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1、RichardL.VanHorn,AlbertB.SchwarzkopfandR.LeonPrice.Copyrightpending,2001.Thesematerialsmaynotbeusedorreproducedwithoutthepermissionoftheauthors.AstudentenrolledattheUniversityofOklahomainMIS4663orMIS5203haspermissiontoprintoutacopyforhis/herownuseonly.C
2、hapter8Revised7-10-02SystemDesignTableofContentsIntroduction.1InputstoSystemDesign.2OutputsforSystemDesign.2Infrastructure3Organization5Data6RelationalSchema.7Metadata.8OtherDataSchema.12Process.12PhysicalDataFlowDiagrams.12ProgramStructureCharts.13Func
3、tionHierarchyDiagrams.14Dialog.16WebPageNavigationMaps.17Action-EventDiagrams.20WebMetadata.21ModuleDesign.21ModuleSpecification.23Pseudo-code.25TypicalSystemDesignRequirements32ProcessDrivenSystems.32DialogDrivenSystems.33DataWarehouseSystems.33Exercis
4、es.348-38IntroductionUpuntilnowithasbeenpossibletobefairlypreciseaboutthedocumentationrequirementsforproblemdefinitionandtheanalysisofsystemrequirements.ThefunctionsthatmostsystemsmustdocanusuallybecapturedbyastandarddatamodellikeanEntityRelationshipDia
5、gramandaprocessmodellikeaDataFlowDiagram.Thepurposeofdesigndocumentationistospecifytoaprogrammerexactlywhattocodewithoutactuallywritingtheprogram.Agoodruleofthumbistoexpectthedesigndocumentationtobemaintenancemanualforaclassmatetouseforthesystem.Itneeds
6、tospecifyhowtheprogramistowork,butbeeasiertofollowthantheactualcode.Thismeansthatthedocumentationdependsonboththesystemandtheenvironmentinwhichitisbuilt.Designdocumentationhastomatchrequirementsoftheprogramtothelanguage.Thetechniqueweusetogeneratedocume
7、ntationismodeling.Amodelisasimplifiedversionofthesystemwewant.Itmustbeeasiertoworkwithbutcapturesomeessentialfeatureofthefinalproduct.Eachparticularmodelweuse–DFD,ERD,RelationalSchema,StructureChart,pseudo-codeorothertechnique–focusesonpartofthesysteman
8、dignoresotherparts.Thedesigndocumentationforthesystemconsistsofasetofmodelsthatcapturethecriticalfeaturesofthesystem.Thecriticalfeatures,andchoiceofmodels,dependonthesystem.Whentheteamselectsthealternativeofbuildingtheproposedsys