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1、SystemAnalysisandDesignSystemsanalysisanddesignisasix-phaseproblem-solvingprocedureforexaminingandimprovinganinformationsystem.Wedescribeddifferenttypesofinformationsystemsinthechapter.Nowletusconsider:What,exactly,isasystem?Wecandefineitasacollectionofactivitiesandelementsorganizedt
2、oaccomplishagoal,aninformationsystemisacollectionofhardware,software,people,procedures,anddata.Thisworktogethertoprovideinformationessentialtorunninganorganization.Thisinformationhelpstoproduceaproductorserviceand,forprofit-orientedbusinesses,deriveaprofit.Information---aboutordersre
3、ceived,productsshipped,moneyowed,andsoon---flowsintoanorganizationfromtheoutsideInformation---aboutwhatsupplieshavebeenreceived,whichcustomershavepaidtheirbills,Inordertoavoidconfusion,theseflowsofinformationmustfollowsomesystem.However,fromtimetotime,organizationsneedtochangetheirin
4、formationsystems.Reasonsincludeorganizationalgrowth,mergersacquisitions,newmarketingopportunities,revisionsingovernmentalregulations,andavailabilityofnewtechnology.Systemsanalysisanddesignisasix-phaseproblem-solvingprocedureforexaminingandimprovinganinformationsystem.Thesixphasesmake
5、upthesystemslifecycle.Thephasesareasfollows.Phase1:PreliminaryinvestigationTheinformationproblemsorneedsareidentified.Inthepreliminaryinvestigationphase,theproblemsarebrieflyidentifiedandafewsolutionsaresuggested.Thefirstphaseisapreliminaryinvestigationofaproposedprojecttodetermineth
6、eneedforanewinformationsystem.Thisusuallyisrequestedbyanenduseroramanagerwhowantssomethingdonethatisnotpresentlybeingdone.Phase2：DocumentingSystemsAnalysisThepresentsystemisstudiedindepth.Nowrequirementsarespecified.Inlargerorganizations,thesystemsanalysisstageistypicallydocumentedin
7、areportforhighermanagement.Thesystemsanalysisreportdescribesthecurrentinformationsystem,therequirementsforanewsystem,andapossibledevelopmentschedule.Phase3:systemDesign:AneworalternativeinformationsystemisdesignedInthesystemsdesignphase,aneworalternativeinformationsystemisdesigned.Ph
8、ase3issystem
