[经管营销]Lecture 2 物流网络配置.ppt

Lecture 2. 物流网络配置,Outline,什么是物流网络配置? 方法 建模 数据整合 验证 求解方法,物流网络,物流网络包括: 中间环节: 供应商，制造商，仓库/配送中心和顾客 在以上中间环节中流动的原材料，WIP (Work in Process, 在制品) 和 产成品.,Supply,Sources: plants vendors ports,Regional Warehouses: stocking points,Field Warehouses: stocking points,Customers, demand centers sinks,Production/ purchase costs,Inventory & warehousing costs,Transportation costs,Inventory & warehousing costs,Transportation costs,决策分类,战略性规划: 进行重大投资并具有长期效应的决策性行为 决定新工厂、配送中心和仓库的数目、位置和规模 工厂内部新生产设备的购买和设计 运输设备、通讯设备和数据处理方法等的设计,决策分类,战术性规划: 数月内的制造资源和配送资源安排计划 库存策略 配送策略 运输策略,决策分类,运作控制: 每天的运作决策 生产调度 订单分配、跟踪和处理 车辆调度,网络设计：关键性问题,选择工厂/仓库的最优的数目、位置和规模 决定最优的采购策略 哪个工厂/供应商提供哪种产品 决定最优的配送渠道 哪个仓库服务客户,网络设计：关键性问题,目标是平衡服务水平和下列因素： 生产/采购成本 库存持有成本 设备成本(持有成本和固定成本) 运输成本 也就是说，我们需要找到配送网络的一个最优年成本结构，同时以一定的服务水平满足市场需求.,网络设计的主要工具,Mapping (图示化工具) 图形化显示供应链情况和网络设计结果 图形化显示各种结果，帮助用户直观理解各种情况 数据 供应链各项成本的数据 计算 优化方法,Mapping Allows You to Visualize Your Supply Chain,Displaying the Solutions Allows you To Compare Scenarios,网络设计涉及数据,1. 工厂数据 2. 客户位置 3. 客户需求 4. 运输费率 5. 库存成本 6. 运量 7. 订单频率、规模等 8. 订单处理成本 9. 服务目标,数据实在太多了,顾客汇集,采用网格或聚类技术将距离较近的顾客集合起来。在一个单元格内的所有顾客看作是一个单一顾客. We refer to a cell as a customer zone (顾客区域).,顾客汇集的影响,顾客区域平衡了 由于汇集造成的计算误差 计算的复杂性 什么会影响汇集的效果? 汇集点，也就是不同区域的数目 在每个区域内顾客的分布情况,推荐方法,汇集点在150200. 每个汇集点的需求基本相同. 将汇集点放在区域的中心 依次进行，通常误差不超过1%,顾客汇集测试,一个工厂；一个产品 只考虑运输成本 顾客数据 原始数据有18000个5位邮编的市场区域 汇集成800个3位邮编的市场区域 总需求都是一样的,比较,Total Cost:$5,796,000 Total Customers: 18,000,Total Cost:$5,793,000 Total Customers: 800,Cost Difference 0.05%,产品汇集,公司的产品线可能有成百上千种产品类型 可能是产品型号和样式的不同 可能是包装的不同(尽管是同样的产品) 对于所有的产品，收集数据并进行分析是不现实的,产品汇集的一种方法,按照单品SKUs (Stock Keeping Unit)对产品进行分类 利用单品的如下物流特征进行分类 重量 体积 库存持有成本,Within Each Source Group, Aggregate Products by Similar Characteristics,矩形表明了对SKU的汇集,产品汇集测试,5 个工厂 25 个待选仓库地点 基于距离的服务要求 库存持有成本 固定仓库成本 产品汇集 46 种产品 汇集成为4种,比较,Total Cost:$104,564,000 Total Products: 46,Total Cost:$104,599,000 Total Products: 4,Cost Difference: 0.03%,其它问题,未来需求 设备成本 固定成本: 与仓库货物流动量不成正比 管理成本: 人力成本, 设备成本 存储成本: 与库存水平成比例,Supply,Sources: plants vendors ports,Regional Warehouses: stocking points,Field Warehouses: stocking points,Customers, demand centers sinks,Production/ purchase costs,Inventory & warehousing costs,Transportation costs,Inventory & warehousing costs,Transportation costs,在保证服务水平的前提下 最小化物流成本,Optimal Number of Warehouses,增加仓库数目的影响,仓库数目的增加会缩短对顾客的服务时间，提高服务水平 造成安全库存的增加，继而导致库存成本的上升 增加管理成本 在一定程度上会降低运输成本 降低outbound运输成本 会增加 inbound运输成本,Industry Benchmarks: 配送中心的数目,Sources: CLM 1999, Herbert W. Davis LogicTools,Avg. # of WH,3,14,25,医药行业,食品行业,化工行业,- 高利润产品 - 服务不重要 (或者易于快运) - 相对运输，库存成本更高,- 低利润产品 - 服务很重要（或者不易快运） - Outbound运输较inbound更贵,一个典型的网络设计模型,Several products are produced at several plants. Each plant has a known production capacity. There is a known demand for each product at each customer zone. The demand is satisfied by shipping the products via regional distribution centers. There may be an upper bound on total throughput at each distribution center.,一个典型的选址模型,There may be an upper bound on the distance between a distribution center and a market area served by it A set of potential location sites for the new facilities was identified Costs: Set-up costs Transportation cost is proportional to the distance Storage and handling costs Production/supply costs,网络设计问题的复杂性,Location problems are, in general, very difficult problems. The complexity increases with the number of customers, the number of products, the number of potential locations for warehouses, and the number of warehouses located.,解方法,Mathematical optimization techniques: Exact algorithms: find optimal solutions Heuristics: find “good” solutions, not necessarily optimal Simulation models: provide a mechanism to evaluate specified design alternatives created by the designer.,启发式算法和精确算法,Single product Two plants p1 and p2 Plant P1 has an annual capacity of 200,000 units. Plant p2 has an annual 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.,启发式算法和精确算法,Why Optimization Matters?,D = 50,000,D = 100,000,D = 50,000,Cap = 60,000,Cap = 200,000,$4,$5,$2,$3,$4,$5,$2,$1,$2,生产成本相同, 库存成本也相同,$0,Traditional Approach #1: Assign each market to closet WH. Then assign each plant based on cost.,D = 50,000,D = 100,000,D = 50,000,Cap = 60,000,Cap = 200,000,$5 x 140,000,$2 x 60,000,$2 x 50,000,$1 x 100,000,$2 x 50,000,Total Costs = $1,120,000,Traditional Approach #2: Assign each market based on total landed cost (到岸成本),D = 50,000,D = 100,000,D = 50,000,Cap = 60,000,Cap = 200,000,$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 to WH 2 $3,P1 to WH1 $5 P1 to WH2 $7 P2 to WH1 $9 P2 to WH 2 $4,Traditional Approach #2: Assign each market based on total landed cost,D = 50,000,D = 100,000,D = 50,000,Cap = 60,000,Cap = 200,000,$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 to 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,Traditional Approach #2: Assign each market based on total landed cost,D = 50,000,D = 100,000,D = 50,000,Cap = 60,000,Cap = 200,000,$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 WH1 $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 = $920,000,什么是线性规划?,什么是线性规划?,最优策略,Two Types of Warehouse Location Models,P-median allocation model (p-中值选址模型) Maximal covering model (交通圈最大覆盖模型),P-Median Allocation Model,需求点,仓库候选点,P=3,在给定数量和位置的需求点集合和一个候选的仓库位置集合下，分别对p个仓库找到合适的位置并指派每个需求点到一个特定的仓库，使仓库和需求点之间的配置达到最优化的目标。（目标可以是运输总费用的最低，也可以是运输的总时间最低，等。）,P-Median Allocation Model,Objective function:,N=1,2,n, n demand points M=1,2,m, m potential warehouse locations di: demand of demand point i p: 可建仓库的总数目(pm) cij: 从需求点i到仓库建库点 j 的单位运输费用或时间，等,总运输