北航“软件工程管理”讲义VIP

康一梅kangyimei,SoftwareEngineeringManagement,InformationGathering,TeachingMethod,SoftwareEngineeringtheoriescombinewithcasestudies.,课程介绍,TeachingMethod,项目组成员对项目管理的理解与项目经理的理解同等重要,课程介绍,OurGoals,ProgrammerDesignerProjectManager！ManagerofSoftwareDevelopmentRambulanceswerearrivinglateordoublinguponcalls.Distraughtemergencycallerswerealsoheldinaqueuingsystemwhichfailedtoputthemthroughforupto30minutes.ChrisHumphreys,Nupesdivisionalofficer,saidthatitwashardtoverifyhowmanypeoplemighthavediedbecauseofthedelaysbutitcouldbeasmanyas20.However,theambulanceservicecontradictedclaimsthatone14-year-oldboyhaddiedofanasthmaattachafterwaiting45minutes.Itsaidthatthecallwasdealtwithin28minutes-althoughthePatientsCharterhasatargetof14minutes.Amanof83wasalsosaidtohavediedbeforetheservicerevertedtotheoldsystemat2p.m.onTuesday.Causes:assumedlocationofambulancesknown,memoryleak,operatorsleftoutFrom27/Risks/13.88.html#subj1.1,HumanError,EDBFellesdataASrunsthecomputerservicesofabouthalfofNorwaysbanks.OnThursday2Aug2001,theyapparentlyinstalledabout280disksintheirHitachistorage.Then,insteadofinitializingthenewdisks,theyinitalizedalltheirdisks-therebywipingouttheentirewarehouse.EDBFellesdataitselfdeclinestomakeanystatementsinthecasependingfurthercontactwiththeircustomers,thebanks.Theyareconsideringlawsuits,butifoneoftheirownemployeesmadeausererror,theymayhaveahardtimeofit.,http:/www.digitoday.no/dtno.nsf/pub/dd20010807092448_er_28707255(inNorwegian),ThreatstoHumanLife,Veryfamous(infamous)caseIn1986,twocancerpatientsattheEastTexasCancerCenterinTylerreceivedfatalradiationoverdosesfromtheTherac-25,acomputer-controlledradiation-therapymachine.Therewereseveralerrors,amongthemthefailureoftheprogrammertodetectaracecondition(i.e.,miscoordinationbetweenconcurrenttasks).,Programming/testingErrorAriane5,IttooktheEuropeanSpaceAgency10yearsand$7billiontoproduceAriane5,agiantrocketcapableofhurlingapairofthree-tonsatellitesintoorbitwitheachlaunchandintendedtogiveEuropeoverwhelmingsupremacyinthecommercialspacebusiness.AllittooktoexplodethatrocketlessthanaminuteintoitsmaidenvoyagescatteringfieryrubbleacrossthemangroveswampsofFrenchGuiana,wasasmallcomputerprogramtryingtostuffa64-bitnumberintoa16-bitspace.At39secondsafterlaunch,astherocketreachedanaltitudeoftwoandahalfmiles,aself-destructmechanismfinishedoffAriane5,alongwithitspayloadoffourexpensiveanduninsuredscientificsatellites.Thisdisintegrationhadbegunaninstantbefore,whenthespacecraftswervedoffcourseunderthepressureofthethreepowerfulnozzlesinitsboostersandmainengine.Therocketwasmakinganabruptcoursecorrectionthatwasnotneeded,compensatingforawrongturnthathadnottakenplace.,Ariane5continued,Steeringwascontrolledbytheon-boardcomputer,whichmistakenlythoughttherocketneededacoursechangebecauseofthenumbers,whichinfactwereanerrormessage,comingfromtheinertialguidancesystem.Theguidancesystemhadinfactshutdown36.7secondsafterlaunch,whentheguidancesystemsowncomputertriedtoconvertonepieceofdata-thesidewaysvelocityoftherocket-froma64-bitformattoa16-bitformat=overflowerror.Whentheguidancesystemshutdown,itpassedcontroltoanidentical,redundantunit,whichwastheretoprovidebackupincaseofjustsuchafailure.Guesswhat-thesecondunit(havingthesamesoftware)failedtoo.Inanearlierdesigndecision,theprogrammershaddecidedthatthisparticularvelocityfigurewouldneverbelargeenoughtocausetrouble.Afterall,itneverhadbeenbefore.BUTAriane5wasafasterrocketthanAriane4.Oneextraabsurdity:thecalculationcontainingthebugactuallyservednopurposeoncetherocketwasintheair.Itsonlyfunctionwastoalignthesystembeforelaunch.Soitshouldhavebeenturnedoff.,Whydoessoftwarefail(Charette1989),Terminatedforconvenience/non-performanceofcontract.Completedbutthesystemisnotdeployedasuserscannotorwillnotuseit.Completedbutthesystemdoesnotmeettheoriginallypromisedcost.Completedbutthesystemdoesnotmeettheoriginallypromisedschedule.Completedbutthesystemdoesnotmeettheoriginallypromisedquality.Completedbutthesystemdoesnotmeettheoriginallypromisedcapability.Completedbutthesystemcouldnotbeevolvedinacost-effectivemanner,Whatmakessoftwarespecial?,ThemaindifferencesinsoftwareengineeringcomparedtootherengineeringdisciplinesarelistedBSI,1995.Itisdifficultforacustomertospecifyrequirementscompletely.Itisdifficultforthesuppliertounderstandfullythecustomerneeds.Indefiningandunderstandingrequirements,especiallychangingrequirements,largequantitiesofinformationneedtobecommunicatedandassimilatedcontinuously.Softwareisseeminglyeasytochange.Softwareisprimarilyintangible;muchoftheprocessofcreatingsoftwareisalsointangible,involvingexperience,thoughtandimagination.Itisdifficulttotestsoftwareexhaustively,ASolution-SoftwareEngineering:,Greateremphasisonsystematicdevelopment.Computerassistanceforsoftwaredevelopment(CASE)AconcentrationonfindingouttheusersrequirementsFormal/SemiFormalspecificationoftherequirementsofasystemDemonstrationofearlyversionofasystem(prototyping)Greateremphasesontryingtoensureerrorfreecode,SoftwareEngineering,Definitions:SimpleDefinition:Designing,buildingandmaintaininglargesoftwaresystemsOthers:Softwareengineeringisconcernedwiththetheories,methodsandtoolsfordeveloping,managingandevolvingsoftwareproductsI.SommervilleThepracticalapplicationofscientificknowledgeinthedesignandconstructionofcomputerprogramsandtheassociateddocumentationrequiredtodevelop,operateandmaintainthemB.W.BoehmTheestablishmentanduseofsoundengineeringprinciplesinordertoobtaineconomicallysoftwarethatisreliableandworksefficientlyonrealmachinesF.L.Bauer,WhatisSoftwareEngineering?,Softwareengineeringisthesystematicapproachtothedevelopment,operation,maintenanceandretirementofsoftware.,Thetermsoftwareengineeringisanacknowledgementofthechallengesassociatedwithlarge-scale,high-qualitysoftware.,Cooperationbetweendevelopers,clientsandusers,Sizeandcomplexity,Softwaremustevolveovertime,Asoftwareengineermustusetheprincipleofcomputerscience,engineering,design,management,psychology,sociologyandotherdisciplieswherenecessarytodesignandmanagelargesoftwaresystems,WHATISSOFTWAREENGINEERING?TheIEEEComputerSocietydefinessoftwareengineeringas:(1)Theapplicationofasystematic,disciplined,quantifiableapproachtothedevelopment,operation,andmaintenanceofsoftware;thatis,theapplicationofengineeringtosoftware.(2)Thestudyofapproachesasin(1).,SoftwareEngineering,IntroductiontoSoftwareEngineering,SoftwareEngineering,IntroductiontoSoftwareEngineering,SoftwareEngineering,IntroductiontoSoftwareEngineering,SoftwareEngineering,IntroductiontoSoftwareEngineering,SoftwareEngineering,IntroductiontoSoftwareEngineering,SoftwareEngineering,IntroductiontoSoftwareEngineering,定义科学(物理科学):是一个理性的、按照一定方法理解自然的过程，其主要目标是获得一定的预测能力或解决问题的能力。工程：是利用自然规律创建至少能使一部分人受益的系统。决策：不可更改的资源分配。为一个工程系统如计算机或汽车选择设计参数的过程就是分配资源。设计是一个决策的过程，选择设计参数就是指定决策。系统工程：把工程设计视为决策指定过程的一门学科。,EngineersusesciencetowardspracticalendsSoftwareEngineering=ComputerScience+Engineering,SoftwareEngineeringvsComputerScience,ComputerScience,Engineering,SoftwareEngineering,SoftwareEngineering=ComputerScience+Engineering,ComputerScienceLanguagesAlgorithms/datastructuresMethodsofcomputationFormalmethodsSecurityDatabases/InformationStorageSoftwareparadigms,SoftwareEngineering=ComputerScience+Engineering,EngineeringMethodologiesProcessesProfessionalismEconomics“Doingforadimewhatanyonecandoforadollar”,Teamwork,WorkingwithothersoftwareengineersWorkingwithotherengineers(electrical,mechanical,civil,)WorkingwithmanagersWorkingwithclients,TraditionalSECSRivalry,Challenges,FocusonutilitiesScalabilityMaintainabilityAdaptabilityReusabilityQualityPortabilityEfficiencyUsabilityReliability,TackledwithtechniquessuchasSeparationofconcernsPolicy/mechanismModularisationAbstractionPatterns&reuseTackledusingprocessessuchasReviewTestingDocumentation,DefinitionofProjectoutofControl,软件失控项目就是由于在创建系统所需软件时遭遇到困难，从而导致大大超出可控制范围的项目。,如果所用时间是预计时间的两倍以上或费用超出预算两倍以上的项目为失控项目。软件开发的滑铁卢,软件失控项目是显著未能实现目标和（或）至少超出原定预算30%的项目。KPMG1995,ProjectManagement,IntroductiontoSoftwareProjectManagement,ProjectoutofControl,“野心过大”造成失败，多数失控项目都是或曾经是大型项目。多数失控项目失败原因有多种。可能有、也可能没有起主导作用的原因，但总会有多个问题导致失败。很多失败项目在开发初期被人们赞誉为“有重大进展”，与将要替换掉的系统相比，这些项目具有极大的优势。如果该项目不是被全面展开，人们似乎都看不到有失败的可能。进度超时（89%）比成本超额（62%）更为普遍。首先意识到项目失控的是项目团队（72%），只有19%的项目失控是由高层领导首先意识到的。55%的失控项目没有实行过任何风险管理，而在38%实行了风险管理的项目中，50%在启动之后没有使用风险发现（riskfinding）。技术越来越成为项目失控的原因，而且势头发展迅猛。,ProjectManagement,IntroductiontoSoftwareProjectManagement,ProjectManagement,IntroductiontoSoftwareProjectManagement,TheinvestigationinUSAandUKindicatedthatthefailureof50%out-of-controlled-projectsareduetotechnicalproblems.Technologyisfundamentalityofsoftwareprojects.Projectmanagementistoensurethesuccessfulimplementationofpropertechnicaldesign.,TechnicalProblems,NewTechnicalSolutionsSystemStructureDesignPerformance,IntroductiontoSoftwareProjectManagement,ProjectManagement,坦率地说，微软所面临的挑战之一是它的很多员工还没有遭遇过多少次失败。很多人从未遇到过失败的项目。结果是，人们把成功视为理所当然的事，这是很危险的人们遭遇失败时，将被迫发挥出创造性，不分昼夜地深入探索并苦思冥想。每个公司都需要有过这种经历的人。比尔.盖茨“犯错的重要性”，美国航空杂志,项目团队必须满足“一定会完成项目”的最低层次需求，接着再来考虑有关时间和预算目标百分之十上下的问题。微软项目求生法则,Microsoft,IntroductiontoSoftwareProjectManagement,ProjectManagement,Suggestion,IntroductiontoSoftwareProjectManagement,ProjectManagement,Managementisabudgetitemforsystemdevelopment.Selectordesignyourownmanagementpatternandfinancialplanaccordingtoyourstatusquo.,ClassicMistakes,People挫伤积极性人员素质低对有问题的员工失控英雄主义项目后期加入人员办公环境拥挤嘈杂开发人员与客户发生摩擦不现实的预期缺乏有效的项目支持（高层）缺乏各种角色的齐心协力缺乏用户介入政治高于物质充满想象,IntroductiontoSoftwareProjectManagement,ClassicMistakes,Process过于乐观的计划缺乏足够的风险管理承包人导致的失败缺乏计划在压力下放弃计划在模糊的项目前期浪费时间前期活动不合要求设计低劣缺少质量保证措施缺少管理控制太早或过于频繁集成项目估算时遗漏必要的任务追赶计划卤莽编码,IntroductiontoSoftwareProjectManagement,ClassicMistakes,Product需求镀金功能蔓延开发人员镀金又推又拉的交易研究导向的开发,IntroductiontoSoftwareProjectManagement,ClassicMistakes,Technology银弹综合症过高估计了新技术或方法带来的节省量项目中间切换工具缺乏自动的源代码控制手段,IntroductiontoSoftwareProjectManagement,TheIdealModel,IntroductiontoSoftwareProjectManagement,CapabilityMaturityModel,INITIAL,REPEATABLE,DEFINED,MANAGED,OPTIMIZING,54321,Adhoc,Individual,BasicPM,Similar,StdSWProcess,Quantified&Measured,QuantifiedFeedback,IntroductiontoSoftwareProjectManagement,ProjectManagement,1.ProjectIntegrationManagement,2.ProjectScopeManagement,3.ProjectTimeManagement,4.ProjectCostManagement,5.ProjectQualityManagement,6.ProjectHumanResourceManagement,7.ProjectCommunicationsManagement,8.ProjectRiskManagement,9.ProjectProcurementManagement,IntroductiontoSoftwareProjectManagement,ManagementMaturity,ScopeManagementQualityManagementTimeManagementCostManagementHumanResourceManagementContractor/ProcurementManagementCommunicationsManagementIntegrationManagementRiskManagement,BaselineBuildingaTeamBuildingaProjectBuildingSuccess,IntroductiontoSoftwareProjectManagement,SoftwareProject,GeneralProduct,SystemSoftwareDevelopmentPlatformsCommercialSoftwareEmbeddedSoftware,ApplicationSolution,ServiceProject,ImplementationProject,IntroductiontoSoftwareProjectManagement,Softwaredevelopmentorientedbycustomerrequirements.,SuccessVision,IdentifyStrategicCustomerNeedsUtilizeLeastCostOfferExpectedFunctionsandmoreImplementFastestScheduleEnabl