MANAGEMENT INFORMATION SYSTEMS 8/E Raymond...

Chapter 7System Life CycleSystem Life Cycle

MethodologiesMethodologies

MANAGEMENT INFORMATION SYSTEMS 8/ERaymond McLeod, Jr. and George Schell

Copyright 2001 Prentice-Hall, Inc.7-1

OBJECTIVESOBJECTIVES

Realize that the development and use of aRealize that the development and use of acomputer-based system progresses through a lifecomputer-based system progresses through a lifecycle, and that users and information specialistscycle, and that users and information specialistsplay key roles in each phaseplay key roles in each phaseBe aware of the MIS steering committee, theBe aware of the MIS steering committee, thefunctions that it performs, and the advantages thatfunctions that it performs, and the advantages thataccrue from its participation in the life cycleaccrue from its participation in the life cycleKnow the benefits that can be expected fromKnow the benefits that can be expected fromplanning the system life cycleplanning the system life cycle

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The Systems Life Cycle (SLC)The Systems Life Cycle (SLC)

MethodologyMethodology–– Recommended way of doing somethingRecommended way of doing something

An application of the systems approachAn application of the systems approachto the task of developing and using ato the task of developing and using acomputer-based systemcomputer-based systemOften called waterfall approachOften called waterfall approach

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Phases in the SDLCPhases in the SDLC

1) Planning1) Planning2) Analysis2) Analysis3) Design3) Design4) Implementation4) Implementation5) Use5) Use

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The System Development LifeThe System Development LifeCycle (SDLC)Cycle (SDLC)

SDLC is the phrase that encompasses the planning,SDLC is the phrase that encompasses the planning,analysis, design, and implementation phases of the systemanalysis, design, and implementation phases of the systemlife cyclelife cycleWho participatesWho participates–– IS personnelIS personnel–– UserUser–– Information specialists can consultInformation specialists can consult

TraditionalTraditional–– Information specialists working with users.Information specialists working with users.–– A new strategy: OutsourcingA new strategy: Outsourcing

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Life Cycle ManagementLife Cycle Management

An upward migrationAn upward migrationExecutive responsibilityExecutive responsibilityMIS steering committeeMIS steering committee–– FunctionsFunctions

»» Set policySet policy»» Control the purse stringsControl the purse strings»» Resolve conflictsResolve conflicts

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Executives

MIS SteeringCommittee

Project leader -Warehouselocation model team

Project leaderMRP 11 team

Project leaderISDN system team

Project leader HRIS team

Marketing

Manufacturing

Finance

HumanResources

Project leaderCredit approvalsystem team

Managers of Systems Life Cycles are Arranged in a HierarchyManagers of Systems Life Cycles are Arranged in a Hierarchy

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Main Advantages ofMain Advantages ofthe Steering Committeethe Steering Committee

Total firm supportTotal firm supportProjects will be characterized by goodProjects will be characterized by goodplanning and controlplanning and controlEstablishes policies, provides fiscal control,Establishes policies, provides fiscal control,and resolves conflictsand resolves conflicts

Since the steering committee will probably not getinvolved with the details of the work, a projectteam is usually appointed.

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Planning PhasePlanning Phase

BenefitsBenefits–– Define scope of the projectDefine scope of the project

–– Spot potential problemsSpot potential problems

–– Arrange tasks in sequenceArrange tasks in sequence

–– Provide basis for controlProvide basis for control7-9

StepsSteps

1. Recognize problem (the trigger)1. Recognize problem (the trigger)2. Define problem2. Define problem3. Set objectives3. Set objectives4. Identify constraints4. Identify constraints

Recall that objectives, standards,and constraints are problem-solvingelements.

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Steps (cont.)Steps (cont.)

5.5. Conduct feasibility study (TENLOS)Conduct feasibility study (TENLOS)–– TechnicalTechnical–– Economic returnEconomic return–– Noneconomic returnNoneconomic return–– Legal and ethicalLegal and ethical–– OperationalOperational–– ScheduleSchedule

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6.6. Prepare study project proposalPrepare study project proposal–– Goes to MIS steering committeeGoes to MIS steering committee

7.7. Approve or disapprove (go/no go)Approve or disapprove (go/no go)–– Key questions?Key questions?1.1.Will the system accomplish its goals?Will the system accomplish its goals?2.2.Is this the best way to go about it?Is this the best way to go about it?

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8.8. Establish a control mechanismEstablish a control mechanism–– Think in terms of:Think in terms of:

»» 1. What1. What»» 2. Who2. Who»» 3. When (Person-months versus calendar months)3. When (Person-months versus calendar months)

–– PERT and CPM network diagramsPERT and CPM network diagrams

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Define theproblem

ConsultConsult

Prepare a systemstudy proposal

Establish a control mechanism

Approve or disapprove the study project

Recognize the problem

Set systemobjectives

Identify systemconstraints

The Planning PhaseThe Planning PhaseMIS SteeringMIS Steering Comm Comm Manager Systems AnalystManager Systems Analyst

1.1.

2.2.

3.3.

4.4.

5.

6.

7.7.

8.8.

Conduct afeasibility study

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Outline of a System Study ProposalOutline of a System Study Proposal1. Executive summary2. Introduction3. System objectives and constraints4. Possible system alternatives5. The recommended system study project

5.1 Tasks to be performed5.2 Human resource requirements5.3 Schedule of work5.4 Estimated cost

6. Expected impact of the system6.1 Impact on the firm’s organization structure6.2 Impact on the firm’s operations6.3 Impact on the firms resources

7. General development plan (analysis, design, and implementation phase)8. Summary

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A Project ScheduleA Project ScheduleFunctional System:Functional System: MarketingMarketingSubsystem:Subsystem: ProductProductModel:Model: Product DeletionProduct Deletion

SubtaskSubtaskTimeTime

EstimateEstimate(Person Months)(Person Months)

ResponsibilityResponsibility

1. Identify1. Identifydeletion criteriadeletion criteria

2. Identify output2. Identify outputinformationinformationrequirementsrequirements

Systems analystSystems analystProduct managerProduct manager

Systems analystSystems analystNetwork specialistNetwork specialistProduct managerProduct manager

0.750.75

0.250.257-16

Project Schedule (cont.)Project Schedule (cont.)

3. Identify input data Systems analyst 0.503. Identify input data Systems analyst 0.50 requirements DBA requirements DBA4. Prepare new system Systems analyst 2.004. Prepare new system Systems analyst 2.00 documentation documentation5. Design network Network specialist 1.505. Design network Network specialist 1.506. Design database DBA 0.506. Design database DBA 0.507. Review design Product manager 0.257. Review design Product manager 0.25 Systems analyst Systems analyst8. Prepare program Programmer 1.008. Prepare program Programmer 1.00 documentation documentation

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Project Schedule (cont.)Project Schedule (cont.)

9. Code program Programmer 1.259. Code program Programmer 1.2510. Test program Programmer 0.7510. Test program Programmer 0.75 Operations staff Operations staff11. Approve program Product manager 0.5011. Approve program Product manager 0.50 VP of marketing VP of marketing12. Prepare database DBA 2.0012. Prepare database DBA 2.0013. Educate users Systems analyst 0.5013. Educate users Systems analyst 0.5014. Cutover to model Operations staff 0.7514. Cutover to model Operations staff 0.75

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Analysis PhaseAnalysis Phase

StepsSteps1.1.AnnounceAnnounce

»» Reasons for projectReasons for project»» Purpose: inform and counteract fearPurpose: inform and counteract fear

2.2.Organize project teamOrganize project team»» User(s)User(s)»» SpecialistsSpecialists»» Define rolesDefine roles

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Analysis Phase (cont.)Analysis Phase (cont.)

3.3. Define information needsDefine information needs»» MethodsMethods

Personal interview (the preferred method)Personal interview (the preferred method)ObservationObservationRecord search (includes review of existingRecord search (includes review of existingdocumentation)documentation)SurveysSurveys

A project directory can bemaintained as an encompassing setof documentation to describe thesystem

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Analysis Phase (cont.)Analysis Phase (cont.)

4.4. Define system performance criteriaDefine system performance criteria5.5. Prepare design proposalPrepare design proposal(Compare to system study proposal)(Compare to system study proposal)6.6. Approve or disapprove the designApprove or disapprove the design

projectproject

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Announce the system study

Organize the project team

Define information needs

Define system performance criteria

Preparedesign

proposal

Approve or disapprove the design project

1.

2.

3.

4.

5.

6.

The Analysis PhaseThe Analysis PhaseMIS SteeringMIS SteeringCommitteeCommittee ManagerManager Systems AnalystSystems Analyst

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Outline of a Design ProposalOutline of a Design Proposal1. Executive summary2. Introduction3. Problem definition4. System objectives and constraints5. Performance criteria6. Possible system alternatives7. The recommended design project

7.1 Tasks to be performed7.2 Human resource requirements7.3 Schedule of work7.4 Estimated cost


9. General development plan (analysis, design, and implementation)10. Summary

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Approve or disapprove the systemApprove or disapprove the systemimplementationimplementation

Prepare thePrepare thedetaileddetaileddesigndesignsystemsystem

IdentifyIdentifyalternatealternatesystemsystem

configurationsconfigurations

EvaluateEvaluatesystemsystem

configurationsconfigurations

Select theSelect thebestbest

configurationconfiguration

Prepare thePrepare theimplementationimplementation

proposalproposal

1.1.

2.2.

3.3.

4.4.

5.5.

6.

MIS Steering CommitteeMIS Steering Committee ManagerManager Systems AnalystSystems Analyst

The Design PhaseThe Design Phase

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Design PhaseDesign Phase

1.1. Prepare detailed designPrepare detailed design–– Structured design (top down)Structured design (top down)

»» System levelSystem level»» Subsystem levelSubsystem level

–– Documentation toolsDocumentation tools

2. Identify alternate system configurations2. Identify alternate system configurations–– Refine to a manageable setRefine to a manageable set

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Popular Documentation ToolsPopular Documentation Tools

Data Modeling Entity-relationship diagramData dictionaryScreen/printer layout form

Process Modeling System flowchartProgram flowchartData flow diagramStructured English

Object Modeling Object relationship modelClass specification

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Data Flow Diagram of Four Data Processing SubsystemsData Flow Diagram of Four Data Processing Subsystems

Customers

1.4Accounts

Receivable

1.1OrderEntry

1.3Billing

1.2Inventory

Sales orders

Rejected salesorder notices

Accepted orders

Payments bycustomers

Stat

emen

ts

Invoices

Billed orders

Receivables ledger data

Order logremovals file

Filled items

Inventoryledger data

Received items

Purchasing data

3

3 2

2

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Data Flow Diagram of Order Entry SystemData Flow Diagram of Order Entry SystemSales orderedit rejects

Order log

Sales ordercredit rejects

Customercredit file

Customer

1.1.1Edit

orderdata

1.1.2Compute

creditcheck

1.1.3Log inorders

1.1.4Markfilled

orders

1.2

1.3

Sales orders Edit rejects

Rejectedsales ordernotices

Edited orders

Credit data

Edited and checked orders

Credit rejects

Acceptedorders

Completed orders Date filled

Order data

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Hardware Choices Make PossibleHardware Choices Make PossibleMultiple System ConfigurationsMultiple System Configurations

System ElementsSystem Elements AlternativesAlternatives••CRT terminalCRT terminal••Hardcopy terminalHardcopy terminal••OCROCR

Input

Order log

Customer credit file

Rejected orders file

Accepted orders file

Completed orders file

Rejected orders notice

Processing

••Magnetic tapeMagnetic tape••DASDDASD





••PrinterPrinter••CRT terminalCRT terminal••Hardcopy terminalHardcopy terminal••BatchBatch

••OnlineOnline

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Alternatives Selected for Detailed StudyAlternatives Selected for Detailed StudyAlternativeAlternative

InputInputOrderOrderLogLog

CustomerCustomerCredit FileCredit File

Accepted &Accepted &RejectedRejected

Orders FileOrders File

CompletedCompletedOrders FileOrders File

RejectedRejectedOrdersOrdersNoticeNotice

1.1.

2.2.

3.3.

ScannerScanner

KeyboardKeyboardterminalterminal

MagneticMagnetictapetape

KeyboardKeyboardterminalterminal












PrinterPrinter

PrinterPrinter

HardcopyHardcopyterminalterminal

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Design Phase (cont.)Design Phase (cont.)

3. Evaluate configurations3. Evaluate configurations4. Select best configuration4. Select best configuration5. Prepare implementation proposal5. Prepare implementation proposal6. Approve or disapprove the system6. Approve or disapprove the system

implementationimplementation

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1. Executive summary2. Introduction3. Problem definition4. System objectives and constraints5. Performance criteria6. System design

6.1 Summary description6.2 Equipment configuration

7. The recommended implementation project7.1 Tasks to be performed7.2 Human resource requirements7.3 Schedule of work7.4 Estimated cost


9. General implementation plan10. Summary

Outline of an Implementation ProposalOutline of an Implementation Proposal

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Implementation PhaseImplementation Phase

Acquire and integrate the physical andAcquire and integrate the physical andconceptual resources to produce aconceptual resources to produce aworking systemworking system

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Steps for the Implementation PhaseSteps for the Implementation Phase1. Plan implementation2. Announce3. Obtain hardware resources

RFP / Written Proposals4. Obtain software resources

"Make or buy"5. Prepare database6. Prepare physical facilities7. Educate participants and users8. Prepare cutover proposal9. Approve or disapprove cutover to new systsem10. Cutover to new system

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Plan the implementation

Announce the implementation

Control

Cutover the new system

Obtain the hardware resources

Obtain the softwareresources

Prepare the database

Educate the participants and users

Prepare the physical facilities

Control

1.1.

2.2.33

44

55

66

77

8.

The Implementation PhaseThe Implementation PhaseMIS Steering CommitteeMIS Steering Committee ManagerManager Information SpecialistsInformation Specialists

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Outline of a Request for ProposalOutline of a Request for Proposal

1. Letter of transmittal2. System objective and applicable constraints3. System design

3.1 Summary description3.2 Performance criteria3.3 Equipment configuration3.4 Summary system documentation3.5 Estimated transaction volume3.6 Estimated file size

4. Installation schedule

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Outline of Supplier ProposalOutline of Supplier Proposal

1. Letter of transmittal2. Summary of recommendations3. Advantages4. Equipment configuration5. Equipment specifications

5.1 Performance data5.2 Prices

6. Satisfaction and performance criteria7. Delivery schedule

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Cutover ApproachesCutover Approaches

Old System

Old System New System

Immediate cutoverPhased cutover

Parallel cutover

Pilot System

Immediate

Old SystemNew SystemPhased

New system

Old SystemParallel

Time

Pilot

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Use PhaseUse Phase1.1.UseUse2.2.Audit (post implementation review)Audit (post implementation review)

»» By information specialist(s)By information specialist(s)»» By internal auditor (a different one from theBy internal auditor (a different one from the

project team member)project team member)

3. Maintain the system3. Maintain the system»» Correct errorsCorrect errors»» Keep currentKeep current»» ImproveImprove

4. Prepare reengineering proposal4. Prepare reengineering proposal5. Approve or disapprove reengineering5. Approve or disapprove reengineering

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The Use PhaseThe Use Phase

Control Use thesystem

Audit thesystem

Maintain the

system

Preparere-

engineeringproposal

Approve or disapprove thereengineering proposal

MIS Steering Committee Manager Information Specialists

12

3

4

5

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PrototypingPrototyping

Type I -- Becomes operational systemType I -- Becomes operational system

Type II -- Serves as a blueprintType II -- Serves as a blueprint

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Development of a Type I PrototypeDevelopment of a Type I Prototype

1.1.

2.2.

3.3.

4.4.

NN

Identify user needsIdentify user needs

Develop a prototypeDevelop a prototype

PrototypePrototypeacceptable?acceptable?

YY

Use the prototypeUse the prototype

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DevelopmentDevelopmentof a Type IIof a Type IIPrototypePrototype NN

NN

Identify userIdentify userneedsneeds

Develop aDevelop aprototypeprototype

Code theCode theoperational systemoperational system

Test theTest theoperational systemoperational system

Use theUse theoperational systemoperational system

PrototypePrototypeacceptable?acceptable?

SystemSystemacceptable?acceptable?

YY

YY

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The Attraction of PrototypingThe Attraction of PrototypingCommunications between the systemsCommunications between the systemsanalyst and user are improved.analyst and user are improved.The analyst can do a better job ofThe analyst can do a better job ofdetermining the user’s needs.determining the user’s needs.The user plays a more active role in systemThe user plays a more active role in systemdevelopment.development.The information specialists and the userThe information specialists and the userspend less time and effort in developing thespend less time and effort in developing thesystem.system.Implementation is much easier because theImplementation is much easier because theuser knows what to expect.user knows what to expect. 7-44

Potential Pitfalls of PrototypingPotential Pitfalls of PrototypingThe haste to deliver the prototype mayThe haste to deliver the prototype mayproduce shortcuts in problem definition,produce shortcuts in problem definition,alternative evaluation, and documentation.alternative evaluation, and documentation.The users may get so exited about theThe users may get so exited about theprototype that they have unrealisticprototype that they have unrealisticexpectations of the operational system.expectations of the operational system.Type I prototypes might not be as efficientType I prototypes might not be as efficientas systems coded in a programmingas systems coded in a programminglanguage.language.The computer-human interface provided byThe computer-human interface provided bycertain prototyping tools may not reflectcertain prototyping tools may not reflectgood design techniques.good design techniques. 7-45

Applications That Are GoodApplications That Are GoodProspects for PrototypingProspects for PrototypingHigh riskHigh riskConsiderable user interactionConsiderable user interactionLarge number of usersLarge number of usersA need for quick deliveryA need for quick deliveryAn expected short use phase of theAn expected short use phase of thesystemsystemAn innovative systemAn innovative systemUnpredictable user behaviorUnpredictable user behavior

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Rapid Application Development (RAD)Rapid Application Development (RAD)

Information engineering (IE)Information engineering (IE)Key ingredientsKey ingredients–– Management should be experimenters orManagement should be experimenters or

early adaptersearly adapters–– Specialized teamsSpecialized teams–– Methodologies (RAD life cycle)Methodologies (RAD life cycle)–– Tools (I-CASE, 4GLs)Tools (I-CASE, 4GLs)

RAD and the SLC are applications of theRAD and the SLC are applications of thesystems approachsystems approachTools are mainly 4th generation languages andTools are mainly 4th generation languages andCASE toolsCASE tools 7-47

Informationstrategyplanning

(ISP)Business area

analysis(BAA)

Rapid application development(RAD)

.

Strategic overview of theinformation needed to runan enterprise as efficientlyas possible

Data model

Design of records used by specificprocedures

Strategic overview of thefunctions and goals ofan enterprise

The process needed tooperate the enterpriseand how they interrelate

Design ofprocedures forspecific applications

Rapid Application Development is an Integral Part of Information Engineering

DataActivities

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Business Process RedesignBusiness Process Redesign(BPR)(BPR)

Often used to react to systems that can noOften used to react to systems that can nolonger function adequately in the currentlonger function adequately in the currentbusiness environment of the firm (legacybusiness environment of the firm (legacysystems fall into this category)systems fall into this category)Three techniques for business processThree techniques for business processredesign areredesign are1) reverse engineering1) reverse engineering2) restructuring2) restructuring3) reengineering3) reengineering 7-49

Reverse EngineeringReverse EngineeringReverse Engineering Produces Documentation onReverse Engineering Produces Documentation onSuccessively Higher Levels but Leaves the SystemSuccessively Higher Levels but Leaves the System

UnchangedUnchanged

ReverseReverseEngineeringEngineering EngineeringEngineering

ReverseReverseEngineeringEngineeringReverseReverse

EngineeringEngineeringReverseReverse

Planning Planning PhasePhase

Analysis Analysis PhasePhase

Design Design PhasePhase

ImplementationImplementationPhasePhase

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RestructuringRestructuring

PlanningPhase

Restructuring Restructuring Restructuring Restructuring

AnalysisPhase

DesignPhase

ImplementationPhase

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ReengineeringReengineeringReverseEngineering

ReverseEngineering

ReverseEngineering

ReverseEngineering

ForwardEngineering

ForwardEngineering

ForwardEngineering

ForwardEngineering

Planning Phase

Analysis Phase

DesignPhase

ImplementationPhase

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Selection of BPR ComponentsSelection of BPR Components

Based upon functional qualityBased upon functional quality–– What the system doesWhat the system does

Based upon technical qualityBased upon technical quality–– How the system does its jobHow the system does its job

The relationship between these twoThe relationship between these twocharacteristics suggest which BPRcharacteristics suggest which BPRtechnique would be appropriatetechnique would be appropriate

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FunctionalQuality(What?)

Good

Technical Quality(How?)

Poor

Poor

Good

Selection of BPR Components

Reverse Engineer

Restructure

Do Nothing

ForwardEngineer

Reengineer

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SLC, Prototyping, RAD, and BPR inSLC, Prototyping, RAD, and BPR inPerspectivePerspective

SLC, prototyping, and RAD are allSLC, prototyping, and RAD are allmethodologiesmethodologies–– Recommended ways of implementing aRecommended ways of implementing a

computer-based systemcomputer-based system

BPR revamps systems that wereBPR revamps systems that wereimplemented with computer technology thatimplemented with computer technology thathas become obsoletehas become obsolete

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SummarySummary

System Life CycleSystem Life Cycle–– PlanningPlanning–– AnalysisAnalysis–– DesignDesign–– ImplementationImplementation–– UseUse

Cycle management responsibilityCycle management responsibilityOther methodologiesOther methodologies

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