程序基线相关知识简介.ppt

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1、PlanningProcessBaselining程序基线CollectingDatatoCharacterizetheCurrentProcessOutput(Y)Theobjectiveistoreporthowtheprocessisperformingatpresent.ShortTermVariationLongtermprocesscapabilityVariationCenteringStabilityHowaretheindependentvariableschangingastheprocessrunsitscourse?Datacollectio

2、nwillbedesignedtoanswerthesequestions3收集数据用以描述目前程序结果(Y)以汇报目前程序运行情况为目标。短期差异长期程序能力差异集中稳定各独立的变量是如何在程序运行过程中发生差异的。数据收集专为回答这些问题而设计。4TheEffectsofVariationTherearetwotypesofvariation.CommonCauseVariationVariationthatisinherentintheexistingprocessAssignable(Special)CauseVariationVariationthatca

3、nbesegregatedandassignedtoaspecificcause.Ourprocessanalysismethodswillbeplannedtoenableustoseparateandevaluatebothkindsofvariation.5差异的影响差异存在两种。常规原因的差异差异固定存在于现有程序中。（特殊）原因的差异差异可以被隔离并被归因于一特定原因。程序分析方法将使我们能有效分离及评估两种差异。6CommonCauseVariationThisvariationispresentineveryprocess.Itcannotbecont

4、rolledorreducedwiththeexistingtechnology.Itlimitstheprocesscapability.Inprocessbaselining,wemeasurethisvariationbytheamountofvariationintheshorttermsubgroups,oftencalledrationalsubgroups.sSTwillrecordthecommoncausevariationandZSTwillreporttheShortTermCapability.AnothertermforCommonCaus

5、eVariationisResidual.Sincethisvariationisrelatedtoprocesstechnology,apoorZSTwillgenerallyindicateaneedforaddressingpartorprocessdesignissues.7常规原因的差异此差异存在于每一程序中。运用现有技术是不能控制或减少此差异。此差异限制了程序能力。在程序基线内，我们运用短期子群内的差异量来测量差异，短期子群即为通常所称的合理子群。sST记录常规差异，ZST报告短期能力。常规原因的差异的另一术语为残差。由于差异与程序技术相关联，因此一个相

6、对差的ZST会显示需要重新描述部分程序设计。8AssignableCauseVariationThisvariationistheresultofoutsideinfluencesonaprocessthatcauseittoshiftanddrift.ItispotentiallycontrollablewiththeexistingtechnologyItwillaffecttheprocessperformanceovertime.Weplantheprocessbaselininginsuchawayastomaximizetheopportunityfor

7、capturingtheaffectofassignablecausevariation.sLTwillrecordthetotalassignablecausevariation.ZLTwillreportthetotallongtermcapability.Inordertoaddressthisvariation,we’llneedtoknowhowthevariousvitalfactorscontributetocausingit.ThiswillbetheobjectiveofAnalyze.9可归属原因的差异这种差异是外来因素影响程序运行的结果。运