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Pertemuan 08System Development: System life cycle

methodologies

Matakuliah : M0084/Sistem Informasi dalam ManajemenTahun : 2005Versi : 1/1

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Learning Outcomes

Pada akhir pertemuan ini, diharapkan mahasiswa akan mampu :• Mahasiswa dapat Menerangkan tahap

dalam pengembangan sisfo perusahaan (C2)

• Mahasiswa dapat Memilih metode pengembangan sisfo untuk suatu perusahaan (C4)

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Outline Materi

• The Traditional SDLC• Tahapan siklus hidup sistem• Personil yang terlibat• Manajemen siklus hidup• Keuntungan sentralisasi• Susunan manajer• Tahap pembangunan

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THE SYSTEMS DEVELOPMENT LIFE CYCLE

• The system life development cycle (SDLC) is an application of the systems approach methodology to the development of an information system

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THE TRADITIONAL SDLC• It didn’t take the first system developers long to

recognize a sequence if the project was to have the best chance of success:

• Planning• Analysis• Design• Implementation• Use

• Figure 7.4 illustrates how the life cycle phases can fit into a circular pattern over time

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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 control

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StepsSteps

1. Recognize problem (the trigger)1. Recognize problem (the trigger)2. Define problem 2. Define problem 3. Set objectives3. Set objectives4. Identify constraints4. Identify constraints

Recall that objectives, standards, and constraints are problem-solving elements.

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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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Steps (cont.)Steps (cont.)

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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Steps (cont.)Steps (cont.)

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 system study proposal

Establish a control mechanism

Approve or disapprove the study project

Recognize the problem

Set system objectives

Identify systemconstraints

The Planning PhaseThe Planning PhaseMIS Steering Comm Manager Systems AnalystMIS Steering Comm Manager Systems Analyst

1.1.

2.2.

3.3.

4.4.

5.

6.

7.7.

8.8.

Conduct a feasibility study

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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 team Organize 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) ObservationObservation Record search (includes review of existing Record search (includes review of existing

documentation)documentation) SurveysSurveys

A project directory can be maintained as an encompassing set of documentation to describe the system

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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 design Approve 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 Steering MIS Steering CommitteeCommittee ManagerManager Systems AnalystSystems Analyst

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Approve or disapprove the system Approve or disapprove the system implementationimplementation

Prepare the Prepare the detailed detailed design design systemsystem

Identify Identify alternate alternate system system

configurationsconfigurations

Evaluate Evaluate system system

configurationsconfigurations

Select the Select the best best

configurationconfiguration

Prepare the Prepare the implementation implementation

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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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 system 6. Approve or disapprove the system

implementationimplementation

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Implementation PhaseImplementation Phase

Acquire and integrate the physical and Acquire and integrate the physical and conceptual resources to produce a conceptual resources to produce a working systemworking system

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Steps for the Implementation Steps for the Implementation PhasePhase

1. Plan implementation1. Plan implementation2. Announce2. Announce3. Obtain hardware resources3. Obtain hardware resources

RFPRFP / Written Proposals/ Written Proposals4. Obtain software resources4. Obtain software resources

"Make or buy""Make or buy"5. Prepare database5. Prepare database6. Prepare physical facilities6. Prepare physical facilities7. Educate participants and users7. Educate participants and users8. Prepare cutover proposal8. Prepare cutover proposal9. Approve or disapprove cutover to new systsem 9. Approve or disapprove cutover to new systsem 10. Cutover to new system10. 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

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

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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 Phase 1.1.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 the project By internal auditor (a different one from the project

team member)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 The Use PhasePhase

Control Use thesystem

Audit thesystem

Maintain the

system

Preparere-

engineeringproposal

Approve or disapprove thereengineering proposal

MIS Steering Committee Manager Information Specialists

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4

5

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PROTOTYPING• A prototype is a version of a potential system that

provides the developers and potential users with an idea of how the system will function when completed

• In prototyping, a prototype is produced as quickly as possible, perhaps overnight, to obtain user feedback that will enable the prototype to be improved

• Figure 7.5 shows the four steps involved in developing an evolutionary prototype

• Figure 7.6 shows the steps involved in developing a requirements prototype

• As prototyping has proven to be one of the most successful methodologies, it would be difficult to find a development project that didn’t use it to some degree

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RAPID APPLICATION DEVELOPMENT

• Rapid Application Development (RAD), is a term coined by James Martin. It refers to a development life cycle intended to produce systems quickly without sacrificing quality

• Information engineering is the name that Martin gave to his overall approach to system development, which treats it as a firm-wide activity, while the term enterprise is used to describe the entire firm

• Figure 7.7 illustrates the top-down nature of information engineering, involving both data (the left face of the pyramid) and activities (the right face)

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RAD (cont.)• RAD requires four essential ingredients:

• Management • People • Methodologies • Tools

• Of all the components of information engineering, RAD has probably enjoyed the greatest support

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PHASED DEVELOPMENT• This is an approach for developing information

systems that consists of six stages: 1. Preliminary investigation2. Analysis 3. Design 4. Preliminary construction5. Final construction6. System test and installation

• The analysis, design, and preliminary construction stages are taken for each system module

• The six phased development stages are illustrated in Figure 7.8

• Figure 7.9 illustrates how the module phases are integrated into the system development

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PROJECT MANAGEMENT• Today, it is possible for life cycle

management to span several organizational levels and involve managers outside of IT

• Figure 7.16 shows the hierarchical nature of project management

• In this example, there are five development projects going at the same time, all managed by the MIS steering committee

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The MIS Steering Committee • The MIS Steering Committee performs

three main functions:– It establishes policies that ensure computer

support for achieving the strategic objectives of the firm

– It provides fiscal control by serving as the approval authority for all requests for computer-related funds

– It resolves conflicts that arise concerning priorities for computer use

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Project Leadership • A project team includes all of the

persons who participate in the development of an information system

• A team might have as many as a dozen members, consisting of some combination of users, information specialists, and may include an internal auditor

• A team or project leader, who provides direction throughout the life of the project, directs the team activity

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The Project Management Mechanism

• The basis for project management is the project plan • A popular format for a detailed plan is a Gantt chart,

which identifies the tasks, who will perform them, and when they will be performed

• A Gantt chart is a horizontal bar chart that includes a bar for each task to be performed arranged in a time sequence

• Figure 7.17 is the first part of a Gantt chart, prepared using a Microsoft Excel spreadsheet

• A complement to the Gantt chart is the network diagram. Figure 7.18 is a high-level network diagram that identifies the phases of a project

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End of Session 8