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1、运输决策运输决策Transport DecisionsCR(2004)Prentice Hall,Inc.第七章第七章Chapter 7If you are planning for one year,grow rice.If you are planning for 20 years,grow trees.If you are planning for centuries,grow men.A Chinese proverb2021/9/241产品计划三角形产品计划三角形Product in the Planning TriangleCR(2004)Prentice Hall,Inc.PLA
2、NNINGORGANIZINGCONTROLLINGTransport Strategy Transport fundamentals Transport decisionsCustomer service goals The product Logistics service Ord.proc.&info.sys.Inventory Strategy Forecasting Inventory decisions Purchasing and supply scheduling decisions Storage fundamentals Storage decisionsLocation
3、Strategy Location decisions The network planning process 计划计划 组织组织 控制控制Transport Strategy Transport fundamentals Transport decisionsCustomer service goalsThe product Logistics service Ord.proc.&info.sys.Inventory Strategy Forecasting Inventory decisions Purchasing and supply scheduling decisions Sto
4、rage fundamentals Storage decisionsLocation Strategy Location decisions The network planning process 库存战略 预测客户服务目标采购和供应时间决策存储基础知识存储决策产品物流服务订单管理和信息系统 库存决策 运输战略 运输基础知识 运输决策 选址战略 选址决策 网络规划流程2021/9/242Transport Decisionsin Transport StrategyPLANNINGORGANIZINGCONTROLLINGTransport Strategy Transport funda
5、mentals Transport decisionsCustomer service goals The product Logistics service Ord.proc.&info.sys.Inventory Strategy Forecasting Inventory decisions Purchasing and supply scheduling decisions Storage fundamentals Storage decisionsLocation Strategy Location decisions The network planning processPLAN
6、NINGORGANIZINGCONTROLLINGTransport Strategy Transport fundamentals Transport decisionsCustomer service goals The product Logistics service Ord.proc.&info.sys.Inventory Strategy Forecasting Inventory decisions Purchasing and supply scheduling decisions Storage fundamentals Storage decisionsLocation S
7、trategy Location decisions The network planning processCR(2004)Prentice Hall,Inc.2021/9/243Just a few of the many problems in transportation典型的运输决策典型的运输决策Typical Transport DecisionsCR(2004)Prentice Hall,Inc.模式、服务选择模式、服务选择Mode/Service selection Private fleet planning -路线选择Carrier routing-多起迄点问题Routin
8、g from multiple points-Routing from coincident origin-destination points起迄点重合问题-车辆线路和时刻表Vehicle routing and scheduling Freight consolidation 2021/9/2447.1运输服务的选择n7.1.1基本的成本权衡nCost typesn运输运输Transportationn在途库存在途库存In transit inventoryn工厂库存工厂库存Source inventoryn基层库存基层库存Destination inventoryn7.1.2考虑竞争因素
9、考虑竞争因素n7.1.3对选择方法的评价对选择方法的评价2021/9/245方式选择方式选择Mode/Service Selection(Contd)Example Finished goods are to be shipped from a plant inventory to a warehouse inventory some distance away.The expected volume to be shipped in a year is 1,200,000 lb.The product is worth$25 per lb.and the plant and carrying
10、 costs are 30%per year.Other data are:CR(2004)Prentice Hall,Inc.Transport choice Rate,$/lb.Transit time,days Shipment size,lb.Rail 0.11 25 100,000 Truck 0.20 13 40,000 Air 0.88 1 16,000 2021/9/246Include transport rateTransport Selection AnalysisCosttypeCompu-tationRailTruckAirTrans-portationRD.11(1
11、,200,000)=$132,000.20(1,200,000)=$240,000.88(1,200,000)=$1,056,000In-transitinventoryICDT365.30(25)1,200,000(25)/365=$616,438.30(25)1,200,000(13)/365=$320,548.30(25)1,200,000(1)/365=$24,658PlantinventoryICQ2.30(25)100,000/2=$375,000.30(25)40,000/2=$150,000.30(25)16,000/2=$60,000WhseinventoryICQ2.30(
12、25.11)100,000/2=$376,650.30(25.20)40,000/2=$151,200.30(25.88)16,000/2=$62,112 Totals$1,500,088$861,748$1,706,770Improved serviceCR(2004)Prentice Hall,Inc.7-62021/9/2477.2路线选择n基本类型n一是起讫点不同的单一路径规划n二是多个起讫点的路径规划n三是起点和终点相同的路径规划2021/9/2487.2.1 起讫点不同的单一路径问题n已知一个由链和节点组成的网络,其中已知一个由链和节点组成的网络,其中节点代表由链连接的点,链代表节
13、点之节点代表由链连接的点,链代表节点之间的成本(距离、时间或距离和时间的间的成本(距离、时间或距离和时间的加权平均)。最初,所有的节点都是未加权平均)。最初,所有的节点都是未知解,只有起点是已解的节点。知解,只有起点是已解的节点。2021/9/249n第第n次迭代的目的。找出第次迭代的目的。找出第n个距起点最近的节点。对个距起点最近的节点。对,重复此过程,直到所找出的最近,重复此过程,直到所找出的最近节点是终点。节点是终点。n第次迭代的输入值。在前面的迭代过程中找出(第次迭代的输入值。在前面的迭代过程中找出(n-1)距起点最近的节点,及其距起点最短的路径和距离。距起点最近的节点,及其距起点最短
14、的路径和距离。这些节点和起点统称为已解的节点,其余的称为未解这些节点和起点统称为已解的节点,其余的称为未解的节点。的节点。2021/9/2410n第第n个最近节点的候选点。每个已解的节点直接和一个或多个未个最近节点的候选点。每个已解的节点直接和一个或多个未解的节点相连接,就可以得出一个候选点连接距离最短的未解的节点相连接,就可以得出一个候选点连接距离最短的未解点。如果有多个距离相等的最短路径连接,则有多个候选点。解点。如果有多个距离相等的最短路径连接,则有多个候选点。n计算出第个最近的节点。将每个已解节点与其候选节点之间的计算出第个最近的节点。将每个已解节点与其候选节点之间的距离累加到该已解节
15、点与起点之间最短路径的距离上。所得出的距离累加到该已解节点与起点之间最短路径的距离上。所得出的总距离最短的候选点就是地总距离最短的候选点就是地n个最近的节点,其最短路径就是得个最近的节点,其最短路径就是得出该距离的路径。若多个候选点都得出相等的最短距离,则都是出该距离的路径。若多个候选点都得出相等的最短距离,则都是已解的节点。已解的节点。2021/9/2411OriginAmarilloOklahomaCityDestinationFort WorthABEICDGFHJ90 minutes848413834815648132150126132120661264860Note:All link
16、 times are in minutes90Carrier Routing(Contd)Can be a weighted index of time and distanceCR(2004)Prentice Hall,Inc.2021/9/2412Shortest Route MethodCR(2004)Prentice Hall,Inc.Step Solved Nodes Directly Connected to Unsolved Nodes Its Closest Connected Unsolved Node Total Cost Involved nth Nearest Node
17、 Its Minimum Cost Its Last Connectiona 1 A B 90 B 90 AB*2 A C 138 C 138 AC B C 90+66=156 3 A D 348 B E 90+84=174 E 174 BE*C F 138+90=228 4 A D 348 C F 138+90=228 F 228 CF E I 174+84=258 5 A D 348 C D 138+156=294 E I 174+84=258 I 258 EI*F H 228+60=288 6 A D 348 C D 138+156=294 F H 228+60=288 H 288 FH
18、 I J 258+126=384 7 A D 348 C D 138+156=294 D 294 CD F G 288+132=360 H G 288+48=336 I J 258+126=384 8 H J 288+126=414 I J 258+126=384 J 384 IJ*2021/9/2413MAPQUEST SOLUTIONMapquest at CR(2004)Prentice Hall,Inc.2021/9/2414Plant 1Requirements=600Plant 2Requirements=500Plant 3Requirements=300Supplier ASu
19、pply 400Supplier CSupply 500Supplier BSupply 7004a76555958aThe transportation rate in$per ton for an optimal routing between supplier A and plant 1.7.2.2多起讫点问题多起讫点问题Routing from Multiple PointsThis problem is solved by the traditional transportation method of linear programmingCR(2004)Prentice Hall,
20、Inc.2021/9/2415TRANLP problem setupSolutionCR(2004)Prentice Hall,Inc.2021/9/24167.2.3起迄点重合问题n配送饮料到酒吧和饭店n安排时间线路将现钞送到自动提款机n收集饭店的油脂n网上杂货店的配送n从仓库到零售点的配送n邮车的配送线路n校车线路2021/9/24171.各点空间相连各点空间相连CR(2004)Prentice Hall,Inc.不好的路线规划-线路交叉好的路线规划-线路不交叉2021/9/2418Routing with a Coincident Origin/Destination Point Ty
21、pical of many single truck routing problems from a single depot.Mathematically,a complex problem to solve efficiently.However,good routes can be found by forming a route pattern where the paths do not cross a tear drop pattern.CR(2004)Prentice Hall,Inc.2021/9/2419Single Route Developed by ROUTESEQ i
22、n LOGWARE0 1 2 3 4 5 6 7 8876543210X coordinates1231911121314151617184567891020DY coordinates0 1 2 3 4 5 6 7 8876543210X coordinates1231911121314151617184567891020DY coordinates(a)Location of beverage accountsand distribution center(D)withgrid overlay(b)Suggested routing patternCR(2004)Prentice Hall
23、,Inc.7-142021/9/24202.空间上不相连点的问题n感知方法基本不适用,必须借助于多年来人们提出的数学方法来解决这类问题2021/9/24217.3 行车路线和时刻表的确定行车路线和时刻表的确定CR(2004)Prentice Hall,Inc.每个站点都要取送货有不同运载能力的车辆的组合司机工作时间限制时间窗口限制途中只能送货后再收货驾驶员特定时间休息和用餐2021/9/24227.3.1合理路径和时刻表的制定原则n安排车辆负责相互距离最接近的站点的货物运输。安排车辆负责相互距离最接近的站点的货物运输。n安排车辆各日的途径站点时,应注意使站点群更加紧凑安排车辆各日的途径站点时,
24、应注意使站点群更加紧凑n从距仓库最远的站点开始设计从距仓库最远的站点开始设计n卡车的行车路线应呈水滴状卡车的行车路线应呈水滴状n尽可能选用最大的车辆送货,这样设计出的路线是最有效的尽可能选用最大的车辆送货,这样设计出的路线是最有效的2021/9/2423n取货、送货应该混合安排,不应该在完成全部送货任务之后再取货n对过于遥远而无法归入群落的站点可以采用其他配送方式n避免时间窗口过短2021/9/2424划分站点群以分派车辆划分站点群以分派车辆1.安排车辆负责相互距离最接近的站点的货物运输(a)不合理的划分方式Weak clusteringDepot(b)较合理的划分方式Better clust
25、eringDDDepotStopsCR(2004)Prentice Hall,Inc.2021/9/2425Guidelines(Contd)2.对不同日期划分站点群FFFFFFFTTTTTTTDDepotFFFFFTTTFTFTTTDDepot(a)不合理的划分-线路交叉routes cross(b)Better clusteringStop可能需要配合销售实现群的划分CR(2004)Prentice Hall,Inc.2021/9/2426Guidelines(Contd)2.Stops on different days should be arranged to produce tig
26、ht clustersFFFFFFFTTTTTTTDDepotFFFFFTTTFTFTTTDDepot(a)Weak clustering-routes cross(b)Better clusteringStopMay need to coordinate with sales to achieve clustersCR(2004)Prentice Hall,Inc.2021/9/2427Application of Guidelines to Casket DistributionWarehouseFuneral homeTypical weekly demand and pickupsCR
27、(2004)Prentice Hall,Inc.2021/9/2428Application of Guidelines to Casket Distribution(Contd)WarehouseFuneral homeDivision of sales territories into days of the weekTerritories of equal size to minimize number of trucksCR(2004)Prentice Hall,Inc.2021/9/2429Application of Guidelines to Casket Distributio
28、n(Contd)WarehouseFuneral home地区内的路线设计Route design within territoriesCR(2004)Prentice Hall,Inc.2021/9/24307.3.2行车路线和时刻表的制定方法n1.扫描法n2.节约法2021/9/24311.扫描法n(1)在地图或方格图中确定所有站点(含仓库)的位置n(2)自仓库始沿任一方向向外划一条直线n(3)排定各线路上每个站点的顺序使行车距离最短。2021/9/24321.扫描法扫描法“Sweep”Method for VRPExample A trucking company has 10,000-
29、unit vans for merchandise pickup to be consolidated into larger loads for moving over long distances.A days pickups are shown in the figure below.How should the routes be designed for minimal total travel distance?CR(2004)Prentice Hall,Inc.2021/9/2433GeographicalregionDepot1,0002,0003,0002,0004,0002
30、,0003,0003,0001,0002,0002,0002,000PickuppointsStop Volume and LocationCR(2004)Prentice Hall,Inc.2021/9/2434Sweep directionis arbitraryDepot1,0002,0003,0002,0004,0002,0003,0003,0001,0002,0002,0002,000Route#110,000 unitsRoute#29,000 unitsRoute#38,000 units“Sweep”Method SolutionCR(2004)Prentice Hall,In
31、c.2021/9/24352.节约法n目标使所有车辆行驶的总里程最短,并进而使为所有站点提供服务的卡车数量最少。2021/9/2436The“Savings”Method for VRPDepotDepot(a)Initial routing Route distance=d0,A+dA,0+d0,B+dB,0(b)Combining two stops on a route Route distance=d0,A+dA,B+dB,0ABdA,0d0,Ad0,BdB,0ABdB,0d0,AdA,BStopStop00“Savings”is better than“Sweep”methodhas
32、 lower average errorCR(2004)Prentice Hall,Inc.7-252021/9/2437节约法求解配送方案n例题:下图为某配送中心的配送网络,途中P点为配送中心,AJ为配送客户,共10位客户,括号内为配送货物吨数,线路上的数字为道路距离,单位为km。n现配送中心有额定载重量分别为2t和4t两种箱式货车可供送货,试用节约法设计最佳送货路线。2021/9/2438(1.4)PCBAJDEFIGH(1.5)76(0.4)(1.5)(0.7)(0.5)(0.8)(0.6)(0.6)2554119264587691047810434365(0.8)2021/9/2439
33、n解:第一步,计算网络结点间的最短距离(可采用最短路求解法)。计算结果如表1。表1:最短配送线路表PA10AB94BC795CD814105DE8181496EF8181715137FG313121011106GH4141311121282HI10111517181817119IJ74813151515101182021/9/2440n第二步,根据最短路结果,计算出各客户之间的节约里程,结果如表2。n计算举例:AB的节约里程:nPA的距离10,PB的距离9,AB的距离4n则AB的节约里程为10+94=15 2021/9/2441表2 配送路线节约里程表AB15BC811CD4710DE0331
34、0EF00039FG000015GH0000045HI94000125IJ13810000092021/9/2442n第三步,对节约行程按照大小顺序进行排列,如表3所示。表3:节约里程排序表序号连接点节约里程序号连接点节约里程1AB1513FG52AJ1314GH53BC1115HI54CD1016AD45DE1017BI46AI918FH47EF919BE38IJ920DF39AC821GI210BJ822GJ111BD723EG112CE624FI12021/9/2443第四步,按节约里程排列顺序表,组合成配送路线图。n配送路线为:n线路一:PJABCP,需一辆4t货车。n线路二:PDEF
35、GP,需一辆4t货车。n线路三:PHIP,需一辆2t货车。2021/9/2444PCBAJDEFIGH(1.5)(1.4)76(0.4)(1.5)(0.7)(0.5)(0.8)(0.6)(0.6)25496760471043(0.8)配送线路二配送线路一配送线路三2021/9/2445n节约法的注意事项n(1)适用于有稳定客户群的配送中心;n(2)各配送线路的负荷要尽量均匀;n(3)实际选择线路时还要考虑道路状况;n(4)要考虑驾驶员的作息时间及客户要求的交货时间;n(5)可利用计算机软件进行运算,直接生成结果。2021/9/2446节约法观察节约法观察在同一条路线上,能够提供最大节约量的点是
36、那些离仓库最远的并且相互最接近的地方。构建多站线路的原则CR(2004)Prentice Hall,Inc.2021/9/2447Savings Method ObservationThe points that offer the greatest savings when combined on the same route are those that are farthest from the depot and that are closest to each other.This is a good principle for constructing multiple-stopr
37、outesCR(2004)Prentice Hall,Inc.2021/9/24487.3.3运输线路排序运输线路排序89101112123456Route#1Route#10AMPMRoute#6Route#9Route#4Route#5Route#8Route#2Route#7Route#3Truck#1Truck#2Truck#3Truck#4Truck#5Minimize number of trucks by maximizing number of routes handled by a single truckCR(2004)Prentice Hall,Inc.7-49对行车路线
38、排序以尽可能减少所需卡车数2021/9/2449Route Sequencing in VRP89101112123456Route#1Route#10AMPMRoute#6Route#9Route#4Route#5Route#8Route#2Route#7Route#3Truck#1Truck#2Truck#3Truck#4Truck#5Minimize number of trucks by maximizing number of routes handled by a single truckCR(2004)Prentice Hall,Inc.7-502021/9/2450n方法之一是
39、三阶段法方法之一是三阶段法n1.预览:分析人员预览实际问题,考察有预览:分析人员预览实际问题,考察有无例外情况。无例外情况。n2.求解:通常借助于计算机求解:通常借助于计算机n3.审核:分析人员对数学求解结果进行审审核:分析人员对数学求解结果进行审核,根据实际情况对结果加以修正。核,根据实际情况对结果加以修正。7.3.4行车路线和时刻表制定方法的应用行车路线和时刻表制定方法的应用7-512021/9/24517.4船舶航线和船期计划n某欧洲炼油企业沿欧洲海岸线有三个炼油厂D1,D2,D3,所用原油来自中东的两个港口L1,L2,装货港和卸货港之间采用油轮运输原油。以天数计算的港口间航行时间由以下
40、矩阵给出:航行时间加装货时间卸货点D1D2D3装货点L1211913装货点L21615122021/9/2452n为简化问题,假定港口间的航行时间与航行方向无关,且装卸时间相等,根据以后两个月的需求情况,炼油厂要求货物在下列时间运到,从现在开始计起:自L2L1L1L2到D3D1D2D3到达时间122951612021/9/2453n根据给出的装货时间和航行时间,要满足卸货日期的要求,必须在如下时间装货:n最晚装货时间到D1D2D3自L1832-自L2-0,492021/9/2454n“行行”代表最终状态,代表最终状态,“列列”代表起始状态。供求值是每种状态代表起始状态。供求值是每种状态发生的次
41、数。本例中,所有的供求值都是发生的次数。本例中,所有的供求值都是1.矩阵中只有某些单元矩阵中只有某些单元格有可行解,例如第四行第二列单元格的解就不可行。因为油轮格有可行解,例如第四行第二列单元格的解就不可行。因为油轮不可能在第不可能在第61天卸货后,再在第天卸货后,再在第8天装货。用这种方式检验所有天装货。用这种方式检验所有的单元格,对于不可行的单元格就指定一个非常高的成本,如的单元格,对于不可行的单元格就指定一个非常高的成本,如100个成本单位,使其无法求解。对于可行的单元格就确定一个个成本单位,使其无法求解。对于可行的单元格就确定一个较低的成本,如较低的成本,如1个成本单位。对于空闲的单元
42、格则指定比较高个成本单位。对于空闲的单元格则指定比较高的成本,如的成本,如10个成本单位,以限制其使用。对空闲单元格进行初个成本单位,以限制其使用。对空闲单元格进行初始分派就可以得到问题的初始可行解。这个解代表所需船只数量始分派就可以得到问题的初始可行解。这个解代表所需船只数量的最大值。的最大值。2021/9/2455以运输方法解决船期安排问题的初始解L20L18L132L249空置需求D3121001001110/11D129100100100110/11D25110010010010010/11D36110010010010010/11空置10/110/110/110/110/04供给11
43、1142021/9/2456n从第一列的初始状态开始,找到第一行最终状态解值为从第一列的初始状态开始,找到第一行最终状态解值为1 的单元的单元格,这就是位于第一行第三列的单元格。然后,我们找到另一个格,这就是位于第一行第三列的单元格。然后,我们找到另一个解值是解值是1 的单元格,即第三行第五列的单元格,这是一个空闲单的单元格,即第三行第五列的单元格,这是一个空闲单元格,随后停止。再从下一列开始重复上述过程,直到找到空闲元格,随后停止。再从下一列开始重复上述过程,直到找到空闲行内所有解值为行内所有解值为1的空闲单元格。第一条线路就是的空闲单元格。第一条线路就是L2,0-D3,12-L1,32-D
44、2,51.nL1,8-D1,29-L2,49-D3,61.由于有两条不同的运输路线,因此需要由于有两条不同的运输路线,因此需要两艘油轮。两艘油轮。2021/9/2457船期计划问题解的矩阵L20L18L132L249空置需求D3121001001110/11D129100100100110/11D25110010010010010/11D36110010010010010/11空置10/110/110/110/110/04供给111142021/9/24587.5Freight Consolidation合并运输合并运输库存合并车辆合并仓库合并时间合并CR(2004)Prentice Hall
45、,Inc.2021/9/24597.5Freight Consolidation合并运输合并运输Combine small shipments into larger onesA problem of balancing cost savings against customer service reductionsAn important area for cost reduction in many firmsBased on the rate-shipment size relationship for for-hire carriersCR(2004)Prentice Hall,Inc
46、.2021/9/2460Freight Consolidation AnalysisCR(2004)Prentice Hall,Inc.Suppose we have the following orders for the next three days.Consider shipping these orders each day or consolidating them into one shipment.Suppose that we know the transport rates.Note:Rates from an interstate tariffFrom:Ft WorthD
47、ay 1 Day 2 Day 3 To:Topeka5,000 lb.25,000 lb.18,000 lb.Kansas City7,00012,00021,000 Wichita42,00038,00061,0002021/9/2461Freight Consolidation Analysis(Contd)Day 1 Day 2 Rate x volume=costRate x volume=costTopeka3.42 x 50 =$171.001.14 x 250=$285.00Kansas City3.60 x 70 =252.001.44 x 120=172.80Wichita0
48、.68 x 420 =285.60 0.68 x 400a=272.00 Total$708.60 Total$729.80a Ship 380 cwt.,as if full truckload of 400 cwt.Day 3 Totals Rate x volume=costTopeka1.36 x 180=$244.80$700.80Kansas City1.20 x 210=252.00 676.80Wichita0.68 x 610=414.80 972.40 Total$911.60$2,350.00Separate shipmentsCR(2004)Prentice Hall,
49、Inc.7-302021/9/2462Freight Consolidation Analysis(Contd)a 480=50+250+180Computing transport cost for one combined,three-day shipmentCheaper,but what aboutthe service effects of holdingearly orders for a longer timeto accumulate larger shipmentsizes?Consolidated shipment Day 3 Rate x volume=costTopeka0.82 x 480a =$393.60Kansas City0.86 x 400 =344.00Wichita0.68 x 1410 =958.80 Total$1,696.40CR(2004)Prentice Hall,Inc.7-312021/9/2463