外文翻译 - 信息系统开发和数据库开发

0外文原文InformationSystemDevelopmentandDatabaseDevelopmentInmanyorganizations,databasedevelopmentfromthebeginningofenterprisedatamodeling,datamodelingenterprisesdeterminethescopeofthedatabaseandthegeneralcontent.Thisstepusuallyoccursinanorganizationsinformationsystemplanningprocess,itaimstohelporganizationscreateanoveralldatadescriptionorexplanation,andnotthedesignofaspecificdatabase.Aspecificdatabaseforoneormoreinformationsystemsprovidedataandthecorporatedatamodel(whichmayinvolveanumberofdatabases)describedbytheorganizationmaintainingthescopeofthedata.Datamodelingintheenterprise,youreviewofthecurrentsystem,theneedtosupportanalysisofthenatureofthebusinessareas,theneedforfurtherdescriptionoftheabstractdata,andplanningoneormoredatabasedevelopmentproject.Figure1showsPineValleyfurniturecompanysenterprisedatamodelofapart.1.1InformationSystemArchitectureAsshowninfigure1,seniordatamodelisonlygeneralinformationsystemarchitecture(ISA)orapartofanorganizationsinformationsystemblueprint.Intheinformationsystemplanning,youcanbuildanenterprisedatamodelasawholeinformationsystemarchitecturepart.AccordingtoZachman(1987),SowaandZachman(1992)viewsofaninformationsystemarchitectureconsistsofthefollowingsixkeycomponents:Data(Figure1shows,butthereareothermethodsthat).Manipulationofdataprocessing(ofadataflowdiagramcanbeused,withtheobjectmodelmethods,orothersymbolsthat).Networks,whichorganizationsandinorganizationswithitsmaintransmissionofdatabetweenbusinesspartners(itcanconnectthroughthenetworktopologymapandtodemonstrate).Peoplewhodealwiththeimplementationofdataandinformationandisthesourceandreceiver(intheprocessmodelforthedatashowsthatthesenderandthereceiver).Implementationoftheeventsandtimepoints(theycanusestatetransitiondiagramandothermeans.)Thereasonsfortheincidentanddataprocessingrules(oftenintheformoftextdisplay,buttherearealsoanumberofchartsfortheplanningtoolssuchasdecisiontables).1.2InformationEngineering1Informationsystemsplannersinaccordancewiththespecificinformationsystemplanningmethodsdevelopedinformationsystemarchitecture.Informationengineeringisapopularandformalmethods.Informationengineeringisadata-orientedcreationandmaintenanceoftheinformationsystem.Informationengineeringisbecausethedata-oriented,sowhenyoubegintounderstandhowthedatabaseisdefinedbythelogoandwheninformationengineeringaconciseexplanationisveryhelpful.InformationEngineeringfollowtop-downplanningapproach,inwhichspecificinformationsystemsfromawiderangeofinformationneedsintheunderstandingderivedfrom(forexample,weneedaboutcustomers,products,suppliers,salesandprocessingofthedatacenter),ratherthanmergingmanydetailedinformationrequested(orderssuchasascreenorinaccordancewiththeimportationofgeographicalsalessummaryreport).Top-downplanningwillenabledeveloperstoplanmorecomprehensiveinformationsystem,considersystemcomponentsprovideanintegratedapproachtoenhancetheinformationsystemandtherelationshipbetweenthebusinessobjectivesoftheunderstanding,deepentheirunderstandingofinformationsystemsthroughouttheorganizationinunderstandingtheimpact.InformationEngineeringincludesfoursteps:planning,analysis,designandimplementation.Theplanningstageofprojectinformationgeneratedinformationsystemarchitecture,includingenterprisedatamodel.1.3InformationSystemPlanningInformationsystemsplanningobjectiveistoenableITorganizationsandthebusinessstrategycloselyintegrated,suchintegrationfortheinformationsystemsandtechnologytomakethemostoftheinvestmentinterestisveryimportant.Asthetableasadescription,informationengineeringapproachtheplanningstageincludethreesteps,weinthefollow-upofthreesectionstheydiscussed.1.CriticalfactorsdeterminingtheplanningPlanningisthekeyfactorthatorganizationalobjectives,criticalsuccessfactorsandproblemareas.Thesefactorsdeterminethepurposeoftheestablishmentofplanningandenvironmentplanningandinformationsystemslinkedtostrategicbusinessplanning.Table2showsthePineValleyfurniturecompanyskeyplanninganumberofpossiblefactors,thesefactorscontributetotheinformationsystemsmanagerforthenewinformationsystemsanddatabasesclubstopprioritytodealwiththedemand.Forexample,giventheimprecisesalesforecaststhisproblemareas,informationsystemsmanagersintheorganizationmaybestoredinthedatabaseadditionalhistoricalsalesdata,newmarketresearchdataandnewproducttest2data.2.TheplanningorganizationssettargetsOrganizationsplanningtargetsdefinedscopeofbusiness,andbusinessscopewilllimitthesubsequentanalysisandinformationsystemsmaychangeplaces.Fivekeyplanningtargetsasfollows:anizationslocationoftheplaceofbusinessoperations.functionsofthebusinesssupportorganizationshandlingmissionoftherelevantgroup.Unlikebusinessorganizationsfunctionmodules,infactafunctioncanbeassignedtovariousorganizationsmodules(forexample,productdevelopmentfunctionistheproductionandsaleofthecommonresponsibilityoftheMinistry).typesofentitiesmanagedbytheorganizationonthepeople,placesandthingsofthemajortypesofdata.InformationSystemdatasetprocessingsoftwareapplicationsandsupportprocedures.3.TosetupabusinessmodelAcomprehensivebusinessmodelincludingthefunctionsofeachenterprisefunctionaldecompositionmodel,theenterprisedatamodelandthevariousplanningmatrix.Functionaldecompositionisthefunctionoftheorganizationforamoredetaileddecompositionprocess,thefunctionaldecompositionistosimplifytheanalysisoftheissue,distractedandidentifycomponentsandtheuseoftheclassicalapproach.PineValleyfurniturecompanyinordertofunctioninthefunctionaldecompositionexampleinfigure2below.Indealingwithbusinessfunctionsandsupportfunctionsofthefullset,multipledatabases,isessentialtoaspecificdatabasethereforelikelyonlytosupportfunctions(asshowninFigure2)provideasubsetofsupport.Inordertoreducedataredundancyandtomakedatamoremeaningful,hasacomplete,high-levelbusinessviewisveryhelpful.Theuseofspecificenterprisedatamodeltodescribethesymbol.Apartfromthegraphicaldescriptionofthistypeofentity,acompleteenterprisedatamodelshouldalsoincludeadescriptionofeachentitytypedescriptionofbusinessoperationsandasummaryofthatbusinessrules.Businessrulesdeterminethevalidityofthedata.Anenterprisedatamodelincludesnotonlythetypesofentities,includingthelinkbetweenthedataentities,aswellasvariousotherobjectsplanninglinks.Showedthatthelinkagebetweenplanningtargetsacommonformofmatrix.Becauseofplanningmatrixneednotbeexplicitmodelingdatabasecanbeclearlydescribedbusinessneeds,planningmatrixis3animportantfunction.Regularplanningmatrixderivedfromtheoperationalrules,itwillhelpsocialdevelopmentactivitiesthattopprioritywillbesortinganddevelopmentactivitiesunderthetop-downviewthroughanenterprise-wideapproachforthedevelopmentoftheseactivities.Therearemanytypesofplanningmatrixisavailable,theircommonalitiesare:locations-featuresshowbusinessfunctioninwhichtheimplementationofoperationallocations.unit-functionswhichshowedthatbusinessfunctionorbusinessunitresponsibleforimplementation.InformationSystem-dataentitiestoexplainhoweachinformationsysteminteractwitheachdataentity(forexample,whetherornoteachsystemineachentityhavethedatatocreate,retrieve,updateanddelete).supportfunctions-dataineachfunctionalentitiesinthedatasetfortheacquisition,use,updateanddelete.InformationSystem-targetindicationforeachinformationsystemtosupportbusinessobjectives.Figure3illustrateapossiblefunctions-dataentitiesmatrix.Suchamatrixcanbeusedforavarietyofpurposes,includingthefollowingthreeobjectives:1)identifygapsinthedataentitiestoindicatethetypesofentitiesnotuseanyfunctionorfunctionswhichdonotuseanyentity.2)foundthatthelossofeachfunctionalentitiesinvolvedintheinspectionstaffthroughthematrixtoidentifyanypossiblelossoftheentity.3)Thedistinctionbetweendevelopmentactivitiesiftheprioritytothetopofasystemdevelopmentfunctionforahigh-priority(probablybecauseitimportantorganizationalobjectivesrelated),thenthisareausedbyentitiesinthedevelopmentofthedatabasehasahighpriority.Hoffer,GeorgeandValacich(2002)aretheworksofthematrixonhowtousetheplanningandcompletionoftheInformationEngineeringTheplanningsystemmorecompletedescription.2databasedevelopmentprocessBasedoninformationengineeringinformationsystemsplanningdatabaseisasourceofdevelopmentprojects.Thesenewdatabasedevelopmentprojectsisusuallyinordertomeetthestrategicneedsoforganizations,suchasimprovingcustomersupport,improveproductandinventorymanagement,oramoreaccuratesalesforecast.However,manymoredatabase4developmentprojectisthebottom-upapproachemerging,suchasinformationsystemuserneedsspecificinformationtocompletetheirwork,thusbeginningaprojectrequest,andasotherinformationsystemsexpertsfoundthatorganizationsneedtoimprovedatamanagementandbeginnewprojects.Bottom-upeveninthecircumstances,tosetupanenterprisedatamodelisalsonecessarytounderstandtheexistingdatabasecanprovidethenecessarydata,otherwise,thenewdatabase,dataentitiesandattributescanbeaddedtothecurrentdataresourcestotheorganization.Boththestrategicneedsoroperationalinformationneedsofeachdatabasedevelopmentprojectsnormallyconcentratedinadatabase.Someprojectsonlyconcentratedinthedatabasedefinition,designandimplementationofadatabase,asafollow-uptothebasisofthedevelopmentofinformationsystems.However,inmostcases,thedatabaseandassociatedinformationprocessingfunctionasacompleteinformationsystemsdevelopmentprojectwaspartofthedevelopment.2.1SystemDevelopmentLifeCycleGuidemanagementinformationsystemdevelopmentprojectsisthetraditionalprocessofsystemdevelopmentlifecycle(SDLC).SystemdevelopmentlifecycleisanorganizationofthedatabasedesignersandprogrammersinformationsystemcomposedofthePanelofExpertsdetaileddescription,development,maintenanceandreplacementoftheentireinformationsystemsteps.ThisprocessisbecauseWaterfallthanforeverystepintotheadjacentthenextstep,thatis,theinformationsystemisaspecificationdevelopedbyapieceofland,everypieceoftheoutputisunderaninput.Howevershowninthefigure,thesestepsarenotpurelylinear,eachofthestepsoverlapintime(andthuscanmanageparallelsteps),butwhentheneedtoreconsiderpreviousdecisions,butalsotorollbacksomestepsahead.(Andthereforewatercanbeputbackinthewaterfall!)Figure4onthesystemdevelopmentlifecycleandthepurposeofeachstageoftheproductcanbedeliveredconcisenotes.Thesystemdevelopmentlifecycleincludingeachstageanddatabasedevelopment-relatedactivities,therefore,thequestionofdatabasemanagementsystemsthroughouttheentiredevelopmentprocess.InFigure5werepeatofthesystemdevelopmentlifecyclestageoftheseven,andoutlinesthecommondatabaseateachstageofdevelopmentactivities.Pleasenotethatthesystemsdevelopmentlifecyclestagesanddatabasedevelopmentsteps一一对应existsbetweentherelationshipbetweentheconceptofmodelingdatainbothsystemsdevelopmentlifecyclestagesbetween.EnterpriseModeling5Databasedevelopmentprocessfromtheenterprisemodeling(systemdevelopmentlifecyclestageoftheprojectfeasibilitystudies,andtochooseapart),Organizationssetthescopeandgeneraldatabasecontent.Enterprisemodelingininformationsystemsplanningandotheractivities,theseactivitiesdeterminewhichpartofinformationsystemsneedtochangeandstrengthentheentireorganizationandoutlinesthescopeofdata.Inthisstep,checkthecurrentdatabaseandinformationsystems,developmentoftheprojectasthemainareasofthenatureofthebusiness,withaverygeneraldescriptionofeachterminthedevelopmentofinformationsystemswhenneededdata.Eachitemonlywhenitachievedtheexpectedgoalsoforganizationscanbewhenthenextstep.ConceptualDataModelingOnehasalreadybegunontheInformationSystemproject,theconceptofdatamodelingphaseoftheinformationsystemsneedsofallthedata.Itisdividedintotwostages.First,itbegantheprojectintheplanningstageandtheestablishmentofaplansimilartoFigure1.Atthesametimeoutliningtheestablishmentofotherdocumentstotheexistingdatabasewithoutconsideringthecircumstancesspecificdevelopmentprojectsinthescopeoftherequireddata.Thiscategoryonlyincludeshigh-leveldata(entities),andmaincontact.Theninthesystemdevelopmentlife-cycleanalysisstagemusthaveamanagementinformationsystemsettheentireorganizationDetailsofthedatamodeldefinitionofalldataattributes,listingalldatatypesthatalldatainter-entitybusinesslinkages,definingdescriptionofthefulldataintegrityrules.Intheanalysisphase,butalsotheconceptofinspectiondatamodel(alsocalledtheconceptbehindthemodel)andthegoalofinformationsystemsusedtoexplainotheraspectsofthemodelofconsistencycategories,suchasprocessingsteps,rulesanddataprocessingtimeoftiming.However,eveniftheconceptissuchdetaileddatamodelisonlypreliminary,becausefollow-upinformationsystemlifecycleactivitiesinthedesignofservices,statements,displayandinquiriesmayfindthatmissingelementormistakes.Therefore,theconceptofdataoftensaidthatmodelingisatop-downmanner,itsareasofoperationfromthegeneralunderstandingofthedriver,ratherthanthespecificinformationprocessingactivitiesbythedriver.3.LogicalDatabaseDesignLogicaldatabasedesignfromtwoperspectivesdatabasedevelopment.First,theconceptofdatamodeltransformintorelationaldatabasetheorybasedonthecriteriathatmeans-between.Then,asthedesignofinformationsystems,everycomputerprocedures(includingproceduresfortheinputandoutputformat),databasesupportservices,statements,and6inquiriesrevealedthatadetailedexamination.Inthisso-calledBottom-upanalysis,accurateverificationoftheneedtomaintainthedatabaseandthedataineachaffairs,statementsandsoontheneedsofthoseinthenatureofthedata.Foreachseparatestatements,services,andsoontheanalysismusttakeintoaccountaspecific,limitedbutcompletedatabaseview.Whenstatements,services,andotheranalysismightbenecessarytochangetheconceptofdatamodel.Especiallyinlarge-scaleprojects,thedifferentanalyticalsystemsdevelopmentstaffandtheteamcanworkindependentlyindifferentproceduresorinacentralized,thedetailsoftheirworkuntilallthelogicdesignstagemaybedisplayed.Inthesecircumstances,logicdatabasedesignstagemustbetheoriginalconceptofdatamodelanduserviewtheseindependentormergedintoacomprehensivedesign.Inlogicdesigninformationsystemsalsoidentifyadditionalinformationprocessingneedsofthesenewdemandsatthistimemustbeintegratedintothelogicofearlieridentifiedinthedatabasedesign.Logicaldatabasedesignisbasedonthefinalstepfortheformationofgooddataspecificationsanddeterminetherules,thecombination,thedataafterconsultationspecificationsorconvertedintobasicatomicelement.Mostoftodaysdatabase,theserulesfromtherelationaldatabasetheoryandtheprocessknownasstandardization.Thisstepistheresultofmanagementofthesedatahavenotcitedanydatabasemanagementsystemforacompletedescriptionofthedatabasemap.Logicaldatabasedesigncompleted,webegantoidentifyindetailthelogicofthecomputerprogramandmaintenance,thereportcontentsofthedatabaseforinquiries.4.PhysicaldatabasedesignanddefinitionPhysicaldatabasedesignanddefinitionphasedecisionscomputermemory(usuallydisk)databaseintheorganization,definitionofAccordingtothelibrarymanagementsystemforphysicalstructure,theproceduresoutlinedprocessingservices,producethedesiredmanagementinformationanddecisionsupportstatements.Theobjectiveofthisstageistodesignaneffectiveandsafemanagementofalldata-processingdatabase,thephysicaldatabasedesigntocloselyintegratetheinformationsystemsofotherphysicalaspectsofthedesign,includingprocedures,computerhardware,operatingsystemsanddatacommunicationsnetworks.5.DatabaseImplementationThedatabasepreparedbytherealizationstage,testingandinstallationproceduresforhandlingdatabases.Designerscanusethestandardprogramminglanguage(suchasCOBOL,7CorVisualBasic),thededicateddatabaseprocessinglanguages(suchasSQL),ortheprocessofthenon-exclusivelanguageprogramminginordertoproduceastatementofthefixedformat,theresultwillbedisplayed,andmayalsoincludecharts.Inachievingstage,butalsothecompletionofallthedatabasefiles,trainingusersforinformationsystems(database)usersetupprogram.Thefinalstepistouseexistingsourcesofinformation(documentslegacyapplicationsanddatabasesandnowneedsnewdata)loadingdata.Loadingdataisoftenthefirststepindatafromexistingfilesanddatabasestoanintermediateformat(suchasbinaryortextfiles)andthentoturnintermediateloadingdatatoanewdatabase.Finally,runningdatabasesandrelatedapplicationsfortheactualusermaintenanceandretrievalofdata.Inoperation,theregularbackupdatabaseandthedatabasewhendamagedoraffectedresumedatabase.6.DatabasemaintenanceDuringthedatabaseintheprogressivedevelopmentofdatabasemaintenance.Inthisstep,inordertomeetchangingbusinessconditions,inordertocorrecttheerroneousdatabasedesign,databaseapplicationsorprocessingspeedincrease,deleteorchangethestructureofthedatabase.Whenaprocedureorfailureofthecomputerdatabaseaffectordamagethedatabasemayalsobereconstruction.Thisstepusuallyisthelongestinthedatabasedevelopmentprocessstep,asitcontinuedtodatabasesandrelatedapplicationsthroughoutthelifecycle,thedevelopmentofeachdatabasecanbeseenasabriefdatabasedevelopmentprocessanddatamodelingconceptsarise,logicalandphysicaldatabasedesignanddatabasetoachievedealingwiththechanges.2.2InformationSystemdevelopedbyothermeansSystemDevelopmentLifeCycleminorchangesinlaworitsvariantoftheoftenusedtoguideinformationsystemsanddatabasedevelopment.InformationSystemisalife-cyclemethodology,itishighlystructuredapproach,whichincludesmanychecksandbalancestoensurethateverystepofproduceaccurateresults,andneworalternativeinformationsystemanditmustcommunicationsordatadefinitionsconsistentexistingsystemneedsconsistency.Systemdevelopmentlifecyclebecauseoftheregularneedtohaveaworkingsystemforalongtimebeencriticizedbecauseonlyworkinthesystemuntiltheendofthewholeprocessgenerated.Moreandmoreorganizationsnowuserapidapplicationdevelopmentmethod,itisaincludesanalysis,designandimplementationofstepstorepeattherapiditerativeprocessuntilconvergencetousersthesystemsofar.RapidApplicationDevelopmentActrequiredthedatabasehasbeeninexistence,andenhancesystemismainlytotheapplicationofdata8retrievalapplication,butnottothosewhogenerateandmodifydatabaseapplications.Themostwidelyusedmethodofrapidapplicationdevelopmentisoneoftheprototype.Theprototypesystemisamethodofiterativedevelopmentprocess,analystsandusersthroughcloseco-operation,continuingtorevisethesystemwilleventuallyconvertalltheneedsofaworkingsystem.Figure6showsprototypeoftheprocess.Inthisdiagramwecontainsnotes,brieflydescribeseachstageoftheprototypeofthedatabasedevelopmentactivities.Normally