Software engineering norte Lec 1 Unit-1.ppsx

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1. CourseCode:CSC315 (CSIT5
th
Sem)

2. 2

3. The main objective ofthiscourse istoprovideknowledgeofdifferentconcepts
of systemanalysisanddesign sothatstudents willbeabletodevelopinformation
systemsusingdifferentmethodologies,tools,techniques,andapproaches.
CourseObjectives:
3

4. TextBook:
1.JosephS.ValacichandJoeyF.George,ModernSystemsAnalysisandDesign,
8
th
Edition,Pearson
2.AlanDennis,BarbaraHaleyWixom,andDavidTegarden,SystemsAnalysis
and Design–AnObject-OrientedApproachwithUML,5th Edition,Wiley

5. ReferenceBooks:
1.KennethE.Kendalland JulieE.Kendall,SystemAnalysisandDesign,9th
Edition,Pearson
2.JeffreyWhittenandLonnieBently,SystemAnalysisandDesignMethods,7th
EditionScottTilleyandHarryJ.Rosenblatt,SystemAnalysisandDesign,11th
Edition

6. CurriculumDesign/
MarksDistribution
TotalMarks:100
InternalAssessment:20 (MidTerm-4Pre-Final-4,Assignment-4,Presentation-4Attendance-4)
Lab/ProjectWork:20(Report-15,Presentation-5)
FinalBoardExamination: 60
Credit:3
ClassLoad:4.5Hrs. /Week (Theory: 3Hrs.Tutorial/Presentation:1.5Hrs.)

7. SN DifferentAspects
1 Attendance
2 Assignments/Tutorials
3 ClassTests&Assessments
4 ClassPerformance
5 Presentation
SNDifferentAspects
1Attendance
2ProjectWork&Report
3Viva&Presentation

8. FinalExaminationQuestionsFormat
[FM=60,PM=24,Time =3Hrs.]
SNQuestionType Numberof
Questions
Given
Marksper
Question
TotalMarks Time
1Section–‘A’
Long Questions
(Attempt any TWO
questions)
3 10 20
3Hrs.
2Section –‘B'
Short Questions
(AttemptanyEIGHT
questions)
9 5 8x5=40
Total 60

9. Note
Studentmustpass'InternalAssessment','PracticalAssessment'and'Final
Examination'separately.
Studentmustattendeachandeveryactivityof'InternalAssessment'
otherwisehe/shewill bedeclared as'NotQualified'forfinalExamination.

10. ChaptersandTeachingHours
UnitTitle Hours
1 Foundationsfor Systems Development 10
2 Planning 5
3 Analysis 13
4 Design 7
5 ImplementationandMaintenance 4
6 Introductionto Object-OrientedDevelopment 6
Total 45Hr

11. Laboratory/ProjectWorks




12. Unit1: :FoundationsforSystemsDevelopment(10Hrs.)
1.1The SystemsDevelopment
Environment
Introduction (Information System and its
Types,SystemAnalysisand Design);
AModernApproachtoSystemsAnalysis
andDesign;
Developing Information Systems and the
Systems
DevelopmentLifeCycle;
TheHeart oftheSystems
Development ProcessandTraditional
Waterfall
SDLC;
CASETools
1.2Other Approaches
Prototyping;
Spiral;
RapidApplication
Development;
IntroductiontoAgileDevelopment
1.3 Managing theInformation
SystemsProject
Introduction
ManagingInformationSystemsProject
RepresentingandSchedulingProjectPlans
UsingProjectManagementSoftware

13. 13

14. Objectives?
Understand thefundamentalsystemsdevelopmentlifecycleanditsfourphases.
Understandthe evolutionof systemsdevelopmentmethodologies.
BefamiliarwiththeUnifiedProcessand itsextensions.
Befamiliarwiththedifferentrolesontheprojectteam.

15. WhyShouldWeCare?
Wouldyoubuya carthatonlyhada 28%chance
ofdrivingoff thelotwithnoproblems?

16. RecentSignificantITFailures
Company Year Outcome
HudsonBay(Canada)
2005 Inventory system problems lead to $33.3
millionloss.
UKInlandRevenue
2004/5$3.45billiontax-creditoverpayment
causedbysoftwareerrors.
AvisEuropePLC(UK)
2004 Enterpriseresourceplanning(ERP)
systemcancelledafter$54.5million
spent.
FordMotorCo.
2004 Purchasing system abandoned after
deployment costing approximately $400
M
Hewlett-PackardCo.
2004 ERPsystemproblemscontributeto $160
millionloss.
AT&TWireless
2004 Customer relationsmanagement
systemupgradeproblemsleadto
$100Mloss

17. SuccessfulProjects
•Cost
Atprojectcompletion,nomoremoneyhasbeenspentthanwasoriginallyallocated.
•Schedule
The projectis deliverednolaterthantheoriginaldeliverydate.
•Performance
Whendelivered,theprojecthasallfeaturesandfunctionalitythatwereoriginally
requiredofit.

18. SystemProjectOverview
ScopeDefinition
–Istheprojectworthlookingat?
ProblemAnalysis
–Isa new systemworthbuilding?
RequirementsAnalysis
–Whatdotheusersneedandwantfromthenewsystem?
LogicalDesign
–Whatmustthenewsystemdo?
DecisionAnalysis
–Whatisthebestsolution?
18

19. ©spickmlk 19

20. Unit1: :FoundationsforSystemsDevelopment(10Hrs.)
1.2Other Approaches
Prototyping;
Spiral;
RapidApplication
Development;
IntroductiontoAgileDevelopment
1.3 Managing theInformation
SystemsProject
Introduction
ManagingInformationSystemsProject
RepresentingandSchedulingProjectPlans
UsingProjectManagementSoftware
1.1The SystemsDevelopment
Environment
Introduction (Information System and its
Types,SystemAnalysisand Design);
AModernApproachtoSystemsAnalysis
andDesign;
Developing Information Systems and the
Systems
DevelopmentLifeCycle;
TheHeart oftheSystems
Development ProcessandTraditional
Waterfall
SDLC;
CASETools
20

21. 1.1TheSystemDevelopment
Environment
21

22. DefinitionofSystem
Asystemisanorderlygroupingofinterdependentcomponentslinkedtogether
accordingtoaplantoachievea specificobjective.
Asystemisacollectionofcomponents(subsystems)thatworktogethertorealize
some objective.
Forexample,thelibrarysystemcontainslibrarians,books,andperiodicalsas
componentstoprovide knowledgeforitsmembers.
Asetofdetailedmethods,proceduresandroutinesestablishedorformulationto
carryoutspecifyactivity,performaduty or solveaproblem.

23. DefinitionofSystem

24. DefinitionofSystem

25. System
Everysystemhasthreeactivitiesorfunctions.Theseactivitiesareinput,
processingandoutput.
Input:Itinvolvescapturingandassemblingelementsthatenterthesystemtobe
processed.Inputstothesystemareanythingtobecapturedbythesystemfromits
environment.Forexample,rawmaterials.
Processing:Itinvolvestransformationprocessesthatconvertinputtooutput.For
example, amanufacturingprocess.
Output:Itinvolvestransferringelementsthathavebeenproducedbya
transformationprocesstotheirultimatedestinations.Outputsarethethings
producedbythesystemandsentintoitsenvironment.Forexample,finished
products.

26. System
Thesystemalsoincludesothertwoadditionalactivities.Theseactivitiesinclude
feedbackandcontrol.
Feedback:Itisdataabouttheperformanceofasystem.Itistheideaof
monitoringthecurrentsystemoutputandcomparingittothesystemgoal.Any
variationfromthegoalarethenfedbackintothesystemandusedtoadjustitto
ensurethatitmeetsitsgoal.Forexample,dataaboutsalesperformanceis
feedbacktoasalesmanager.
Control:Itinvolvesmonitoringandevaluatingfeedbacktodeterminewhethera
systemismovingtowardtheachievementofitsgoals.Thecontrolfunctionthen
makesnecessaryadjustmentstoasystem’sinputandprocessingcomponentsto
ensurethatitproducesproperoutput.Forexample,asalesmanagerexercises
control.

27. CharacteristicsofaSystem
Organization
Interaction
Interdependence
Integration
CentralObjective

28. CharacteristicsofaSystem
Organization-Itimpliesstructureandorder.
Interaction-Itreferstomannerinwhicheachcomponentfunctionswithother
componentsofthesystem.
Interdependence-Units/partsaredependentoneach other.
Integration-Thepartsofasystemworktogetherwithinthesystemeventhough
eachpart performsauniquefunction.
CentralObjective-Objectivemayberealorstated.Allthecomponentswork
togethertoachieve thatparticularobjective.

29. WhySystemAnalysis?
Thedissectionofa systemintoitscomponentpiecestostudyhowthosecomponent
pieces interactandwork.
(1)Thesurveyandplanning
(2)Thestudyandanalysis
(3)Thedefinition

30. WhatisSystemDesign?
Theprocessofdefiningthearchitecture,components,modules,interfacesand
datafor a systemtosatisfyspecifiedrequirementsiscalledSystem Design.

31. Needfor SystemAnalysisandDesign
Installingasystemwithoutproperplanningleadstogreatuserdissatisfactionand
frequentlycausesthesystemto fallinto disuse.
Lends structuretotheanalysisanddesign ofinformationsystems.
Aseriesofprocessessystematicallyundertakentoimproveabusinessthroughthe
use ofcomputerizedinformationsystems

32. WhatisanInformationSystem?
Asystemthatprovidesinformationtopeopleinanorganizationiscalled
informationsystem(IS).
Aninformationsystemisanarrangementofpeople,data,processes,interfaces,
networks,andtechnologythatinteractforthepurposeofsupportingand
improvingbothday-to-dayoperationsinabusiness(sometimescalleddata
processing),aswellassupportingtheproblemsolvinganddecisionmaking
needsofmanagement(sometimescalledinformationservices).

33. InformationSystems
Anyorganized
combination of
people,hardware,
software,
communication
networks, data
resources,and
policies and
proceduresthatstores,
retrieves, transforms
and disseminates
information in an
organization

34. InformationSystem
Informationsystemsinorganizationscaptureandmanagedatatoproduceuseful
informationthatsupportsanorganizationanditsemployees,customers,suppliers
andpartners.So,manyorganizationsconsiderinformationsystemtobethe
essentialone.
Informationsystemsproduceinformationbyusingdataaboutsignificant
people,places,andthingsfromwithintheorganizationand/orfromtheexternal
environmenttomakedecisions,controloperations,analyzeproblems,and
createnewproductsorservices
Informationisthedatashapedintoameaningfulform.Data,ontheotherhand,
arethecollectionofrawfactsrepresentingeventsoccurringinorganizationsorthe
environmentbeforetheyhavebeenorganizedandarrangedintoaformthat
peoplecanunderstandanduse.

35. InformationSystem
Thethreeactivitiestoproduceinformationinaninformationsystemareinput,
processing,and output.
Inputcapturesorcollectsrawdatafromwithintheorganizationorfromits
externalenvironmentforprocessing.
Processingconvertstheserawdataintothemeaningfulinformation.
Outputtransfersthisinformationtothepeoplewhowilluseitortotheactivities
forwhich itwillbeused.
Informationsystemsalsorequirefeedback,whichisusedtomonitorthecurrent
informationsystemoutputandcompareittothesystemgoal.

36. InformationSystem

37. OperationSupportSystem ManagementSupportSystem
TransactionProcessingSystem
ProcessControl System
Enterprise CollaborationSystem
SpecializedProcessingSystem
ManagementInformationSystem
DecisionSupportSystem
ExecutiveInformationSystem
SpecializedProcessingSystem
ExpertSystem
Knowledge
Management
System
Strategic
Information
System
Functional
Business
System
InformationSystem
SupportBusinessOperations SupportManagementDecisionMaking
TypesofInformationSystems

38. TypesofInformationSystem(IS)
1.TransactionProcessingSystem(TPS)
2.ManagementInformationSystem(MIS)
3.DecisionSupportSystem(DSS)
4.ExpertsSystem

39. TransactionProcessingCycle
Inquiry
Processing
Data
Entry
Document
andReport
Generation
DataBase
Maintenance
Transaction
Processing
•Batch
•Online/Real-
Time

40. TransactionProcessingSystem(TPS)
TransactionProcessingSystemareinformationsystemthatprocessesdataresulting
fromtheoccurrencesofbusinesstransactions
Theirobjectivesaretoprovidetransactioninordertoupdaterecordsandgenerate
reportsi.e.toperformstorekeepingfunction
Thetransactionisperformedintwoways:BatchingprocessingandOnline
transactionprocessing.

41. TPS
systemistoanswerroutineThemainobjectiveofatransactionprocessing
questionssuchas;
Howmanyprintersweresoldtoday?
Howmuchinventorydowehaveathand?
WhatistheoutstandingdueforJohnDoe?

42. TPS
Examples of transactionprocessing systemsinclude;
Pointof SaleSystems–recordsdailysales
Payrollsystems–processingemployeessalary,loansmanagement,etc.
StockControl systems –keepingtrackofinventorylevels
Airlinebooking systems–flightsbookingmanagement

43. ManagementInformationSystem(MIS)
ManagementInformationSystems (MIS)
–Providesinformationintheformofreports&displays
–Example:dailysalesanalysisreports
ManagementInformationSystemisdesignedtotakerelativelyrawdataavailable
throughaTransactionProcessingSystemandconvertthemintoasummarizedand
aggregatedformforthemanager,usuallyinareportformat.Itreportstendingto
beusedbymiddlemanagementandoperationalsupervisors.
ManagementInformationSystems(MIS)areusedbytacticalmanagerstomonitor
theorganization'scurrentperformancestatus.Theoutputfromatransaction
processingsystemisusedasinputtoamanagementinformationsystem.

44. MIS
ManydifferenttypesofreportareproducedinMIS.Someofthereportsarea
summaryreport,on-demandreport,ad-hocreports,etc.
TheMISsystemanalyzestheinputwithroutinealgorithmsi.e.aggregate,compare
andsummarizestheresultstoproducedreportsthattacticalmanagersuseto
monitor,controlandpredictfutureperformance.
Forexample,inputfromapointofsalesystemcanbeusedtoanalyzetrendsof
productsthatareperformingwellandthosethatarenotperformingwell.This
informationcanbeusedtomakefutureinventoryordersi.e.increasingordersfor
well-performingproductsandreducetheordersofproductsthatarenot
performingwell.

45. MIS
MISsystemsprovidetheinformationneededtomakethestructureddecisionand
basedontheexperienceofthetacticalmanagers,theymakejudgmentcallsi.e.
predicthowmuchofgoodsorinventoryshouldbeorderedforthesecondquarter
basedonthesalesofthefirstquarter
Examples ofmanagementinformationsystemsinclude;
Salesmanagementsystems–theyget inputfromthepointofsalesystem
Budgetingsystems–givesanoverviewofhowmuchmoneyisspentwithinthe
organizationfortheshortandlongterms.
Humanresourcemanagementsystem–overallwelfareoftheemployees,staff
turnover,etc.

46. ©spickmlk 46
DSS
Components

47. DecisionSupportSystem(DSS)
DecisionSupportSystems(DSS)
–Interactiveandadhocsupport
–Productpricing,riskanalysis
–Example:awhat-ifanalysistodeterminewheretospendadvertising
dollars,howmuchtoproduce
Decisionsupportsystemsareusedbyseniormanagementtomakenon-routine
decisions.Decisionsupportsystemsuseinputfrominternalsystems(transaction
processingsystemsandmanagementinformationsystems)andexternalsystems.
Themainobjectiveofdecisionsupportsystemsistoprovidesolutionstoproblems
thatareuniqueandchangefrequently.Decisionsupportsystemsanswerquestions
suchas;
Whatwouldbetheimpactofemployees'performanceifwedoubletheproductionlot
atthefactory?
Whatwouldhappentooursalesifa newcompetitorenteredthemarket?

48. DSS
Decisionsupportsystemsusesophisticatedmathematicalmodels,andstatistical
techniques(probability,predictivemodeling,etc.)toprovidesolutions,andthey
areveryinteractive.
Examplesof decisionsupportsystemsinclude;
Financialplanningsystems–itenablesmanagerstoevaluatealternativewaysof
achievinggoals.Theobjectiveistofindtheoptimalwayofachievingthegoal.For
example,thenetprofitforabusinessiscalculatedusingtheformulaTotalSalesless
(CostofGoods+Expenses).Afinancialplanningsystemwillenablesenior
executivestoaskwhatifquestionsandadjustthevaluesfortotalsales,thecostof
goods,etc.toseetheeffectofthedecisionandonthenetprofitandfindthemost
optimalway.
Bankloanmanagementsystems–itisusedtoverifythecreditoftheloan
applicantandpredictthelikelihoodoftheloanbeingrecovered.

49. ExpertsSystem
•AnExpertSystem(ES)
–Aknowledge-based information system
–Contain knowledgeaboutaspecific, complexapplication area
–Actsas an expertconsultantto endusers
Expertssystemsincludeexpertiseinordertoaidmanagersindiagnosingproblems
orinproblem-solving.Thesesystemsarebasedontheprinciplesofartificial
intelligenceresearch.
ExpertsSystemsisaknowledge-basedinformationsystem.Itusesitsknowledge
aboutaspecifyareatoactasanexpertconsultanttousers.
Knowledgebaseandsoftwaremodulesarethecomponentsofanexpertsystem.
Thesemodulesperforminferenceontheknowledgeandofferanswerstoauser’s
question

50. Componentsof anExpertSystem

51. ExecutiveManagementSystem(EIS)
ExecutiveInformationSystems(EIS)
–Criticalinformationforexecutives andmanagers
–Example:easyaccesstoactionsofcompetitors,systemfor
accesstoanalysisofbusinessperformance
SeniormanagersofanorganizationusetheEIS.Therefore,itmustbeeasytouseso
thatexecutivescanuseitwithoutanyassistance.
EIScandotrendanalysis, exception reportingandhavedrill-downcapabilities.
Theresultsareusuallypresentedinagraphicalformtailoredtotheexecutive’s
informationneeds

52. SystemsAnalysisandDesign
Amethodusedbycompaniestocreateandmaintainsystemsthatperformbasic
businessfunctions
Maingoalistoimproveemployeeefficiencybyapplyingsoftwaresolutionstokey
businesstasks
Astructuredapproachmustbeused in ordertoensuresuccess

53. SystemsAnalysisandDesign
Systemanalysisanddesignisacomplex,challenging,andsimulating
organizationalprocessthatateamofbusinessandsystemsprofessionalsusesto
developandmaintaincomputer-basedinformationsystems.
Itisanorganizationalimprovementprocess.Informationsystemsarebuiltand
rebuiltfororganizationalbenefits.
Animportant(butnottheonly)resultofsystemanalysisanddesignisapplication
softwarei.e.softwaredesignedtosupportorganizationalfunctionsorprocesses
suchasinventorymanagement,payroll,ormark-sheetanalysis.

54. SystemsAnalysisandDesign
Inadditiontoapplicationsoftware,thetotalinformationsystemincludesthe
hardwareandsystemssoftwareonwhichtheapplicationsoftwareruns,
documentationandtrainingmaterials,thespecificjobrolesassociatedwiththe
overallsystem,controlsandthepeoplewhousethesoftwarealongwiththeirwork
methods.
Insystemsanalysisanddesign,weusevariousmethodologies,techniquesand
toolsthathavebeendeveloped,tested,andwidelyusedovertheyearstoassist
peopleduringsystemanalysisanddesign.

55. SystemsAnalysisandDesign

56. SystemsAnalysisandDesign
Methodologiesarecomprehensive,multistepapproachestosystemsdevelopment
thatwillguideyourworkandinfluencethequalityofyourfinalproduct:the
informationsystem.
Methodologiesuseastandard setofsteps.
Amethodologyadoptedbyanorganizationwillbeconsistentwithitsgeneral
managementstyle.
Most methodologiesincorporateseveraldevelopmenttechniques.

57. SystemsAnalysisandDesign
Techniquesareparticularprocessesthatwillhelptoensurethatyourworkiswell
thought-out,complete,andcomprehensibletoother on theprojectteam.
Techniquesalsoprovidesupportforawiderangeoftaskslikeconducting
interviews,planningandmanagingtheactivitiesinasystemdevelopmentproject,
diagrammingthesystem’slogic,anddesigningthereportsthatthesystemwill
generate.

58. SystemsAnalysisandDesign
Toolsaretypicallycomputerprogramsthatmakeiteasytouseandbenefitfrom
thetechniquesandtofaithfullyfollowtheguidelinesoftheoveralldevelopment
methodology.
Tobeeffective,bothtechniquesandtoolsmustbeconsistentwithanorganizations
systemdevelopmentmethodology.Thesemakeeasyforsystemdevelopersto
conductthestepsinmethodology.

59. ImportanceofSystemsAnalysisandDesign
Systemsanalysisanddesignisthecollectionofimportantactivitiesthattakesplace
whennewinformationsystemsarebeingbuiltorexistingonesarechanged.
Alltheactivitiesareneeded tobuildgoodinformationsystems.
Thesystemsdevelopedbyusingsystemsanalysisanddesignactivitiesfulfillthe
requirementsoforganizations’personnel.
Furthermore,wecandevelopinformationsystemseasilyandrapidlybecausethere
are lotsofsupportingmethodologies, tools,andtechniques.

60. ImportanceofSystemsAnalysisandDesign
Theinformationsystemcanbe builtinthemosteffectiveway.
Thesystemsalsofitintoanexistingenvironmentandwillbeveryeasytouseand
maintain.
Byfollowingtheactivitiesinvolvedinsystemsanalysisanddesign,wecandevelop
highqualityinformationsystemwithinallocatedbudgetandtime.

61. SystemOwners
Systemowners aretheinformationsystem’ssponsorsand chiefadvocates.
Theyareusuallyresponsibleforfundingtheprojectofdevelopment,operate,and
maintaintheinformationsystem.
Theyareinterestedwith-howmuchwillthesystemcost?Andhowmuchvalueor
whatbenefitwillthesystemreturntothebusiness?
Everyinformationsystemhasoneormoresystemowners.Theyusuallycomefrom
theranksofmanagerstosupervisors.

62. SystemUsers
Theseare thepeoplewhouseorare affectedby theinformationsystem onaregular
basis.
Theyareconcernedwiththesystem’sfunctionalityrelatedwiththeirjobsandthe
system’seaseoflearning anduse.
Asystemusermaycapture,validate,enter,respond,storeandexchangedataand
information.
Systemusersarealsocalledclients.Toknowbusinessrequirements,discussions
with most usersneed tobekept.

63. SystemDesigners
Thesearetechnologyspecialistswhotranslatesystemusers’businessrequirements
andconstraintsinto technicalsolutions.
Theseareinterestedininformationtechnologychoicesandthedesignofsystems
withintheconstraintsofthechosentechnology.
Theydesignthecomputerdatabase,inputs,outputs,screens,networks,and
programsthatwillmeetthesystemusers’requirements.Thesedesignsguidethe
constructionofthefinalsystem.

64. SystemBuilders
Thesearealsotechnologyspecialistswhoconstructinformationsystemsand
componentsbasedonthedesignspecifications generatedbythesystemdesigner.

65. SystemsAnalysts
Although,manypeopleinorganizationsareresponsibleforsystemsanalysisand
design,inmostorganizationsthesystemsanalysthastheprimaryresponsibility.
Theprimaryroleofasystemsanalystistostudytheproblemsandneedsofan
organizationinordertodeterminehowpeople,methodsandinformation
technologycanbest becombinedtobringaboutimprovementsin theorganization.
Systemanalystsidentifyandvalidateproblemsandneedsandensure thatthe
technical solution fulfills these problemsand needs.
Systemsanalystsstudythesystemandidentifyandvalidateitsproblemsandneeds
forsystemownersandusersandensurethatthetechnicalsolutionfulfillsthe
businessneeds

66. ProjectManagers
Tobuildagoodinformationsystemandapplicationsallthestakeholdersmust
worktogetheras ateam.Teamsrequireleadership.
Forthisreason,usuallyoneormoreofthesestakeholderstakesontheroleof
projectmanagertoensurethatsystemsaredevelopedontime,withinbudgetand
acceptablequality.
So,projectmanagerisresponsibleforplanning,monitoring,andcontrolling
projectswithrespecttoschedule,budget,deliverables,customersatisfaction,
technicalstandardsandsystemquality.

67. SystemAnalyst
Manyorganizationsconsiderinformationsystemsandcomputerapplicationsas
essentialtotheirabilitytocompeteorgaincompetitiveadvantage.
Informationhasbecomeamanagementresourceequalinimportancetoproperty,
facilities,employees,andcapital.
Allworkersneedtoparticipateinthedevelopmentofthesesystemsand
applications–notjustthecomputerandinformationspecialists.
Butonespecialistplaysaspecialroleinsystemsandapplicationsdevelopment,
thesystemsanalyst.
A systemsanalyst(s)facilitatesthedevelopmentofinformationsystemsand
computerapplications.

68. SystemAnalyst
Thesystemsanalyst performssystemsanalysisand design.
Systemsanalysisisthestudyofabusinessproblemdomainforthepurposeof
recommendingimprovementsandspecifyingthebusinessrequirementsforthe
solution.
Systemsdesignisthespecificationorconstructionofatechnical,computer-based
solutionforthebusinessrequirementsidentifiedina systemsanalysis.

69. TheSystemsAnalystAsAModernBusiness
ProblemSolver
WhydobusinessesneedSystemsAnalysts?
Thesystemanalystbridgesthecommunicationsgapbetweenthosewhoneedthe
computerandthosewhounderstandthetechnology

70. WhatisaSystemsAnalyst?
Systems analysts are peoplewho understandbothbusinessandcomputing.
Systemsanalystsstudybusinessproblemsandopportunitiesandthentransform
businessandinformationrequirementsofthebusinessintothecomputer-based
informationsystemsandcomputerapplicationsthatareimplementedbyvarious
technicalspecialistsincludingcomputerprogrammers

71. WhatisaSystemsAnalyst?
Aformaldefinition:
Asystemsanalystfacilitatesthestudyoftheproblemsandneedsofabusinessto
determinehowthebusinesssystemandinformationtechnologycanbestsolvethe
problemandaccomplishimprovementsforthebusiness.
Theproductofthisactivitymaybeimprovedbusinessprocesses,improved
informationsystems,orneworimprovedcomputerapplicationsfrequentlyall
three.

72. SystemsAnalyst
When informationtechnologyisused,thesystems analyst is responsiblefor:
theefficientcaptureofdatafromitsbusinesssourcetheflowofthatdatatothecomputerthe
processingandstorageofthatdatabythecomputertheflowofusefulandtimely
informationbacktothebusinessanditspeople

73. RolesoftheSystemAnalyst
The analystplaysakey rolein informationsystemsdevelopmentprojects.
Mustunderstandhowtoapplytechnologytosolvebusinessproblems.
Analystmayserveas changeagentswhoidentifytheorganizationalimprovement.

74. PreparingFora Careerasa SystemsAnalyst
(Or,SkillsNeeded)
WorkingKnowledgeofInformation Technology
ProgrammingExperienceand Expertise
GeneralBusinessKnowledge
Problem-SolvingSkills
CommunicationsSkills
InterpersonalRelationsSkills
FlexibilityandAdaptability
CharacterandEthics
SystemsAnalysisandDesignSkills

75. SystemDevelopmentLifeCycle(SDLC)
Mostorganizationsuseastandardsetofsteps,calledasystemsdevelopment
methodology todevelop andsupporttheirinformationsystems.
Itisastandardprocessfollowedinanorganizationtoconductallthesteps
necessary toanalyze,design,implement,andmaintaininformationsystems.
Andsystemsdevelopmentlifecycle(SDLC)isthetraditionalmethodologyusedto
develop, maintain,and replaceinformationsystems.

76. SDLC
Itincludes different phasesasshownin thefigurebelow.
ThisrepresentationofSDLCissometimesreferredtoasthewaterfall
model orclassiclifecycle.

77. SDLC
Thefirstphaseiscalledplanning.
Inthisphase,someoneidentifiestheneed foraneworenhancedsystem.
Theseneedsarethenanalyzed,prioritizedandarrangedintoaplanfortheIS
department.
Here,apotentialinformationsystemsprojectisexplainedandanargumentfor
continuingornotcontinuingwiththeprojectispresented;adetailedplanisalso
developedforconductingtheremainingphasesortheSDLCfortheproposed
system

78. SDLC
Thenextphaseiscalledanalysis.
Duringthisphase,theanalyststudiesthecurrentsystemandproposesalternative
replacementsystems.
Here,theanalystthoroughlystudiestheorganization’scurrentproceduresandthe
informationsystemsused toperformorganizationaltasks.
Theanalystworkwithuserstodeterminewhattheuserswantfromaproposed
system.
Theanalystcarefullystudiesanycurrentsystems,manualandcomputerized,that
might bereplaced orenhancedaspartofthisproject.

79. SDLC
Theanalyststudiestherequirementsandstructuresthemaccordingtotheir
interrelationshipsandeliminatesanyredundancies;generatesalternativeinitial
designstomatchtherequirements;comparethesealternativestodeterminewhich
bestmeetstherequirementswithinthecost,labor,andtechnicallevelsthe
organizationiswillingtocommittothedevelopmentprocess.
Theoutputofthisphaseisadescriptionoftherecommendedalternativesolution.
Oncetherecommendationisacceptedbyowners,youcanbegintomakeplansto
acquireanyhardwareandsystemsoftwarenecessarytobuildoroperatethesystem
asproposed

80. SDLC
Thenextphaseiscalleddesign.Duringthisphase,youconvertthedescriptionof
therecommendedalternativesolutionintologicalandthenphysicalsystem
specification.
Here,youmustdesignallaspectsofthesystemforminputandoutputscreensto
reports,databases,andcomputerprocesses.
Logicaldesignisthepartofthedesignprocessthatisindependentofanyspecific
hardwareorsoftwareplatform.Theoretically,thesystemcouldbeimplementedon
anyhardwareandsystemssoftware.
Physicaldesignisthepartofthedesignphaseinwhichthelogicalspecificationsof
thesystemformlogicaldesignaretransformedintotechnology-specificdetails
fromwhichallprogrammingandsystemconstructioncanbeaccomplished.

81. SDLC
Thenextphaseiscalled implementation.
Inthisphase,theinformationsystemiscoded,tested,installed,andsupportedin
theorganization.
Duringcoding,programmerswritetheprogramsthatmakeuptheinformation
system.
Duringtesting,programmersandanalyststestindividualprogramsandtheentire
systeminordertofindandcorrecterrors.
Duringinstallation,thenewsystembecomesapartofthedailyactivitiesofthe
organization.Implementationactivitiesalsoincludeinitialusersupportsuchasthe
finalizationofdocumentation,trainingprograms,andongoinguserassistance

82. SDLC
Thefinalphaseof SDLCiscalledmaintenance.
In thisphase,informationsystemis systematicallyrepairedandimproved.
Whenasystemisoperatinginanorganization,userssometimesfindproblems
with howitworksandoftenthinkof betterwaystoperformits functions.
Alsotheorganization’sneeds with respecttothesystemchangeovertime.
Inmaintenance,youmakethechangesthatusersaskforandmodifythesystemto
reflectchangingbusinessconditions.

83. SDLC

84. TraditionalWaterfallSDLC
Waterfallmodelistheoldestandthemostwidelyusedparadigmforinformation
systemsdevelopment.
Whileitdoeshaveweaknesses,itissignificantlybetterthanahaphazardapproach.
Thismodelissuitablefortheprojectsinwhichuserrequirementsarecertainand
precise.
Notehowtheflowoftheprojectbeginsintheplanningphaseandfromthereruns
“downhill”toeachsubsequentphase,justlike astream thatrunsoffacliff

85. TraditionalWaterfallSDLC
Atthecompletionofeachphase,amilestonehasbeenreachedandadocumentis
producedtobeapprovedbythestakeholdersbeforemovingtothenextphase;
painstakingamountsofdocumentationandsignoffsthrougheachpartofthe
developmentcycleisrequired.
Thepurewaterfalllifecycleconsistsofseveralnon-overlappingstages,asshownin
thefollowingfigure.
Themodelbeginswithplanning&analysisandcontinueswithlogicaldesign,
physicaldesign,implementation(i.e.coding,testing)andmaintenance.

86. TraditionalWaterfallSDLC

87. TraditionalWaterfallSDLC
Theproblemsthataresometimesencounteredwiththelinearsequentialmodel
are:
–Changescancauseconfusionastheproject teamproceeds.
–Itisoftendifficultforthecustomertostateallrequirementsexplicitly.Thelinearsequential
modelrequiresthisand makesdifficultytorespondtochangingcustomerrequirements.
–Aworkingversionofthesystem willbeavailabletocustomerslateintheprojecttime-span.
Amajor blunder,ifundetecteduntiltheworkingprogramisreviewed,can bedisastrous.
–Thelinearnatureoftheclassiclifecycleleadsto“blockingstates”inwhichsomeproject
teammembersmustwaitfor othermembersoftheteamtocompletedependenttasks.
–Userinvolvementislimited.

88. Assignment
Whencan weusewaterfallmodel?
AdvantagesanddisadvantagesofWaterfallModel.

89. Computer-AidedSystemsEngineering(CASE)

90. Computer-AidedSystemsEngineering(CASE)
Computer-aidedsystemsengineering(CASE)istheapplicationofinformation
technologytosystemsdevelopmentactivities,techniques,and methodologies.
CASEtoolsareprograms(software)thatautomateorsupportoneormorephases
of asystemsdevelopmentlifecycle.
Thetechnologyisintendedtoacceleratetheprocessofdevelopingsystemsandto
improvethequalityoftheresultingsystems.

91. CASE
CASEtoolsareclassifiedaccording towhichphasesofthelifecycletheysupport.
Thetermupper-CASEdescribestoolsthatautomateorsupportthe‘upper’phases
of systemsdevelopment–thesurvey,study,definition, and designphases.
Thetermlower-CASEdescribestoolsthatautomateorsupportthe‘lower’phases
ofsystemsdevelopment–detaileddesign,construction,andimplementation(and
alsosupport).

92. CASE
AtthecenterofanyCASEtool’sarchitectureisadeveloper’sdatabasecalleda
CASErepository.
CASErepositoryisasystemdeveloper’sdatabasewheredeveloperscanstore
systemmodels,detaileddescriptionandspecification,andotherproductsof
systemdevelopment.
Itisalsocalleddictionaryor encyclopedia.
AroundtheCASErepositoryisacollectionoftoolsorfacilitiesforcreatingsystem
modelsanddocumentation.

93. CASE
Thesefacilitiesgenerallyinclude:
Diagrammingtools–These toolsare usedtodrawsystemmodels.
Dictionarytools–Thesetoolsareusedtorecord,delete,edit,andoutput
detaileddocumentationandspecification.
Designtools–Thesetoolsareusedtoconstructsystemcomponentsincluding
systeminputsandoutputs.These are alsocalledprototypingtools.
Documentationtools–Thesetoolsareusedtoassemble,organize,andreporton
systemmodels,descriptionsandspecifications,andprototypes.
Qualitymanagementtools–Thesetoolsareusedtoanalyzesystemmodels,
descriptionsandspecifications,andprototypesforcompleteness,consistency,
andconformancetoacceptedrulesofmethodologies.
Designandcodegeneratortools–Thesetoolsautomaticallygeneratedatabase
designsand application programsor significantportionsofthoseprograms.

94. CASE

95. CASE

96. Assignment
AdvantagesanddisadvantagesofCASETools.