$7 P2 to WH1$7 P2 to WH 2$4 P1 to W
20、H1$4 P1 to WH2$6 P2 to WH1$8 P2 to WH 2$3 P1 to WH1$5 P1 to WH2$7 P2 to WH1$9 P2 to WH 2$4 Total Cost = $920,000 112 The problem described earlier can be framed as the following linear programming problem Let x(p1,w1), x(p1,w2), x(p2,w1) and x(p2,w2) be the flows from the plants to the warehouses x(
21、w1,c1), x(w1,c2), x(w1,c3) be the flows from the warehouse w1 to customer zones c1, c2 and c3 x(w2,c1), x(w2,c2), x(w2,c3) be the flows from warehouse w2 to customer zones c1, c2 and c3 113 The problem we want to solve is: min 0 x(p1,w1) + 5x(p1,w2) + 4x(p2,w1) + 2x(p2,w2) + 3x(w1,c1) + 4x(w1,c2) +
22、5x(w1,c3) + 2x(w2,c1) + 2x(w2,c3) Subject to the following constraints: x(p2,w1) + x(p2,w2) 99% for many products with high profit margin, high volume and low variability. Service level Low customer promise times Classic PUSH STRATEGY High shortages Huge risk PULL STRATEGY not feasible because of lo
23、ng lead times 201 OBJECTIVES: Reduce inventory and financial risks Provide customers with competitive response times. ACHIEVE THE FOLLOWING: Determining the optimal location of inventory across the various stages Calculating the optimal quantity of safety stock for each component at each stage Hybri
24、d strategy of Push and Pull Push Stages produce to stock where the company keeps safety stock Pull stages keep no stock at all. Challenge: Identify the location where the strategy switched from Push-based to Pull-based Identify the Push-Pull boundary Benefits: For same lead times, safety stock reduc
25、ed by 40 to 60% Company could cut lead times to customers by 50% and still reduce safety stocks by 30% 202 FIGURE 3-11: How to read the diagrams 203 If Montgomery facility reduces committed lead time to 13 days assembly facility does not need any inventory of finished goods Any customer order will t
26、rigger an order for parts 2 and 3. -Part 2 will be available immediately, since it is held in inventory -Part 3 will be available in 15 days 13 days committed response time by the manufacturing facility 2 days transportation lead time. Another 15 days to process the order at the assembly facility Or
27、der is delivered within the committed service time. Assembly facility produces to order, i.e., a Pull based strategy Montgomery facility keeps inventory and hence is managed with a Push or Make-to-Stock strategy. 204 FIGURE 3-12: Current safety stock location 205 FIGURE 3-13: Optimized safety stock
28、206 FIGURE 3-14: Optimized safety stock with reduced lead time 207 FIGURE 3-15: Current supply chain 208 FIGURE 3-16: Optimized supply chain 209 Identifying the Push-Pull boundary Taking advantage of the risk pooling concept Demand for components used by a number of finished products has smaller var
29、iability and uncertainty than that of the finished goods. Replacing traditional supply chain strategies that are typically referred to as sequential, or local, optimization by a globally optimized supply chain strategy. 210 FIGURE 3-17: Trade-off between quoted lead time and safety stock 211 For the
30、 same lead time, cost is reduced significantly For the same cost, lead time is reduced significantly Trade-off curve has jumps in various places Represents situations in which the location of the Push- Pull boundary changes Significant cost savings are achieved. 212 Prevalent strategy for many compa
31、nies: try to keep as much inventory close to the customers hold some inventory at every location hold as much raw material as possible. This typically yields leads to: Low inventory turns Inconsistent service levels across locations and products, and The need to expedite shipments, with resulting in
32、creased transportation costs 213 Consider a two-tier supply chain Items shipped from manufacturing facilities to primary warehouses From there, they are shipped to secondary warehouses and finally to retail outlets How to optimally position inventory in the supply chain? Should every SKU be position
33、ed both at the primary and secondary warehouses?, OR Some SKU be positioned only at the primary while others only at the secondary? 214 FIGURE 3-18: Sample plot of each SKU by volume and demand 215 High variability - low volume products Low variability - high volume products, and Low variability - l
34、ow volume products. 216 High variability low volume products Inventory risk the main challenge for Position them mainly at the primary warehouses -demand from many retail outlets can be aggregated reducing inventory costs. Low variability high volume products Position close to the retail outlets at
35、the secondary warehouses Ship fully loaded tracks as close as possible to the customers reducing transportation costs. Low variability low volume products Require more analysis since other characteristics are important, such as profit margins, etc. 217 218 在最近的一项调查报告中，要求物料和库存经理指出有效降低库存的策略。在 这调查报告中，排
36、名前七项的策略如下： 周期库存检查策略（Periodic inventory reviews） 使用率、提前期和安全存量的严格管理（Tight management of usage rates, lead times and safety stock） 减少安全库存水平（Reduced safety stock levels） 导入或实施周期盘点作业 ABC法（ABC approach） 转移更多的库存或库存所有权给供货商（Shift more inventory, or inventory ownership, to suppliers） 定量方法（Quantitative approac
37、hes） 219 预测工具和方法可归纳为以下四大类： 判断法（Judgment Methods）涉及专家意见的收集 市场研究法（Market Research Methods）涉及顾客行为的 定性研究 时间序列法（Time-Series Methods）是一种数学方法，其未 来绩效是从过去的绩效推断 因果法（Causal Methods）是一种数学方法，预测是依据数 个不同系统变量所产生 220 判断法是以系统性的方法综合不同专家的意见 一组专家可以组合起来以获取共识（Panels of experts internal, external, both） 德尔菲法（Delphi method）
38、是一种结构性的技术，在不聚集专 家到同一个地方的状况下，得到专家一致的意见 Each member surveyed Opinions are compiled Each member is given the opportunity to change his opinion 此技术的设计是为避免各决策过程中的风险和个人喜好 221 市场测试法（Market Testing）和市场调查（Market Surveys）可以是有效的方法建立预测，尤其是对新产 品而言 市场测试法：潜在顾客的焦点团体被集合且试用新产品，其反 应情况可以用来推断整个市场对产品的需求 市场调查：包括从不同潜在顾客来收集
39、这些资料，主要是透过 当面访谈、电话抽访、问卷等方式 222 时间序列法是利用过去相关数据来预测未来数据。以下为几种常 被使用方法： Moving Averages（移动平均法） -Average of some previous demand points. Exponential Smoothing（指数平滑法） -More recent points receive more weight Methods for Data with Trends（具趋势性数据的预测法） -Regression Analysis：Fits line to data -Holts Method：Combin
40、es exponential smoothing concepts with the ability to follow a trend 223 Methods for Data with Seasonality（具季节性数据的预测 法） -Seasonal Decomposition Methods：Seasonal patterns removed -Winters Method: Advanced approach based on exponential smoothing Complex methods（更多的复杂方法） -not clear that these work bett
41、er 224 根据其它非预测资料产生预测值，也就是预测值是其它 非预测数据的函数 例如下一季销售的因果预测值可能是这一季通货膨胀率 、国家生产毛额、失业率、气候等销售以外信息的函数 225 What is the purpose of the forecast? Gross or detailed estimates? What are the dynamics of the system being forecast? Is it sensitive to economic data? Is it seasonal? Trending? How important is the past i
42、n estimating the future? Different approaches may be appropriate for different stages of the product lifecycle: Testing and introduction: market research methods, judgment methods Rapid growth: time series methods Mature: time series, causal methods (particularly for long-range planning) It is typic
43、ally effective to combine approaches. Network DesignInventory Positioning and Management Resource Allocation Decision focusInfrastructureSafety stockProduction Distribution Planning HorizonYearsMonthsMonths Aggregation LevelFamilyItemClasses FrequencyYearlyMonthly/WeeklyMonthly/Weekly ROIHighMediumM
44、edium ImplementationVery ShortShortShort UsersVery FewFewFew 226 Demonstrate applicability of risk pooling and postponement, EOQ modeling, and inventory sizing to improve customer service in make-to-order job shop setting Demonstrates value from getting and looking at data 227 229 牛鞭效应牛鞭效应 有效预测有效预测
45、协调系统的信息协调系统的信息 找出所需产品找出所需产品 缩短提前期缩短提前期 信息和供应链的权衡信息和供应链的权衡 230 我们生活在信息的时代中 “In modern supply chains, information replaces inventory”（信息取代了库存） Why is this true? Why is this false? Information is always better than no information 信息如何影响供应链的设计与运作 通过有效地利用可取得的信息，我们可以比以前更有效益及 更有效率地设计与运作供应链 231 丰富的信息将 Helps
46、 reduce variability（协助减少供应链的变动性） Helps improve forecasts （协助供货商作出更好的预测） Enables coordination of systems and strategies （使制造 和分销系统与策略能够协调） Improves customer service （通过提供定位所需商品的工 具，使零售商为顾客提供更好的服务） Facilitates lead time reductions （能减少提前期） Enables firms to react more quickly to changing market conditi
47、ons （使零售商能更快地反应并适应供应方面的问题 ） 232 在供应链中愈往上游走，订单数量变动性愈增大的现象 就是牛鞭效应 Order variability is amplified up the supply chain; upstream echelons face higher variability What you see is not what they face 233 一个简单的四级供应链 一个零售商 一个批发商 一个分销商 一个工厂 234 零售商所下的订单的变动会 比顾客需求高，批发商被迫 持有较零售商多的安全库存 ，或必须要能较零售商保持 更高的能力以维持同样的服
48、务水平 235 需求预测（Demand Forecasting） Order-up-to points are modified as forecasts change orders increase more than forecasts 提前期（Lead Time） Long lead times magnify this effect 批量订购（Batching） Volume and transportation discounts 价格波动（Price Fluctuation） 被夸大的订单（Inflated Orders） IBM Aptiva orders increased b
49、y 2-3 times when retailers thought that IBM would be out of stock over Christmas Motorola cell phones 236 Exists, in part, due to the retailers need to estimate the mean and variance of demand The increase in variability is an increasing function of the lead time The more complicated the demand mode
50、ls and the forecasting techniques, the greater the increase Centralized demand information can significantly reduce the bullwhip effect, but will not eliminate it Consider a two-stage supply chain: Retailer who observes customer demand Retailer places an order to a manufacturer. Retailer faces a fix
