软件工程要点第二章

第二章过程和生命周期建 ModelingtheProcessandSoftwareWhatisSoftwareWhatisProcessASeriesofstepsinvolvingactivities,constraints,andresourcesthatproduceanintendedoutputofsomeAprocessusuallyinvolvesasetoftoolsandProcessTheprocessprescribesallmajorprocessProcessusesresources,subjecttosetof占用资源、服从于一组约束(suchasComposedofsubprocesses,withhierarchyorEachactivityhasentryandexitActivitiesareorganizedinasequence,sotimingisHasasetofguidingprinciplesthatexinthegoalsofeachconstraintsorcontrolsmayapplytoanactivity,resourceorLifeWhentheprocessinvolvesthebuildingofsomeproduct,wesometimesrefertotheprocessasalifeThesoftwaredevelopmentprocessissometimescalledthesoftwarelifeProcessesareTheyimposeconsistencyandstructureonasetofTheprocessstructureguidesouractionsbyallowingustoexamine,understand,control,andimprovetheactivitiesthatcomprisetheprocess.Enablingustocaptureourexperiencesandpassthemalongto*新的国际标准定义的软件生存过程（1995ISO/IEC12207） 文配质验程确程联审程问管基 softwareprocessmodelsWhysoftwareprocessSomemodelsareprescriptionsforthewaysoftwaredevelopmentshouldprogress,andothersaredescriptionsofthewaysoftwaredevelopmentisdoneinactuality.Writesdownadescriptionofdevelopmentprocess,formsacommonunderstandingoftheactivities,resources,andconstraintsinvolvedinsoftwaredevelopment.Helpsthedevelopmentteamfindinconsistencies,redundancies,andomissionsintheprocessandinitsconstituentparts.Themodelreflectsthegoalsofdevelopment,suchasbuildinghigh-qualitysoftware,findingfaultsearlyindevelopment,andmeetingrequiredbudgetandscheduleconstraints.EveryprocessshouldbetailoredforthespecialsituationinwhichitwillbeUnitUnit&OperationCharactersofWaterfallOnedevelopmentstageshouldbecompletedbeforethenextIncludestagesofrequirements ysis,systemdesign,programdesign,coding,unit&integrationtesting,acceptancetesting,operation&maintenanceStepsdon’tgoesMeritsofWaterfallHasbeenusedtoprescribesoftwaredevelopmentactivitiesinavarietyofIsveryusefulinheldeveloperslayoutwhattheyneedtoEasytoexintocustomerswhoarenotfamiliarwithsoftwareItmakesexplicitwhichintermediateproductsarenecessaryinordertobeginthenextMorecomplexmodelsarereallyjustembellishmentsoftheSoftwaredevelopmentprocessinShortageofWaterfallDoesnotreflectthewaycodeisreallydeveloped,softwareisusuallydevelopedwithagreatdealof ThemodelimposesaprojectmanagementstructureonsystemFailtotreatsoftwareasaproblem-solvingThemodelwasderivedfromthehardwareEnhanceofWaterfallUnit&gration Unit&Inte-Prototy原型化模

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(sometimes(sometimesinformalAPrototypeisapartiallydevelopedproductthatenablescustomersanddeveloperstoexaminesomeaspectoftheproposedsystemanddecideifitissuitableorappropriateforthefinishedproduct.Operationalspecification Operationalinformal

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DeliveredUsingautomatedsupport,thetransformationalprocessappliesaseriesoftransformationstochangeaspecificationintoadeliverablesystem.Phased incrementsandi 阶段开发：增量和迭代模BuildReleaseBuildReleaseBuildReleaseBuildReleaseUseReleaseUseReleaseUseReleaseProductionIncremental tive tiveIncrementalthesystemasspecifiedintherequirements sispartitionedintosubsystemsbyfunctionality.Thereleasesaredefinedbybeginningwithon