Chapter12 Information System Development

Discovering Computers 2011

Living in a Digital World

Computers 2011

Objectives OverviewObjectivesOverview

Discusstheimportanceofproject managementDefinesystemdevelopment

andlistthesystemdevelopmentphases

Identifytheguidelinesforsystemdevelopment

projectmanagement,feasibilityassessment,

documentation,anddataandinformationgatheringg g

techniques

Explaintheactivitiesperformedintheplanning

phase

Discussthepurposeoftheactivitiesperformedinthe

analysis phase

Describethevarioustoolsusedinprocessmodelingphase analysisphase

DiscoveringComputers2011:LivinginaDigitalWorldChapter12

2SeePage619forDetailedObjectives

Objectives OverviewObjectivesOverview

D ib h i E l i h i i i Recognize the developDescribethevarioustoolsusedinobject

modeling

Explaintheactivitiesperformedinthedesignphase

Recognizethedevelopprogramsactivityis

partofsystemdevelopmentdevelopment

Discuss the purpose ofDiscusstheactivitiesperformedinthe

implementation phase

Discussthepurposeoftheactivities

performedintheoperation support andimplementationphase operation,support,and

securityphase


3SeePage619forDetailedObjectives

What is System Development?WhatisSystemDevelopment?

Systemdevelopment isasetofactivitiesused to build an information systemusedtobuildaninformationsystem

Aninformation

Asystem isasetofcomponents that

system(IS)isacollectionof

hardware software

Systemdevelopmentactivitiesaregroupedinto phases and iscomponentsthat

interacttoachieveacommongoal

hardware,software,data,people,and

proceduresthatwork

intophases,andiscalledthesystemdevelopmentlife

togethertoproducequalityinformation

cycle (SDLC)


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5Pages620 621Figure121


Systemdevelopmentshouldfollowthreegeneralguidelines:g

GroupactivitiesortasksintophasesGroupactivitiesortasksintophasesp pp p

Involve usersInvolve usersInvolveusersInvolveusers

f d df d dDefinestandardsDefinestandards


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Systemdevelopmentshouldinvolverepresentativesfromeachdepartmentinwhichtheproposedsystemwillbeused


7Page622Figure122


Projectmanagement istheprocessofplanning,scheduling,andthencontrollingtheactivitiesduringsystemdevelopment

Toplanandscheduleaprojectefficiently,theprojectleaderidentifies:

Required Time estimatesProjectscope RequiredactivitiesTimeestimatesforeachactivity

Costestimatesfor each activity

Orderofactivities

Activitiesthatcantakeplaceath


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foreachactivity activities thesametime


Apopulartoolused to planusedtoplanandschedulethetime

relationshipsamongprojectactivitiesisaGanttchart

Click to view Web Link,click Chapter 12, Click Web Link from left navigation


9Page623Figure123a

Link from left navigation, then click Gantt Charts below Chapter 12


APERTchartalsocanbeusedfor

planningandscheduling timeschedulingtime



10Page624Figure123b

Link from left navigation, then click PERT Charts below Chapter 12


Feasibility isameasureofhowsuitablethedevelopmentofasystemwillbetothep yorganization

Operationalfeasibility

Schedulefeasibility

Technicalfeasibility

Economicfeasibility


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Documentation isthecollectionandsummarizationofdataandinformation Aprojectnotebookcontainsalldocumentationforasingle projectsingleproject

UsersandITprofessionalsrefertoexistingd i h ki i h d dif idocumentationwhenworkingwithandmodifyingcurrentsystems


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Duringsystemdevelopment,membersoftheprojectteamgatherdataandinformationusingseveraltechniques

Reviewdocumentation Observe Survey

I i JAD S i R hInterview JADSessions Research



WhoInitiatesaSysteml j ?DevelopmentProject?

Ausermayrequestanewormodifiedsystem

Organizationsmaywanttoimprovehardware,software,orothertechnology

Situationsbeyondanorganizationscontrolmightrequireachange

Managementmightmandateachange

Ausermayrequestanewormodifiedinformationsystemusingarequestfor system services or a project requestforsystemservicesoraprojectrequest


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WhoInitiatesaSysteml j ?DevelopmentProject?


15Page627Figure125

Planning PhasePlanningPhase

Theplanningphase foraprojectbeginswhenthesteeringcommitteereceivesaprojectrequestg p j q

Fourmajoractivitiesareperformed:

Reviewandapprovethe

projectrequests

Reviewandapprovethe

projectrequests

PrioritizetheprojectrequestsPrioritizethe

projectrequestsAllocateresourcesAllocateresources

Formaprojectdevelopment

team

Formaprojectdevelopment

team


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Analysis PhaseAnalysisPhase

Theanalysisphase consistsoftwomajoractivities:

Conductapreliminaryinvestigation

Performdetailedanalysisinvestigation

Determinesanddefines the exact

Determinesanddefines the exact

analysis

Studyhowthecurrentsystem works

Studyhowthecurrentsystem worksdefinestheexact

natureoftheproblemorimprovement

definestheexactnatureoftheproblemorimprovement

systemworks Determinetheuserswants, needs, and

systemworks Determinetheuserswants, needs, andp

Interviewtheuserwhosubmittedtherequest

p Interviewtheuserwhosubmittedtherequest

wants,needs,andrequirements

Recommendasolution

wants,needs,andrequirements

Recommendasolution


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Link from left navigation, then click Feasibility Study below Chapter 12


Processmodeling (structuredanalysisanddesign)isananalysisanddesigntechniquethatdescribesprocessesthattransforminputsintooutputs

EntityEntityrelationshipdiagrams

Dataflowdiagrams

ProjectdictionaryClick to view Web Link,click Chapter 12, Click Web

Link from left navigation


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Link from left navigation, then click Process Modeling below Chapter 12


Anentityrelationshipdiagram (ERD)isatoolthatgraphicallyshowstheconnectionsamongentitiesinasystem

Entitiesareobjectsinthesystemthathavedata


20Page632Figure127


Adataflowdiagram(DFD)isatoolthatgraphicallyshowstheflowofdatainasystem Dataflows Processes Datastores Sources


21Page632Figure128


Theprojectdictionary containsallthedocumentationanddeliverablesofaprojectp j

StructuredEnglishisastyle of writing thatstyleofwritingthatdescribesthestepsinaprocess


22Page633Figure129


Adecisiontable isatablethatlistsavarietyofconditionsyandtheactionsthatcorrespondtoeachcondition

Adecisiontreealsoshowsconditionsandactions,butit,showsthemgraphically


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Decisiontable Decisiontree


24Page633Figures1210 1211


Thedatadictionary storesthedataitemsname,description,andotherdetailsabouteachdatapitem


25Page634Figure1212


Objectmodeling combinesthedatawiththeprocessesthatactonthatdataintoasingleunit,calledanobject

UML (UnifiedModelingLanguage)hasbeenadoptedasastandardnotationforobjectmodelinganddevelopment UMLincludes13differentdiagrams Twodiagramsinclude:g

Use caseUsecasediagram ClassdiagramClick to view Web Link,

click Chapter 12, Click Web Link from left navigation


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Link from left navigation, then click UML below Chapter 12


Ausecasediagramgraphicallyshowshowactors(users)interactwiththeinformationsystem

Diagramsareconsideredeasytounderstand


27Page634Figure1213


A l di Aclassdiagramgraphicallyshowsclasses and subclassesclassesandsubclassesinasystem

Each class can have one Eachclasscanhaveoneormoresubclasses

Subclasses use Subclassesuseinheritancetoinheritmethods and attributesmethodsandattributesofhigherlevels


28Page635Figure1214


Thesystemproposalassessesthefeasibilityofeachalternativesolution

Thesteeringcommitteediscussesthesystemproposal and decides which alternative to pursueproposalanddecideswhichalternativetopursue

Packagedsoftware

Customsoftware Outsourcing



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Link from left navigation, then click Vertical Market Software below Chapter 12

Design PhaseDesignPhase

Thedesignphase consistsoftwomajoractivities

AcquirehardwareDevelopallofthedetailsofthenew

andsoftware ormodifiedinformationsystem


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Toacquirethenecessaryhardwareandsoftware:

Useresearch

Solicitvendorproposals Varioustechniques

Makeadecision

techniquessuchasezines RFQ,RFP,orRFIis

senttopotentialvendorsorVARs

qareusedtodeterminethebestproposal

Systemsanalystmakesrecommendationtosteering committee

Identifytechnicalspecifications

Testandevaluatevendorproposals

steeringcommittee



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Link from left navigation, then click E-Zines below Chapter 12


Thenextstepistodevelopdetaileddesignspecificationsp Sometimescalledaphysicaldesign

Databasedesign

Inputandoutputdesign

Programdesigndesign


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Systemsanalyststypicallydeveloptwotypesofdesignsforeachinputandoutputg p p

Mockup Layoutchart


33Page641Figures1218 1219


Aprototype (proofofconcept)isaworkingmodeloftheproposedsystemp p y PrototypeshaveinadequateormissingdocumentationUsers tend to embrace the prototype as a final system Userstendtoembracetheprototypeasafinalsystem

Shouldnoteliminateorreplaceactivities


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Computeraidedsoftwareengineering(CASE)toolsaredesignedtosupportoneormoreg ppactivitiesofsystemdevelopment

CASE tools sometimes contain the following tools: CASEtoolssometimescontainthefollowingtools:

Project hProjectrepository Graphics Prototyping

Qualityassurance

Codegenerator Housekeeping



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gLink from left navigation, then click CASE Toolsbelow Chapter 12



36Page642Figure1220


Manypeopleshouldreviewthedetaileddesignspecificationsp

Aninspectionisaformalreviewofanysystemdevelopment deliverabledevelopmentdeliverable Ateamexaminesthedeliverablestoidentifyerrors


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Implementation PhaseImplementationPhase

Thepurposeoftheimplementationphase istoconstructthenewormodifiedsystemandthenydeliverit

Install andInstall and Convert toConvert toDevelopprogramsDevelopprograms

Installandtestthenew

system

Installandtestthenew

systemTrainusersTrainusers

Converttothenewsystem

Converttothenewsystem


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Theprogramdevelopmentlifecyclefollowsthesesteps: Analyze the requirementsp 1 Analyzetherequirements

2 Designthesolution2 g

3 Validatethedesign

4 Implementthedesign

T t th l ti5 Testthesolution

6 Documentthesolution


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6


Varioustestsshouldbeperformedonthenewsystemy

Unittest Systemstest IntegrationtestAcceptance

test

Verifiesthateach

Verifiesthateach

y

Verifiesthatall programs

Verifiesthatall programs

test

Verifiesthatan

Verifiesthatan

test

Checksthenew system

Checksthenew systemeach

individualprogramorobject works

eachindividualprogramorobject works

allprogramsinanapplicationwork

allprogramsinanapplicationwork

anapplicationworkswithother

anapplicationworkswithother

newsystemtoensurethatitworkswith actual

newsystemtoensurethatitworkswith actualobjectworks

byitselfobjectworksbyitself

worktogetherproperly

worktogetherproperly

otherapplicationsotherapplications

withactualdatawithactualdata


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Training involvesshowingusersexactlyhowtheywillusethenewhardwareandsoftwareinthesystem Oneonone sessions Oneononesessions Classroomstylelectures Webbasedtraining


41Page644Figure1221


Oneormoreoffourconversionstrategiescanbeusedtochangefromtheoldsystemtothenewg ysystem



Operation, Support, and Security PhaseOperation,Support,andSecurityPhase

Thepurposeoftheoperation,support,andsecurityphase istoprovideongoingassistancefory p p g ganinformationsystemanditsusersafterthesystem is implementedsystemisimplemented

Perform Monitor Assess systemmaintenanceactivities

systemperformance

Assesssystemsecurity



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Link from left navigation, then click Chief Security Officer below Chapter 12

Operation, Support, and Security PhaseOperation,Support,andSecurityPhase

Acomputersecurityplan shoulddothefollowing:

Foreachrisk,

Identifyallinformation

Identifyallsecurityrisksthat may cause

identifythesafeguardsthatexist to detectassetsofan

organization

thatmaycauseaninformation

assetloss

existtodetect,prevent,andrecoverfroma

loss


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Video: Create a Hidden Operating SystemVideo:CreateaHiddenOperatingSystem

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SummarySummary

Systemd l t

Guidelinesfortdevelopment

phasessystem

development

Activitiesthatoccurduring system

Activitiesperformedduringduringsystem

development eachsystemdevelopmentphasep p


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Discovering Computers 2011

Living in a Digital World

Computers 2011

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Chapter12 Information System Development