Chapter_One Ethiopian course in campus.pdf

Chapter one

1. Chapter I
System Development life cycle
1 Compiled by Yilkal B.

2. 2
•Whatissystem?
•SystemComponents
•WhatisSystemAnalysisandDesign
•SystemDevelopmentLifeCycle(SDLC)
•SystemsPlanningandSelection
oIdentifyingandselectingSystemsDevelopmentproject
oInitiatingandPlanningSystemsDevelopmentproject
oStructuringSystemProcessRequirements
oStructuringsystemLogicRequirements
oStructuringSystemdataRequirements
•OverviewofStructuralParadigm
Chapter Outline
2Compiled by Yilkal B.

3. What is system?
➢ThewordSystemisderivedfromGreekwordSystema,whichmeansan
organizedrelationshipbetweenanysetofcomponentstoachieve
somecommongoalorobjective.
➢Asystemis“anorderlygroupingofinterdependentcomponentslinked
togetheraccordingtoaplantoachieveaspecificgoal.”
➢Itiscollectionofelementsorcomponentsthatorganizedforcommon
purposetoaccomplishoveralltasksorgoalormultipletasks.
e.g.trafficmanagementsystem,payrollsystem,automaticlibrary
system,humanresourcesinformationsystem.
3Compiled by Yilkal B.

4. Constraints of a System
❖Asystemmusthavethreebasicconstraints:
1.A system must have some structure and behavior which is
designed to achieve a predefined objective.
2.Interconnectivity and interdependence must exist among the
system components.
3.The objectives of the organization have a higher priority than the
objectives of its subsystems.
4Compiled by Yilkal B.

5. Properties of a System
Asystemhasthefollowingproperties
1.Organization:Itimpliesstructureandorder.Itisthearrangementof
componentsthathelpstoachievepredeterminedobjectives.
2.Interaction:Itisdefinedbythemannerinwhichthecomponentsoperate
witheachother.
✓E.g.,inanorganization,purchasingdepartmentmustinteractwithproduction
departmentandpayrollwithpersonneldepartment.
3.Interdependence:Imeanshowthecomponentsofasystemdependonone
another.Forproperfunctioning,thecomponentsarecoordinatedandlinked
togetheraccordingtoaspecifiedplan.Theoutputofonesubsystemisthe
requiredbyothersubsystemasinput.
5Compiled by Yilkal B.

6. Properties of a System
4.Integration
✓ItmeansIntegrationisconcernedwithhowasystemcomponents
areconnectedtogether.
✓hatthepartsofthesystemworktogetherwithinthesystemeven
ifeachpartperformsauniquefunction.
5.CentralObjective
✓Theobjectiveofsystemmustbecentral.
✓Itmayberealorstated.
✓Theusersmustknowthemainobjectiveofacomputerapplication
earlyintheanalysisforasuccessfuldesignandconversion.
5Compiled by Yilkal B.

7. Elements of a System
Thefollowingdiagramshowstheelementsofasystem
5Compiled by Yilkal B.

8. Cntd…
1.OutputsandInputs:Themainaimofasystemistoproduceanoutput
whichisusefulforitsuser.
✓Inputsaretheinformationthatentersintothesystemforprocessing.
✓Outputistheoutcomeofprocessing.
2.Processor(s):Theprocessoristheelementofasystemthatinvolvesthe
actualtransformationofinputintooutput.
✓Itistheoperationalcomponentofasystem.
✓Processorsmaymodifytheinputeithertotallyorpartially,dependingon
theoutputspecification.
✓Astheoutputspecificationschange,sodoestheprocessing.
✓Insomecases,inputisalsomodifiedtoenabletheprocessorforhandling
thetransformation. 5Compiled by Yilkal B.

9. Cntd…
3.Control:Thecontrolelementguidesthesystem.
➢Itisthedecisionmakingsubsystemthatcontrolsthepatternofactivities
governinginput,processing,andoutput.
➢ThebehaviorofacomputerSystemiscontrolledbytheOperatingSystem
andsoftware.Inordertokeepsysteminbalance,whatandhowmuch
inputisneededisdeterminedbyOutputSpecifications.
4.Feedback:Feedbackprovidesthecontrolinadynamicsystem.
➢Positivefeedbackisroutineinnaturethatencouragestheperformanceof
thesystem.
➢Negativefeedbackisinformationalinnaturethatprovidesthecontroller
withinformationforaction.
5Compiled by Yilkal B.

10. Cntd…
5.Environment:
➢itisthe“supersystem”withinwhichanorganizationoperates.
➢Itisthesourceofexternalelementsthatstrikeonthesystem.
➢Itdetermineshowasystemmustfunction.
6.BoundariesandInterface:
➢Asystemshouldbedefinedbyitsboundaries.
➢Boundariesarethelimitsthatidentifyitscomponents,processes,and
interrelationshipwhenitinterfaceswithanothersystem.
➢Theknowledgeoftheboundariesofagivensystemiscrucialin
determiningthenatureofitsinterfacewithothersystems.
5Compiled by Yilkal B.

11. Types of Systems
Thesystemscanbedividedintothefollowingtypes
a.PhysicalorAbstractSystems
I.Physicalsystems:aretangibleentities.
➢Wecantouchandfeelthem.
➢PhysicalSystemmaybestaticordynamicinnature.
E.g.,desksandchairsarethephysicalpartsofcomputercenterwhichare
static.
➢Aprogrammedcomputerisadynamicsysteminwhichprograms,data,
andapplicationscanchangeaccordingtotheuser'sneeds.
II.Abstractsystems:arenon-physicalentitiesorconceptualthatmaybe
formulas,representationormodelofarealsystem.
5Compiled by Yilkal B.

12. Cntd…
I.Anopensystem
➢Itmustinteractwithitsenvironment.
➢Itreceivesinputsfromanddeliversoutputs
totheoutsideofthesystem.
➢E.g.aninformationsystemwhichmustadapt
tothechangingenvironmentalconditions.
5
II.Aclosedsystem
➢Doesn’tinteractwithits
environment.
➢Itisisolatedfromenvironmental
influences.
➢Acompletelyclosedsystemisrare
inreality.
b.OpenorClosedSystems
C.AdaptiveandNonAdaptiveSystem
I.AdaptiveSystem:respondstothechangeintheenvironmentinawaytoimprove
theirperformanceandtosurvive.E.g.humanbeings,animals.
II.NonAdaptiveSystem:isthesystemwhichdoesnotrespondtotheenvironment.
E.g.machines.
Compiled by Yilkal B.

13. Cntd…
D.PermanentorTemporarySystem
I.PermanentSystem:itpersistsforlongtime.e.g.businesspolicies.
II.TemporarySystem:itismadeforspecifiedtimeandafterthattheyare
demolished.
E.g.,ADJsystemissetupforaprogramanditisdissembledaftertheprogram.
E.NaturalandManufacturedSystem
➢Naturalsystemsarecreatedbythenature.Forexample,Solarsystem,seasonal
system.
➢ManufacturedSystemistheman-madesystem.
Forexample,Rockets,dams,trains.
5Compiled by Yilkal B.

14. Cntd…
F.DeterministicorProbabilisticSystem
➢Deterministicsystemoperatesinapredictablemannerandtheinteractionbetween
systemcomponentsisknownwithcertainty.Forexample,twomoleculesof
hydrogenandonemoleculeofoxygenmakeswater.
➢ProbabilisticSystemshowsuncertainbehavior.Theexactoutputisnotknown.For
example,Weatherforecasting,maildelivery.
G.Social,Human-Machine,MachineSystem
I.SocialSystemismadeupofpeople.E,g.,socialclubs,societies.
II.InHuman-MachineSystem,bothhumanandmachinesareinvolvedtoperforma
particulartask.E,g.,Computerprogramming.
III.MachineSystemiswherehumaninterferenceisneglected.Allthetasksareperformed
bythemachine.E.g.,anautonomousrobot.
5Compiled by Yilkal B.

15. Cntd…
IV.Man–MadeInformationSystems
➢Itisaninterconnectedsetofinformationresourcestomanagedataforparticular
organization,underDirectManagementControl(DMC).
➢Thissystemincludeshardware,software,communication,data,andapplication
forproducinginformationaccordingtotheneedofanorganization.
Man-madeinformationsystemsaredividedintothreetypes:
1.FormalInformationSystem:Itisbasedontheflowofinformationintheformof
memos,instructions,etc.,fromtopleveltolowerlevelsofmanagement.
2.InformalInformationSystem:Thisisemployeebasedsystemwhichsolvesthe
daytodayworkrelatedproblems
3.ComputerBasedSystem:Thissystemisdirectlydependentonthecomputerfor
managingbusinessapplications.E,g.,automaticlibrarysystem.
5Compiled by Yilkal B.

16. Components of System
➢Componentsofsystemarepartsofsystem.
Componentsofinformationsystems:
➢Aninformationsystemisessentiallymadeupoffivecomponents.
1.Hardwareconsistsofinput/outputdevice,processor,operatingsystemetc.
2.Softwareconsistsofvariousprogramsandprocedures.
3.Databaseconsistsofdataorganizedintherequiredstructure.
4.Networkconsistsofhubs,communicationmediaandnetworkdevices.
5.Peopleconsistofdeviceoperators,networkadministratorsandsystem
specialist.
➢Informationprocessingconsistsofinput;dataprocess,datastorage,outputand
control.
5Compiled by Yilkal B.

17. System Development Life Cycle ( SDLc)
➢SDLCisaconceptualmodelwhichincludespoliciesandproceduresfor
developingoralteringsystemsthroughouttheirlifecycles.
➢SDLCisusedbyanalyststodevelopaninformationsystem.
➢AneffectiveSDLCshouldresultinahighqualitysystemthatmeetscustomer
expectations,reachescompletionwithintimeandcostevaluations,andworks
effectivelyandefficiently.
➢SDLCincludesthefollowingactivities:−
17
▪Deployment
▪Operations
▪Maintenance
▪Requirements
▪Design
▪Implementation
▪Testing
Compiled by Yilkal B.

18. Phases of SDLC
➢SDLCisasystematicapproachwhichexplicitlybreaksdowntheworkintophases
thatarerequiredtoimplementeithernewormodifiedInformationSystem.
18Compiled by Yilkal B.

19. Cntd…
1.PlanningorFeasibilityStudy
➢Definetheproblemandscopeofexistingsystem.
➢Overviewthenewsystemanddetermineitsobjectives.
➢ConfirmprojectfeasibilityandproducetheprojectSchedule.
➢Duringthisphase,threats,constraints,integrationandsecurityofsystemarealso
considered.
➢Afeasibilityreportfortheentireprojectiscreatedattheendofthisphase.
2.AnalysisandSpecification
➢Gather,analyze,andvalidatetheinformation.
➢Definetherequirementsandprototypesfornewsystem.
➢Evaluatethealternativesandprioritizetherequirements.
➢Examinetheinformationneedsofend-userandenhancesthesystemgoal.
19Compiled by Yilkal B.

20. Cntd…
➢AsoftwareRequirementSpecification(SRS)document,whichspecifiesthe
software,hardware,functional,andnetworkrequirementsofthesystemisprepared
attheendofthisphase.
3.SystemDesign
➢Includesthedesignofapplication,network,databases,userinterfaces,and
systeminterfaces.
➢TransformtheSRSdocumentintologicalstructure,whichcontainsdetailed
andcompletesetofspecificationsthatcanbeimplementedinaprogramming
language.
➢Createacontingency,training,maintenance,andoperationplan.
➢Reviewtheproposeddesign.Ensurethatthefinaldesignmustmeetthe
requirementsstatedinSRSdocument.
➢Finally,prepareadesigndocumentwhichwillbeusedduringnextphases.
12Compiled by Yilkal B.

21. Cntd…
4.Implementation
➢Implementthedesignintosourcecodethroughcoding.
➢Combineallthemodulestogetherintotrainingenvironmentthatdetectserrors
anddefects.
➢Atestreportwhichcontainserrorsispreparedthroughtestplanthatincludestest
relatedtaskssuchastestcasegeneration,testingcriteria,andresourceallocation
fortesting.
➢Integratetheinformationsystemintoitsenvironmentandinstallthenew
system.
12Compiled by Yilkal B.

22. Cntd…
5.Maintenance/Support
➢Includealltheactivitiessuchasphonesupportorphysicalon-sitesupport
forusersthatisrequiredoncethesystemisinstalling.
➢Implementthechangesthatsoftwaremightundergooveraperiodoftime,or
implementanynewrequirementsafterthesoftwareisdeployedatthe
customerlocation.
➢Italsoincludeshandlingtheresidualerrorsandresolveanyissuesthatmay
existinthesystemevenafterthetestingphase.
➢Maintenanceandsupportmaybeneededforalongertimeforlargesystems
andforashorttimeforsmallersystems.
12Compiled by Yilkal B.

23. Cntd…
12Compiled by Yilkal B.

24. System Analysis and Design (SAD)-Overview
❑Systemsdevelopmentissystematicprocesswhichincludesphases
suchas:
❖planning,
❖analysis,
❖design,
❖deployment,and
❖maintenance.
❑Wewillprimarilyfocuson
✓Systemsanalysis
✓Systemsdesign
7Compiled by Yilkal B.

25. Systems Analysis
➢SystemsanalysisisthepartoftheSDLCinwhichyoudeterminehowa
currentinformationsysteminanorganizationfunctions.
➢Itisaprocessofcollectingandinterpretingfacts,identifyingtheproblems,
anddecompositionofasystemintoitscomponents.
➢Itisconductedforthepurposeofstudyingasystemoritspartsinorderto
identifyitsobjectives.
➢Itisaproblemsolvingtechniquethatimprovesthesystemandensures
thatallthecomponentsofthesystemworkefficiently.
➢Analysisspecifieswhatthesystemshoulddo.
➢Therearethreepartstosystemanalysis:determiningrequirements,
structuringrequirements,andselectingthebestalternativedesignstrategy.
25Compiled by Yilkal B.

26. Systems Design
➢Itisaprocessofplanninganewbusinesssystemorreplacingan
existingsystembydefiningitscomponentsormodulestosatisfythe
specificrequirements.
➢Beforeplanning,youneedtounderstandtheoldsystemcarefullyand
determinehowcomputerscanbestbeusedinordertooperateefficiently.
➢SystemDesignfocusesonhowtoaccomplishtheobjectiveofthe
system.
➢SystemAnalysisandDesign(SAD)mainlyfocuseson:
▪Systems
▪Processes
▪Technology
26Compiled by Yilkal B.

27. Life Cycle of System Analysis and Design
➢Thefollowingdiagramshowsthecompletelifecycleofthesystemduring
analysisanddesignphase.
12Compiled by Yilkal B.

28. What is Information System Analysis & Design?
➢InformationSADistheprocessofdevelopingandmaintainingan
informationsystem.
➢ThemaingoalofSADistoimprovetheorganizationalsystemsthatcan
helpemployeesaccomplishtasksmoreeasilyandefficiently.
➢Theanalysisanddesignofinformationsystemsarebasedon:
▪Yourunderstandingoftheorganizationsobjective,structureandprocess.
▪Yourknowledgeofhowtoexploitinformationtechnologyforadvantage.
➢Inordertounderstandandfollowthesoftwareengineeringprocessthat
leadstothecreationofinformationsystem,provenmethodologies,
techniques,andtoolsarecentraltosoftwareengineeringprocess.
28Compiled by Yilkal B.

29. Cntd…
➢Methodologies:aresequencesofstepbystepapproachesthathelpdevelop
yourfinalprojecttheinformationsystem.
➢Techniques:areprocessesthatyou,asasystemanalyst,willfollowtohelp
ensurethatyourworkiswellthoughtout,complete,andcomprehensibleto
othersonyourprojectteam.
➢Tools:arecomputerprograms,suchasComputerAidedSoftware
Engineering(CASE)tools,thatmakeiteasytousespecifictechniques.
29Compiled by Yilkal B.

30. Types of Information System
➢Thereareactuallyseveraldifferenttypesofclassesofinformationsystems.
➢Theseclassesaredistinguishedfromeachotheronthebasisofwhatthe
systemdoesorbythetechnologyusedtoconstructthesystem.
➢Asasystemanalystworkingaspartofateam,youwillworkwithatleast
fourclassesofinformationsystem.
1.Transactionprocessingsystem.
2.Managementinformationsystem(Businesssupportsystem).
3.Decisionsupportsystem(forindividuals,groups,andexecutives).
4.Expertsystems(KnowledgemanagementSystem).
30Compiled by Yilkal B.

31. Types of Information System
1.TransactionProcessingSystem(TPS)
➢Itautomatesthehandlingofdataaboutbusinessactivitiesortransaction.
➢ForE.g.,abankstpswouldcaptureinformation'saboutwithdrawalsfrom
anddepositstocustomersaccounts.
➢ThegoalofTPSdevelopmentistoimprovetransactionprocessingby
speedingitup,usingfewerpeople,improvingefficiencyandaccuracy,
integratingitwithotherorganizationalinformationsystems,orproviding
informationnotpreviouslyavailable.
31Compiled by Yilkal B.

32. Cntd…
2.ManagementInformationSystem(MIS)(BusinessSupportSystems)
➢Itisacomputerbasedinformationsystemthattakestherawdataavailable
throughaTPSandconvertsthemintoameaningfullaggregatedform.
➢Thesesystemscananalyzetransactionaldata,generateinformationneeded
tomanageandcontrolbusinessprocess,andprovideinformationthatleads
tobetterdecisionmaking.
E.g.,whereasaTPSkeepstrackofsales,aMIScanpinpointwhichitemsareselling
slowlyandwhicharesellingquickly.
➢TheMISsystemcandirectthemanufacturingdepartmentonwhattoproduceand
when.
➢AnimportantfeatureofanMISisdecisionsupportcapabilitytoconductawhat–if
analysis. 32Compiled by Yilkal B.

33. Cntd…
3.DecisionSupportSystem(DSS):Itisdesignedtohelpdecisionmakerswith
decisions.
➢Whereas,anMISproducesareport,aDSSprovidesaninteractiveenvironmentin
whichdecisionmakerscanquicklymanipulatedataandmodelsofbusiness
operations.
➢ADSShasthreeparts:
▪Thefirstpartiscomposedofadatabase(maybeextractedfromTPSorMIS).
▪Thesecondpartconsistsofmathematicalorgraphicalmodelsofbusiness
process.
▪Thethirdpartismadeupofauserinterfacethatprovidesawayforthedecision
makertocommunicatewiththeDSS.
➢ADSSischaracterizedbylessstructuredandpredictableuse.
➢DSSsoftwaresupportscertaindecisionmakingactivities.
33Compiled by Yilkal B.

34. Cntd…
4.ExpertSystem(KnowledgeManagementSystem)
➢Anexpertsystem(ES)isdifferentfromanyoftheotherclassesof
informationsystems.
➢TheESreplicatesthedecisionmakingprocessratherthanmanipulating
information.
➢TypicallyuserscommunicatewithanESthroughaninteractivedialog.
➢TheESasksquestion(whichanexpertwouldask)andtheusersuppliesthe
answers.
➢Theanswersarethenusedtodeterminewhichrulesapply,andtheES
providesarecommendationbasedontherules.
34Compiled by Yilkal B.

35. Project management
➢Aprojectisaplannedundertakingofseriesofrelatedactivitiestoreachan
objectivethathasabeginningandanend.
➢Projectmanagementisanimportantaspectofthedevelopmentof
informationsystemsandacriticalskillforasystemanalyst.
➢Thefocusofprojectmanagementistoassurethatsystemdevelopment
projectsmeetcustomerexpectationsandaredeliveredwithinthetime
constraints.
➢Theprojectmanagerisasystemanalystwithavarioussetofskills-
management,leadership,technicalandcustomerrelationship.
➢projectmanagerisresponsibleforinitiating,planning,executing,and
closingdownthesystemsdevelopmentproject.
12Compiled by Yilkal B.

36. Project management
➢Theprojectmanagementprocessinvolves4phase
1.Initiatingtheproject:Duringthisphase,theprojectmanagerperformsseveral
activities.
➢Evaluatethesize,scope,andcomplexityoftheproject.
➢Establishesprocedurestosupportsubsequentactivities.
2.Planningtheproject:Thisphaseinvolvesdefiningclear,discreteactivitiesandthe
➢workneededtocompleteeachactivitywithinasingleproject.
3.Executingtheproject:Thisphaseputsthebaselineprojectplanintoaction.
➢Numberofactivitiesmustbeperformedinthisphaseaswell.
4.Closingtheproject:CloseProjectPhaseistheprocessoffinalizingallactivities
fortheproject,phase,orcontract.
➢Tobringtheprojecttoanend.
➢Projectscanconcludewithanaturalorunnaturaltermination. 12Compiled by Yilkal B.

37. Cntd…
12Compiled by Yilkal B.

38. Cntd…
Requestsforinformationsystemdevelopmentcancomefromthreekey
sources.
a.Managersandbusinessunitswhowanttoreplaceorextendanexisting
systeminordergainneededinformationortoprovideanewserviceto
customers.
b.Managerswhowanttomakeasystemmoreefficient,lesscostlytooperate,
orwanttomoveasystemtoanewoperatingenvironment.
c.Formalplanninggroupsthatwanttoimproveanexistingsysteminorderto
helptheorganizationmeetitscorporateobjectives,suchasprovidingbetter
customerservice.
38Compiled by Yilkal B.

39. Cntd…
RoleofSystemAnalyst
➢Thesystemanalystisapersonwhoisthoroughlyawareofthe
systemandguidesthesystemdevelopmentprojectbygivingproper
directions.
➢Heisanexperthavingtechnicalandinterpersonalskillstocarry
outdevelopmenttasksrequiredateachphase.
➢Hepursuestomatchtheobjectivesofinformationsystemwiththe
organizationgoal.
12Compiled by Yilkal B.

40. Cntd…
MainRoles:Definingandunderstandingtherequirementofuserthroughvarious
Factfindingtechniques.
➢Prioritizingtherequirementsbyobtaininguserconsensus.
➢Gatheringthefactsorinformationandacquirestheopinionsofusers.
➢Maintainsanalysisandevaluationtoarriveatappropriatesystemwhichismore
userfriendly.
➢Suggestsmanyflexiblealternativesolutions,pickthebestsolution,andquantify
costandbenefits.
➢Drawcertainspecificationswhichareeasilyunderstoodbyusersandprogrammer
inpreciseanddetailedform.
➢Implementedthelogicaldesignofsystemwhichmustbemodular.
➢Plantheperiodicityforevaluationafterithasbeenusedforsometime,and
modifythesystemasneeded.
12Compiled by Yilkal B.

41. Cntd…
AttributesofaSystemsAnalyst
➢Thefollowingfigureshowstheattributesasystemsanalystshouldpossess
12Compiled by Yilkal B.

42. Cntd…
InterpersonalSkills
➢Interfacewithusersandprogrammer.
➢Facilitategroupsandleadsmallerteams.
➢Managingexpectations.
➢Goodunderstanding,communication,sellingandteachingabilities.
➢Motivatorhavingtheconfidencetosolvequeries.
AnalyticalSkills
➢Systemstudyandorganizationalknowledge
➢Problemidentification,problemanalysis,andproblemsolving
➢Soundcommonsense
➢Abilitytoaccesstrade-off
➢Curiositytolearnaboutneworganization
12Compiled by Yilkal B.

43. Cntd…
ManagementSkills
➢Understandusersjargonandpractices.
➢Resource&projectmanagement.
➢Change&riskmanagement.
➢Understandthemanagementfunctionsthoroughly.
TechnicalSkills
➢Knowledgeofcomputersandsoftware.
➢Keepabreastofmoderndevelopment.
➢Knowofsystemdesigntools.
➢Breadthknowledgeaboutnewtechnologies.
12Compiled by Yilkal B.

44. Information Gathering Techniques
❖Themainaimoffactfindingtechniquesistodeterminetheinformation
requirementsofanorganizationusedbyanalyststoprepareapreciseSRS
understoodbyuser.
❖IdealSRSdocumentshould:−
➢becomplete,Unambiguous,andJargon-free.
➢specifyoperational,tactical,andstrategicinformationrequirements.
➢solvepossibledisputesbetweenusersandanalyst.
➢usegraphicalaidswhichsimplifyunderstandinganddesign.
❖Therearevariousinformationgatheringtechniques−
44
➢Interviewing
➢Questionnaires
➢ReviewofRecords,Procedures,
andForms
➢JointApplicationDevelopment(JAD)
➢SecondaryResearchorBackground
Reading
➢Observation
Compiled by Yilkal B.

45. Cntd…
A.Interviewing:Itcanbedoneintwoways:−
I.UnstructuredInterview:thesystemanalystconductsquestion-answersession
toacquirebasicinformationofthesystem.
II.StructuredInterview:Ithasstandardquestionswhichuserneedtorespond
ineitherclose(objective)oropen(descriptive)format.
AdvantagesofInterviewing
➢Thismethodisthebestsourceofgatheringqualitativeinformation.
➢Itisusefulforthem,whodonotcommunicateeffectivelyinwriting.
➢Informationcaneasilybevalidatedandcrosscheckedimmediately.
➢Itcanhandlethecomplexsubjects.
➢Itiseasytodiscoverkeyproblembyseekingopinions.
➢Itbridgesthegapsintheareasofmisunderstandingsandminimizesfuture
problems.
45Compiled by Yilkal B.

46. Cntd…
B.Questionnaires:usedbyanalysttogatherinformationaboutvariousissuesof
systemfromlargenumberofpersons.
Therearetwotypesofquestionnaires−
I.Open-endedQuestionnaires:Itconsistsofquestionsthatcanbeeasilyandcorrectly
interpreted.
II.Closed-endedQuestionnaires:Itconsistsofquestionsthatsystemanalyst
effectivelylistsallpossibleresponses,whicharemutuallyexclusive.
Advantagesofquestionnaires
➢Itisveryeffectiveinsurveyinginterests,attitudes,feelings,andbeliefsofusers
➢Itisusefultoknowwhatproportionofagivengroupapproves/disapproves
➢Itisusefultodeterminetheoverallopiniontothesystemproject.
➢Itismorereliableandprovideshighconfidentialityofhonestresponses.
➢Itisappropriateforelectingforstatisticaldatacollection
46Compiled by Yilkal B.

47. Cntd…
C.ReviewofRecords,Procedures,andForms:Reviewofexistingrecords,
procedures,andformshelpstoseekinsightintoasystemwhichdescribesthe
currentsystemcapabilities,itsoperations,oractivities.
Advantages
➢Ithelpsusertogainsomeknowledgeabouttheorganization.
➢Ithelpsindocumentingcurrentoperationswithinshortspanoftime.
➢Itcanprovideaclearunderstandingaboutthetransactionsthatarehandledinthe
organization,identifyinginputforprocessing,andevaluatingperformance.
➢Itcanhelpananalysttounderstandthesystemintermsoftheoperationsthatmust
besupported.
➢Itdescribestheproblem,itsaffectedparts,andtheproposedsolution.
47Compiled by Yilkal B.

48. Cntd…
D.Observation:Thisisamethodofgatheringinformationbynoticingand
observingthepeople,events,andobjects.
❖Theanalystvisitstheorganizationtoobservetheworkingofcurrentsystem
andunderstandstherequirementsofthesystem.
❖Advantages
➢Itisadirectmethodforgaininginformation.
➢Itisusefulinsituationwhereauthenticityofdatacollectedisin
question
➢Itproducesmoreaccurateandreliabledata.
➢Itproducesalltheaspectofdocumentationthatareincompleteand
outdated.
48Compiled by Yilkal B.

49. Cntd…
E.JointApplicationDevelopment(JAD):Itisanewtechniquedevelopedby
IBMwhichbringsowners,users,analysts,designers,andbuilderstodefineand
designthesystemusingorganizedandintensiveworkshops.
➢JADtrainedanalystactasfacilitatorforworkshopwhohassomespecialized
skills.
➢AdvantagesofJAD
❖Itsavestimeandcostbyreplacingmonthsoftraditionalinterviews
❖Itisusefulinorganizationalculturewhichsupportsjointproblemsolving.
❖Raisesformalrelationshipsamongmultiplelevelsofemployees.
❖Itcanleadtodevelopmentofdesigncreatively.
❖ItAllowsrapiddevelopmentandimprovesownershipofinformationsystem.
49Compiled by Yilkal B.

50. Cntd…
F.SecondaryResearchorBackgroundReading
➢Thismethodiswidelyusedforinformationgatheringbyaccessingthegleaned
information.
➢Itincludesanypreviouslygatheredinformationusedbythemarketerfrom
anyinternalorexternalsource.
Advantages
❖Itismoreopenlyaccessedwiththeavailabilityofinternet.
❖Itprovidesvaluableinformationwithlowcostandtime.
❖Itactasforerunnertoprimaryresearchandalignsthefocusofprimary
research.
❖Itisusedbytheresearchertoconcludeiftheresearchisworthitasitis
availablewithproceduresusedandissuesincollectingthem. 50Compiled by Yilkal B.

51. A. Systems Planning and Selection
➢TheProcessofIdentifyingandSelectingInformationSystemsDevelopmentProject.
➢Projectidentificationandselectionconsistsofthreeprimaryactivities:
I.identifyingpotentialdevelopmentprojects,
II.classifyingandrankingprojects,and
III.selectingprojectsfordevelopment.
1.Identifyingpotentialdevelopmentprojects:thisprocesscanbeperformedby
•Akeymemberoftopmanagement
•Asteeringcommittee(mangerswithaninterestinsystems.
•Userdepartments.
•Thedevelopmentgrouporaseniormanager.
Note:Projectsidentifiedbytopmanagementcommitteearereferredtoascoming
fromatopdownsourceandifitisfrommangers,businessunits,orthedevelopment
grouparereferredtoascomingfromabottom-upsource.
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52. Cntd…
2.Classifyingandrankingprojects:
➢Assessingthemeritofpotentialprojectisthesecondmajoractivityintheproject
identificationandselectionphase.
➢Aswithprojectidentification,classifyingandrankingprojectscanbeperformedby
topmangers,asteeringcommittee,businessunits,ortheISdevelopmentgroup.
➢Thefollowingarethecriteriacommonlyusedtoevaluateprojects.
a)valuechainanalysis
b)strategicalignment
c)potentialbenefits
d)resourceavailability
e)projectsize/duration
f)technicaldifficulty/risks
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53. Cntd…
3.Selectingprojectsfordevelopment
➢Theselectionofprojectsisthefinalactivityintheprojectidentificationand
selectionphase.
➢Theprimarydeliverable,orendproduct,fromtheprojectidentificationand
selectionphaseisascheduleofspecificISdevelopmentproject.
➢Theseprojectscomefrombothtop-downandbottom-upsources,andonce
selectedtheymoveintothesecondactivity,projectinitiationandplanning.
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54. Initiating & Planning Systems Development Project
➢The objective of project initiation and planning is to transform a vague system
request document into a tangible project description.
➢Therearetwomajoractivitiesthatoccurduringprojectinitiationandproject
planningthatprojectinitiationandprojectplanning.
A.Projectinitiation:
➢focusesonactivitiesthatwillhelporganizeateamtoconductprojectplanning.
➢Therearefivebasicactivitiesperformedduringprojectinitiation.
1.Establishingtheprojectinitiationteam.
2.Establishingarelationshipwiththecustomer.
3.Establishingtheprojectinitiationplan.
4.Establishingmanagementprocedure
5.Establishingtheprojectmanagementenvironmentandprojectworkbook.
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55. Cntd…
B.Projectplanning:thesecondactivitywhichfocusesondefiningclear,discrete
tasksandtheworkneededtocompleteeachtask.
➢Theobjectiveoftheprojectplanningprocessistoproducetwodocuments:a
BaselineProjectPlan(BPP)andtheStatementofWork(SOW).
➢Thefollowingaretheactivitiesperformedduringprojectplanning.
55
1.Describingtheprojectscope,alternatives
andfeasibility.
2.Dividingtheprojectintomanageable
tasks.
3.Estimatingresourcesandcreatingaresource
plan.
4.Developingapreliminaryschedule.
5.Developingacommunicationplans
6.Determiningprojectstandardsand
procedures
7.Identifyingandassessingrisks.
8.Creatingapreliminarybudget.
9.Developingastatementofwork.
10.Settingabaselineprojectplan.
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56. Cntd…
➢Themajoroutcomesanddeliverablesfromprojectinitiationandplanning
aretheBaselineProjectPlanandtheStatementofWork.
➢TheBaselineProjectPlan(BPP):containsallinformationcollectedand
analyzedduringtheprojectinitiationandplanningactivity.
➢Theplanreflectsthebestestimateoftheprojectsscope,benefits,costs,risks,
andresourcerequirementsgiventhecurrentunderstandingoftheproject.
➢TheStatementofWork(SOW):isashortdocumentpreparedforthe
customerthatdescribeswhattheprojectwilldeliverandoutlinesallwork
requiredcompletetheproject.
➢TheSOWisausefulcommunicationtoolthatassuresthatbothyouandyour
customerhaveacommonunderstandingoftheproject.
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57. Cntd…
BuildingtheBaselineProjectPlan
➢Alltheinformation'scollectedduringprojectinitiationandplanningare
collectedandorganizedintoadocumentcalledtheBaselineProjectPlan.
➢Anoutlineofabaselineprojectplancontainsfourmajorsections.
1.Introduction
2.Systemdescription
3.Feasibilityassessment
4.Managementissue
➢Thepurposeoftheintroductionistoprovideabriefoverviewoftheentire
documentandoutlinearecommendedcourseofactionfortheproject.
➢Theintroductionisoftenlimitedtoonlyafewpages.
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58. Cntd…
❑AssessingProjectFeasibility:
➢thespecificsofagivenprojectwilldictatewhichfactorsaremostimportant.
➢Mostfeasibilityfactorsfallintothefollowingsixcategories:
✓Economic
✓Operational
✓Technical
✓Schedule
✓LegalandContractual
✓Political
➢Theanalysisofthesesixfactorsformsthebusinesscasethatjustifiesthe
spendingofresourcesontheproject.
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59. Cntd…
I.AssessingEconomicFeasibility:Aprocessofidentifyingthefinancialbenefitsand
costsassociatedwithadevelopmentproject.
➢Economicfeasibilityisoftenreferredtoascost-benefitanalysis.
➢DeterminingProjectBenefits:aninformationsystemcanprovidemanybenefitsto
anorganization.Thesebenefitsarebothtangibleandintangible.
A.TangibleBenefits:isanitemthatcanbemeasuredindollarsandwithcertainty.
E.g.,oftangiblebenefitsincludereducedpersonnelexpense,lowertransaction
costs,orhigherprofitmargins.Itincludecostsofhardwarecosts,laborcosts,and
operationalcostsfromemployeetrainingandbuildinginnovations.
➢Mosttangiblebenefitsfitinoneormoreofthefollowingcategories.
59
➢Costreductionandavoidance
➢Errorreduction
➢Increasedflexibility
➢Increasedspeedofactivity
➢Improvementofmanagementplanningandcontrol
➢Openingnewmarketsandincreasingsales
opportunities
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60. Cntd…
B.IntangibleBenefits:refertoitemsthatcan’tbeeasilymeasureddollarsorwith
certainty.
➢Intangiblebenefitsmayhavedirectorganizationalbenefits,suchas
improvementofemployeemorale,customergoodwill,oroperational
efficiency.ortheymayhavebroadersocietalimplications,suchasthereduction
ofwastecreationorresourceconsumption.
➢Intangiblebenefitsinclude:
▪Competitivenecessity
▪Increasedorganizationalflexibility
▪Increasedemployeemorale
▪Promotionoforganizationallearningandunderstanding
▪Moretimelyinformation
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61. Cntd…
❑Besidetangibleandintangiblecosts,youcandistinguishsystemrelated
developmentcostsaseitheronetimeorrecurring.
61
➢Arecurringcostreferstoacost
resultingfromtheongoingevolution
anduseofthesystem.
E.g.,ofthesecoststypicallyinclude:
➢Applicationsoftwaremaintenance
➢Incrementaldatastorageexpense
➢Incrementalcommunications
➢Newsoftwareandhardwarerent
➢Consumablesuppliesandother
expenses.
(e.g.,paper,forms,datacenterpersonnel)
➢AOnetimecostreferstoacost
associatedwithprojectinitiation,
development,andthestartupofthe
system.
Thesecostsencompassthefollowing
activities:
➢Systemdevelopment
➢Newhardwareandsoftwarepurchase
➢Usertraining
➢Sitepreparation
➢Dataorsystemconversion
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62. Cntd…
❑AssessingOtherFeasibilityConcerns
I.OperationalFeasibility:theprocessofassessingthedegreetowhicha
proposedsystemsolvesbusinessproblemsortakesadvantageofbusiness
opportunities.
II.TechnicalFeasibility:theprocessofassessingthedevelopmentorganizations
abilitytoconstructtheproposedsystem.
III.ScheduleFeasibility:theprocessofassessingthedegreetowhichthepotential
timeframeandcompletiondatesforallmajoractivitieswithinaprojectmeet
organizationaldeadlinesandconstraintsforaffectingchange.
IV.LegalandContractualFeasibility:theprocessofassessingpotentiallegaland
contractualconsequencesduetotheconstructionofasystem.
V.PoliticalFeasibility:theprocessofevaluatinghowkeystakeholderswithinthe
organizationviewtheproposedsystem.Etc.
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63. Cntd…
❑Therearethreepartstosystemanalysis:
A.determiningrequirements,
B.structuringrequirements,and
C.selectingthebestalternativedesignstrategy.
A.Theprocessofdeterminingrequirements
➢Duringrequirementdetermination,youandotheranalystsgatherinformationon
whatthesystemshoulddofromasmanysourcesaspossible.
Suchsourcesincludeusersofthecurrentsystem,reports,forms,andprocedures.
➢DeliverablesandOutcomes:Theprimarydeliverablesfromrequirement
determinationarethetypesofinformationgatheredduringthedetermination
process.
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64. Cntd…
ModernmethodsfordeterminingsystemrequirementjointApplication
design(JAD)
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65. Cntd…
B.StructuringSystemRequirement
➢Duringrequirementstructuringyoustudytherequirementsandstructurethem
accordingtotheirinterrelationships,eliminatingtheredundancies.
➢Therearethreeprimaryactivitiesperformedduringrequirementstructuring.
I.ProcessModeling
II.LogicModeling
III.ConceptualDataModeling
I.ProcessModeling
➢Itinvolvesgraphicallyrepresentingtheprocess,oractions,thatcapture,
manipulate,store,anddistributedatabetweenasystemanditsenvironment
amongcomponentswithinasystem.
➢AcommonformofaprocessmodelisaDataFlowDiagram(DFD).
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66. Cntd…
➢ADFDisagraphicthatillustratesthemovementofdatabetweenexternal
entitiesandtheprocessanddatastoreswithinasystem.
➢Theanalysisteambeginstheprocessofstructuringrequirementswithan
abundanceofinformationgatheredduringrequirementsdetermination.
➢Instructuredanalysis,theprimarydeliverablesfromprocessmodelingarea
setofcoherent,interrelateddataflowdiagrams.
➢Deliverablesoftheprocessmodelingare:
-ContextDFD
-DFDsofcurrentphysicalsystem
-DFDsofnewlogicalsystem
-ThroughdescriptionofeachDFDcomponent
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67. Cntd…
➢First,acontextDFDshowsthescopeofthesystem,indicatingwhichelements
areinsideandoutsidethesystem.
➢Second,DFDofthecurrentsystemspecifywhichpeopleandtechnologiesareused
inwhichprocesstomoveandtransformdata,acceptinginputs,andproducing
outputs.
➢ThirdtechnologyindependentornewlogicalDFDshowsthedataflow
structureandfunctionalrequirementsofthenewsystem.
➢Finally,entriesforalloftheobjectsincludedinalldiagramsareincludedinthe
projectdictionaryorCASErepository.
➢DFDsareversatilediagrammingtoolswithonlyfoursymbols.
▪Itcanrepresentbothphysicalandlogicalinformationsystems.
▪ThefoursymbolsintheDFDrepresentdataflows,datastores,processes,and
sources/sinks(externalentities).
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68. Cntd…
II.LogicModeling:Itinvolvesrepresentingtheinternalstructureand
functionalityoftheprocessesrepresentedonDFD.
➢AlthoughDFDareverygoodforidentifyingprocess,theydonotshowthelogic
insidetheprocess.
➢Therearetwomethodsusedmostcommonlymodelingsystemprocess.
1.StructuredEnglish
2.DecisionTables
1)ModelingLogicwithStructuredEnglish
➢StartingwiththeprocessesdepictedinthevarioussetsofDFDyouandotherson
theanalysisteamhaveproduced,youmustnowbegintostudyanddocumentthe
logicofeachprocess.
➢StructuredEnglish:isamodifiedformofEnglishthatisusedtospecifythe
contentsofprocessboxesinDFD.
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69. Cntd…
➢ItusesasubsetofEnglishvocabularytoexpressinformationsystemprocess
procedures.
➢StructuredEnglishusesstrongverbssuchasread,write,print,sort,move,merge,
add,subtract,multiply,anddivide.
➢UnlikeregularEnglish,structuredEnglishdoesnotuseadjectivesoradverbs.
➢ItispossibletousestructuredEnglishtorepresentallthreeprocessestypicalto
structuredprogramming:sequence,conditionalstatements,andrepetitive.
E.g.Conditionalstatementscanberepresentedwithastructurelikethefollowing.
BEGINIF
IFQuantity-in-stockislessthanMinimum-order-quantity
THENGENERATEneworder
ELSEDOnothing
ENDIF
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70. Cntd…
2)ModelingLogicwithDecisionTables
➢Ifseveraldifferentconditionsareinvolved,andcombinationsoftheseconditions
dictated,thenstructuredEnglishmaynotbeadequateforrepresentingthelogic
behindsuchacomplicatedchoice.
➢ADecisionTableisadiagramofprocesslogicwherethelogicisreasonably
complicated.Allofthepossiblechoicesandtheconditionsofthechoicesdependon
arerepresentedintabularform.
Inconstructingadecisiontables,youmayactuallyfollowasetofbasicprocedures,
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71. Cntd…
III.ConceptualDataModelingandtheEntity-Relationship(E-R)Diagram
➢Thegoalofconceptualdatamodelistocaptureasmuchofthemeaningofdataas
possible.
➢Themoredetails(orwhatsomesystemsanalystscallbusinessrule)aboutdatathat
wecanmodel,thebetterthesystemwecandesignandbuild.
➢Thepurposeofaconceptualdatamodelistoshowasmanyrulesaboutthe
meaningandinterrelationshipsamongdataaspossible.
➢E-Rdatamodelsarecommonlyuseddiagramsthatshowhowdataareorganizedin
aninformationsystem.
➢ThemaingoalofconceptualdatamodelingistocreateaccurateE-Rdiagrams
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72. Cntd…
IntroductiontoEntity-Relationship(E-R)Modeling
➢E-Rdiagramisadetailedlogicalandgraphicalrepresentationoftheentities,
associations,anddataelementsforanorganizationorbusinessarea.
➢Thebasicentity-relationshipmodelingnotationusesthreemainconstructs:
dataentities,relationships,andtheirassociatedattributes.
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73. Cntd…
Entities:Anentityisaperson,place,object,eventorconcept.
Someexamplesofentityare:
➢Person:EMPLOYEE,STUDENT,PATIENT
➢Place:STATE,REGIONCOUNTRY,BRANCH
➢Object:MACHINE,BUILDING,AUTOMOBILE,PRODUCT
➢Event:SALE,REGISTRATION,RENEWAL
➢Concept:ACCOUNT,COURSE,WORKCENTER
Attributes:Anamedpropertyorcharacteristicsofanentitythatisofinteresttothe
organization.
Followingaresometypicalentitytypesandassociatedattributes:
➢STUDENT:Student_ID,Student_Name,Address,Phone_Number
Identifiers:Acandidatekeythathasbeenselectedastheunique,identifying
characteristicsforanentitytype.E,g.,fromStudent.
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74. Cntd…
MultivaluedAttribute
➢Anattributethatmaytakeonmorethanonevalueforeachentityinstance.Suppose
thatDep_Name(dependantname)isoneoftheattributesofEMPLOYEE.
➢Ifeachemployeecanhavemorethatonedependent,Dep_Nameisamultivalued
attribute.
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75. Cntd…
DegreeofaRelationship:Thedegreeofarelationshipisthenumberofentity
typesthatparticipateinthatrelationship.
➢relationshipsarelabeledwithverbphrase
➢ThethreemostcommonrelationshipsinE-Rdiagramsareunary(degree
one),binary(degreetwo),andternary(degreethree).
➢UnaryRelationshipAlsocalledarecursiverelationship;aunaryrelationship
isarelationshipbetweentheinstancesofoneentitytype.
➢BinaryRelationshipAbinaryrelationshipisarelationshipbetweeninstances
oftwoentitytypesandisthemostcommontypeofrelationshipencountered
indatamodeling.
➢TernaryRelationship:Aternaryrelationshipisasimultaneousrelationship
amonginstancesofthreeentitytypes.
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76. Cntd…
AssociativeEntities
➢Anentitytypethatassociatestheinstancesofoneormoreentitytypesand
containsattributesthatarepeculiartotherelationshipbetweenthoseentity
instances.
➢ThefollowingfigureillustratesanexampleofanAssociativeentity.
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77. Cntd…
C.SelectingtheBestAlternativeDesignStrategy
➢Selectingthebestalternativesysteminvolvesatleasttwobasicsteps:
(1)generatingacomprehensivesetofalternativedesignstrategiesand
(2)selectingtheonethatismostlikelytoresultinthedesiredinformationsystem,
givenalloftheorganizational,economic,andtechnicalconstraintsthatlimit
whatcanbedone.
➢Asystemdesignstrategyrepresentsaparticularapproachtodevelopingthe
system.
➢Itincludesstatementsonthesystem’sfunctionality,hardwareandsystem
softwareplatform,andmethodforacquisition.
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78. Cntd…
➢Theprimarydeliverablesfromgeneratingalternativedesignstrategiesand
selectingthebestoneare:
1)Atleastthreesubstantivelydifferentsystemdesignstrategiesforbuildingthe
replacementinformationsystem.
2)Adesignstrategyjudgedmostlikelytoleadtothemostdesirableinformation
system.
3)ABaselineProjectPlanforturningthemostlikelydesignstrategyintoaworking
informationsystem.
Note
➢Therequirementsandconstraintsofthereplacementsystemraisemanyissuesthat
analystsmustconsiderwhentheydevelopalternativedesignstrategies.
➢Issuesoffunctionalityhelpdeterminesoftwareandhardwareselection,
implementation,organizationallimitationssuchasavailablefundinglevels.
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79. Overview of Structural Paradigm
DevelopmentMethodologies
➢Apopulartraditionalmethodiscalledstructuredanalysis,
➢butanewerstrategycalledobject-orientedanalysisanddesignisalsoused
widely.Eachmethodoffersmanyvariations.
➢Someorganizationsalsodeveloptheirownapproaches.
StructuredAnalysis
➢Atraditionalsystemdevelopmenttechniqueistimetestedandeasytounderstand.
Becauseitdescribestheprocessthattransformsdataintousefulinformation,
structuredanalysisiscalledaprocess–centeredtechnique.
➢Inadditiontomodelingtheprocess,structuredanalysisincludesdataorganization
andstructure,relationaldatabasedesign,anduserinterfaceissues.
➢Itusesaseriesofphases,calledSDLCtoplananalyzedesign\,implementand
supportaninformationsystem.
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80. Overview of Structural Paradigm
Object–OrientedAnalysis
➢Whereasstructuredanalysisregardsprocessanddataasseparatecomponents,
objectoriented(O-O)analysiscombinesdataandtheprocessthatactonthe
dataintothingscalledObjects.
➢SystemanalysisusesO-Omethodstomodelrealworldbusinessprocessand
operations.
➢Theresultisasetofsoftwareobjectsthatrepresentactualpeople,things,
transactions,andevents.
OtherDevelopmentStrategies
➢InadditiontostructuredanalysisandO-Omethodologies,theremayothersystem
developmenttechniquescreatedbyindividualcompanies.
➢E.g.,MicrosofthasdevelopedanapproachcalledMicrosoftSolutionsFrame\work
(MSF).
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81. Structural vs Object oriented
ReadingAssignment:ApproachestoDevelopment
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82. End of chapter one
Any Question?
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