Session Five – Using Outputs and Managing Projects第五课-使用产出和管理项目

SessionFive–UsingOutputsandManagingProjectsMRPsoftwaregeneratesexceptionreportsthatsuggestactionsplannerneedtotaketomaintainvalidpriorities.Suchactionsincludethefollowing:>Releaseplannedorders>Expediteorder>Delayanorderorscheduledreceipt>CancelaplannedorderorscheduledreceiptPegging>Single-LevelpeggingallowstheMRPusertotracethegrossrequirementforacomponenttoitsparentonlevelup.*Ifthereisanimbalancebetweensupplyanddemand,itisbesttogouponlyonelevelusingsingle-levelpeggingtoresolvetheissue.>Fullpeggingallowstheplannerstracesdemandforacomponenttothelevel0orend-itemsources.Where-usedList>Peggingreportsidentifyparentitemsthatcurrentlyhavegrossrequirementsforagivencomponents.>Incontrast,where-usedlistsprovideinformationoneveryparentitemthatcallsforagivencomponent.*Designengineersusethewhere-usedliststodeterminewhichandhowparentitemswillbeaffectedbyacomponentchange.FirmedPlannedOrders>FPOisneededtopreventMRPlogicfromchangingquantitiesand/ortimes.>MRPsoftwarecannotaltertheduedate,releasedate,orquantityofanorderthathasafirmdesignation.AdvantagesoftheWhat-ifAnalysisandSimulation>Onceadesiredresultisachieved,itcanbecopiedovertothelivesystemandbecometheactualmaterialschedule.>Plannerscanevaluatevariousalternatives.>Plannerscantestprocessimprovementsandmanagerisks.RevisionofPlanningParameters>LeadtimeReduction>>Reasons:->reduceWIPandon-handinventories->shortenplanninghorizonsandlessendependenceonforecasts>>Keycomponents:->Queue*Thelongestleadtimecomponent,thetimespentwaitingforanitemorbatchtobeprocessed->Setup*Setupisthetimebetweentheproductionofthelastgoodpieceinonerunandofthefirstgoodpieceinthenextrun.->Run->Wait->Move>Lotsize*Lotsizingisatrade-offbetweenthecostoforderingandthecostofcarryinginventory.>SafetystockandSafetyleadtime*Safetyleadtime,anotherinventorybufferinMRP,involvesestablishingaplannedorderreceiptdatethatisearlierthenwhenanitemisreallyneededandplannedorderreleasesdatethatisoffsetbythenormalleadtime.>Scrapfactor*Plannedorderrelease=>KanbanquantityandCycletime*KanbanquantityandCycletimeareparametersrelatedtomaterialplanninginalean/JITenvironment.(takttimeissignificant)>>KanbanquantityreferstothelotsizespecifiedontheKanbancard.>>Cycletimeisthetimebetweenthecompletionsoftwodiscreteunitsofproduction.>IntegrationofLean/JITandERP/MRP>>Pullvs.PushsystemsInalean/JITsystem,productionistriggeredbyapullcreatedbycustomerdemandanddemandformaterialsfromdownstreamworkstationsontheshopfloor.Incontrast,inanMRPsystemenvironment,materialsarepushedtoandthroughworkcentersontheshopfloorasaresultofdemandfromforecasts,actualordersforenditems,andderiveddemandforcomponents.>>Advantagesanddisadvantagesoflean/JIT->Lean/JIT’sgreatcontributionisitsabilitytoreduceleadtime,improvequality,andminimizeinventory.Materialsflowquicklyandsmoothlythroughtheproductionprocess.->Lean/JIT’sweaknessisthatkanbanpullsystemsworkbestwhenproductsarenotcomplexanddemandisstableandcontinuous.Thegeneralruleisthatkanban-basedreplenishmentworksbestifthecoefficientofdemandvariation(standarddeviationdividedbyaverageusage)doesnotexceed30percent.

>ProjectmanagementTheuseofskillsandknowledgeincoordinatingtheorganizing,planning,scheduling,directing,controlling,monitoring,andevaluationofprescribedactivitiestoensurethatthestatedobjectivesofaproject,manufacturedgood,orserviceareachieved.>ProjectPlanning>>Keyelements->Statementofwork->Workbreakdownstructure->Projectschedule*Themostcommonprojectschedulingmethodsare:Criticalpathmethod(CPM)-Anetworkplanningtechniquefortheanalysisofaproject’scompletiontimeusedforplanningandcontrollingtheactivitiesinaproject.Byshowingeachoftheseactivitiesandtheirassociatedtimes,thecriticalpath,whichidentifiesthoseelementsthatactuallyconstrainthetotaltimefortheproject,canbedetermined.**CPMismostappropriateforactivitiesthatarewelldefinedand/oraresimilartoactivitiesthathavebeenperformedbefore.Programevaluationandreviewtechnique(PERT)-PERTisbasedonprobabilistictimeestimates,whichderivefromstatisticalmethodsthatdeterminethedurationofanactivity.Threetimeestimatesaremade:O=OptimisticML=MostLikelyP=PessimisticExpectedtime=(O+4ML+P)/6**Whenactivitiesarenotwelldefined,thereisnosimilarexperience,orconfidenceintheestimatesoftaskdurationislow,PERTcanbeused.Ganttcharting-Foreachactivity,thereistypicallyonehorizontalbarthatrepresentsthescheduleforthatactivity.Asecondhorizontalbarrepresentsactualprogressonactivitiesthathavebeenstarted.**TheGanttchartcanbeusedforschedulingrelativelysimpleprojects.Oneofitsdrawbacksisthatitdoesn’texplicitlyshowtherelationshipsbetweenactivities.**PERTandCPMarenetworkschedulingmethodsthathaveseveraladvantagesoverGanttcharting,includingtheabilitytodeterminethecriticalpath(thelongestpathfrombeginningtoendoftheproject),identifyingnoncriticalactivities,andvisualizethesequentialprocessrequiredtocompletetheproject.->Responsibilitymatrix->Resourcerequirements(ConstrainedResourceScheduling)-Therearetwoapproachestoschedulingconstrainedresources:Heuristicmethod:Employsgeneralrulesthathaveworkedwellinsimilarsituations.Optimizationmethod:Optimizationseeksthebestsolution,typicallythroughmathematicalprogrammingandenumeration.Itisbestusedforlarge,complexprojects.*CriticalChainMethod-…anetworkplanningtechniquefortheanalysisofaproject’scompletiontimeusedforplanningandcontrollingprojectactivities.Thecriticalchain,whichdeterminesprojectduration,isbasedontechnologicalandresourceconstraints.*CPMandPERTmethodsofprojectschedulingassumesthattherequiredresourcewillbeavailablewhenneeded.Thecriticalchainmethodhasbeeneffectiveinplanningandcontrollingprojectswithlimitresources.->Budget*Twotypesofcostestimates:Preliminarycostestimateisusedtosupportdecisionsontheviabilityofaproject.Finalcostestimatesareusedtosupportprojectplanningandimplementation.*KeycostcomponentsofthebudgetLabor(salary/wages,benefitscosts,training,overhead)Materials(freight/shippingcharges,taxes,storageandhandlingcharges)Equipment(operatingcosts,methodof