PQ-&-PR-分析

7.1Version5.1(6/30)“Lean”Tools7.2Version5.1(6/30)“精益”工具7.3Version5.1(6/30)PQAnalysis7.4Version5.1(6/30)PQ分析7.5Version5.1(6/30)P-QAnalysisThebestwaytobeginanefforttobuildaU-shaped“Flow”cellforwidevarietysmalllotproductionistostudythecurrentproductionconditionsthatexistinthefactory.ThisisdonethroughtheuseofaP-Qanalysis.InaP-Qanalysis,thePstandsforproductandtheQstandsforquantify(noconsiderationtodollarvalue).—Step1:Obtainatleast6monthsofdataonproductsmadeandproductionoutputquantities.(Ifknown,futureproductionquantitieswouldbebetter.)—Step2:ListtheproductsinorderofhighestquantityoutputandtheirassociatedpercentageoutputofthetotalandtabulateonaP-Qlist(seetable1).P-QAnalysisListNo.P/NQuantityTotal%Cumulative%ABBCCDEFEFFG15,90012,50011,7009,4509,4009,00015,90028,40040,10049.55058,95067,95017.513.712.910.410.39.917.531.543.754.565.274.7Table17.6Version5.1(6/30)PQ分析---要组建一个多种类小批量生产的U形“流动”工作站,首先要学习工厂内目前的生产条件.整个工作过程由PQ分析来贯穿.在PQ分析中,P代表产品,Q代表质量(不考虑货币价值)--第一步:收集至少6个月的产品资料和产量数据.如果可以的话,最好可以收集到将来的产量数据.--第二步:按照产品的产量和占总产量的百分比,由高到低给产品制PQ表.(见表1)7.7Version5.1(6/30)P-QAnalysis—Step3:CreateaP-QAnalysistable(seetable2),withtheleftverticalaxisrepresentingtheoutputquantityandthehorizontalaxisrepresentingtheproduct.ThegraphisaParetochart,listingtheproductsandtheirquantitiesindescendingorder,andacumulativepercentageline(rightverticalaxis).Note:Technically,inawidevarietysmalllotproductionshop,40%oftheproductaccountsforapproximately60%ofthevolume(orless).Intheaboveexample40%of14totalpartnumber’sisapproximately.6.Drawaverticallinethroughthe6thproductuntilyouhitthecumulative%line,anddrawahorizontallineoveruntilyouintersecttherightaxis.Inthisexampleitintersectsaround70%,andapproximatesatruewidevarietysmalllotfactory.Table2ABBCCDDEEFFGGHHIIJJKKLLMMNNO16,00014,00012,00010,0008,0006,0004,0002,000Qty..........100%80%60%40%20%..7.8Version5.1(6/30)PQ分析--第三步:制出PQ分析表(见图二),左边的纵数标表示产量,横数标表示产品.此图是一幅排列图表,产品按照产量由高到低排列,右边的纵数标是积累率.注意:从技术上来说,在多种类小批量生产的车间里,40%的产品种类应该占60%的生产总量.在上面的例子中,总共有14种零部件,它的40%约等于6,于是就在第六个产品上面画上一条竖线与积累率线相交,然后在交叉点开始画一条水平线与右边的纵数标交叉.在这个事例中,他们的交叉点为70%,接近多种类小批量生产车间的生产实况.Table2ABBCCDDEEFFGGHHIIJJKKLLMMNNO16,00014,00012,00010,0008,0006,0004,0002,000Qty..........100%80%60%40%20%..7.9Version5.1(6/30)P-QAnalysis—Step4:DesignalineofprocessesbasedontheP-QAnalysislist.IftheP-QAnalysisshowsthat20%ofthepartsrepresent80%ofthevolume;theneachproductshouldbeinvestigatedforasingleproductcell(therelativevolumeprobablyalreadyrequiresdedicatedequipment).7.10Version5.1(6/30)第四步:根据PQ分析制作图表,如果PQ分析显示20%的产品占有80%的生产总量,那么每个产品都应该有单独的生产区(或许相对产量已经要求专门的设备).PQ分析7.11Version5.1(6/30)P-QAnalysisInawidevarietysmalllotfactorydepictedbelow(seetable3),GroupTechnologyorfamiliesmustbeidentifiedthroughtheuseofaProcess-Route(PR)Analysis(describedinthenextsection).Inthediagrambelowofawidevarietyfactory,GroupApartstypicallyrepresentabout70%ofthevolumeandcanwarrantaspecializedsingleproductline.ProductsfallingintogroupsB&Crepresenttheremaining30-39%,andwillbereviewedforagrouporfamily.Table3WideVariety—SmallLotProductionAgroup:about70%Bgroup:About70%to95%Cgroup:about95%to99%•Specializedline•“Quantity—buildingline”GroupTechnologylineProductmodel—buildinglineQPABC•Noline7.12Version5.1(6/30)Table3WideVariety—SmallLotProductionAgroup:about70%Bgroup:About70%to95%Cgroup:about95%to99%•Specializedline•“Quantity—buildingline”GroupTechnologylineProductmodel—buildinglineQPABC•Noline在多种类小批量生产的工厂里(如图3所示),通过对工艺路线的分析,识别成组技术和产品系列(下部分会讲到).在下面的图表里,A组部件占了生产总量的70%.这就说明了需要一条单独的生产线.B组和C组的产品占了30%--39%,我们将把他们作为一组或是一个系列.PQ分析7.13Version5.1(6/30)PRAnalysisThenextstepistoanalyzetheflowofproductingroupA(asastartingpoint),todetermineifotherproductsfollowasimilarprocesspathandcouldbeconsideredafamily.—Whenconsideringfamiliesviaaprocess-route(PR)analysis,donotconsiderdifferencesinproductshape,size,ormaterialasdifferentvarietiesofparts,butratherpartsthatfollowthesamebasicprocessflowsequence.Mostfactorieshavenomorethan5suchprocessfamilies.Whengroupingseveraldifferentpartstogetherintoafamily(GroupTechnology),thekeyfactorbecomeschangeover,whichmustbedrasticallyreduced.—TypicallyGroupB&Cpartsfallintothiscategory,comprisingdifferentproductsthathavesimilarprocesspathsandcanthereforeusethesameline/cellconfiguration.ProcessPathTableLocation:Fabrication-Plant1Date:9/4/00ProcessMachineNo.No.ItemPressPressPunchDrillTurnBendCleanMarkInspectShip123451997M451997M441997M491997M341997M1061997M14P1P2P3P4P5P6BenchBenchDockCentral00000000000000000000000000000000000000000007.14Version5.1(6/30)ProcessPathTableLocation:Fabrication-Plant1Date:9/4/00ProcessMachineNo.No.ItemPressPressPunchDrillTurnBendCleanMarkInspectShip123451997M451997M441997M491997M341997M1061997M14P1P2P3P4P5P6BenchBenchDockCentral0000000000000000000000000000000000000000000下一步就是分析A组产品的流程(作为起点),然后再决定其他产品的流程是否与它相似以及是否能够归为同一系列.---通过工艺流程分析考虑成组时,不要认为产品形状,尺寸,或是材料的不同就是产品种类的不同,事实上它们的基本流程顺序都是一样的.大多数工厂最多有5个不同的工艺系列.当把几种不同的部件归组为一系列(成组技术)时,主要因素就会发生改变,我们应该尽量减少变化.---B和C组部件通常归为一组,其中包括有着类似流程途经和能够使用相同生产线/工作站生产的产品.PR分析7.15Version5.1(6/30)PRAnalysisTofilloutthePRAnalysisform,listtheope