Pertemuan 5

Pengembangan Teknologi Informasi

Matakuliah : H0402/PENGELOLAAN SISTEM KOMPUTER

Tahun : 2005

Versi : 1/0

Learning Outcomes

Pada akhir pertemuan ini, diharapkan mahasiswa

akan mampu :

• Menunjukkan metodologi pengembangan Teknologi Informasi pada dunia nyata

Outline Materi

• System Development Life Cycle

• Prototyping

• JAD

• CASE

• RAD

• Object-Oriented

SYSTEMS DEVELOPMENT LIFE CYCLE (SDLC)

• DEFINITION PHASE: – Feasibility analysis– Requirement definition

• CONSTRUCTION PHASE:– System design– System building– System testing

• IMPLEMENTATION PHASE:– Installation– Operations– Maintenance

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DEFINITION PHASE

• FEASIBILITY ANALYSIS: Thorough analysis by team (leader, systems analysts, end-users). Economic, operational, technical

• REQUIREMENTS DEFINITION: If feasibility report approved, team develops logical design: processes, data flow & relationships. Result is system requirements document

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CONSTRUCTION PHASE

• SYSTEM DESIGN: Detailed design of physical system based on requirements document. Details of hardware, software, databases, modules, interrelationships for quality system (accurate, reliable, auditable, robust, changeable, secure, efficient, user friendly, flexible, well documented)

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CONSTRUCTION PHASE

• SYSTEM BUILDING: IS specialists produce programs, databases. End-users answer questions, interpret requirements, help design documents

• SYSTEM TESTING: By module, subsystem, entire system to find & correct problems. Users acceptance test

• DOCUMENTATION

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IMPLEMENTATION PHASE

• INSTALLATION: Four strategies– Parallel: Run old & new systems for awhile to check

validity. Safe– Pilot: Install in one part of organization at a time.

Learn and adapt– Phased: In large system change one function at a

time (e.g., order entry)– Cutover: Start using entire system. Can be dangerous

if errors exist

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IMPLEMENTATION PHASE

• OPERATIONS: Training, documentation, people and computers must work well together. Project team disbanded

• MAINTENANCE: Operations stage of life cycle. Correct errors as discovered, update as needed, monitor activities and output. Be aware of gap between organization’s needs and system’s performance

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COST OF ERROR CORRECTION

3.51 10 2050

150

0

50

100

150

200

1 2 3 4 5 6

PHASE IN WHICH ERROR DETECTED

RE

LA

TIV

E C

OS

T T

O

FIX

ER

RO

R

1. REQUIREMENTS 4. DEVELOPMENT TEST

2. DESIGN 5. ACCEPTANCE TEST

3. CODE 6. OPERATION

SDLC ROLES

• PROJECT MANAGER: Must have IS skills, plans project, uses project management tools, builds project team

• SYSTEMS ANALYST: IS professional changes business problem into IS solution

• END-USER: Functional representative provides needs, judges results

• SPONSORS, CHAMPIONS: Will be addressed in Chapter 12

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SDLC CHARACTERISTICS

• MANAGEABLE PROJECT SIZE: Break into independent pieces. Stay within budget & other constraints

• ACCURATE REQUIREMENTS DEFINITION: Extraneous specifications lead to added expense, extends completion

• EXECUTIVE SPONSORSHIP: Sponsor with responsibility and resources critical to success

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SDLC ADVANTAGES

• HIGHLY STRUCTURED, SYSTEMATIC PROCESS

• THOROUGH DEFINITION REQUIREMENTS

• CLEAR MILESTONES WITH MANAGEMENT SIGN-OFFS

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SDLC DISADVANTAGES

• MAY IGNORE EVOLVING REQUIREMENTS DURING PROJECT

• TIME-CONSUMING, COSTLY PROCESS

• TOP-DOWN COMMITMENT REQUIRED

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PROTOTYPING LIFE CYCLE

1. IDENTIFY REQUIREMENTS

2. DEVELOP INITIAL PROTOTYPE

3. USE PROTOTYPE, NOTE CHANGES

4. REVISE, ENHANCE PROTOTYPE: Return to Step 3 as needed

5. EVALUATE OPERATIONAL SYSTEM

6. MAKE CHANGES OR ABANDON

7. INSTALL, OPERATE, MAINTAIN

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COMBINING PROTOTYPING & SDLC

• PROTOTYPING/PILOTING PHASE:– DETERMINE BASIC REQUIREMENTS

– PROTOTYPE SYSTEM

– PILOT PROTOTYPE

• SDLC CONSTRUCTION PHASE: – SYSTEM BUILDING

– SYSTEM TESTING

• SDLC IMPLEMENTATION PHASE:– INSTALLATION

– OPERATIONS

– MAINTENANCE

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JOINT APPLICATION DESIGN (JAD)

• TECHNIQUE INVOLVING TEAM OF USERS, IS SPECIALISTS

• INTENSE, STRUCTURED PROCESS

• DEVELOP REQUIREMENTS OR REVIEW DESIGN PROPOSAL

• CAN LAST HOURS, DAYS, OFTEN AT LOCATION REMOVED FROM WORKPLACE

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COMPUTER-AIDED SOFTWARE ENGINEERING (CASE)

COLLECTION OF SOFTWARE TOOLS TO AUTOMATE SDLC PROCESSES:

• DIAGRAMMING TOOLS• COMPUTER DISPLAY, REPORT GENERATORS• ANALYSIS TOOLS• CENTRAL REPOSITORY• DOCUMENTATION GENERATORS• CODE GENERATORS

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RAPID APPLICATION DEVELOPMENT (RAD)

• HYBRID OF SDLC, PROTOTYPING, JAD, CASE

• PRODUCE SYSTEM IN 6 MONTHS OR LESS

• STEPS:– PLANNING – USER DESIGN – CONSTRUCTION– IMPLEMENTATION (CUTOVER)

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RAD ADVANTAGES

• DRAMATIC SAVING IN TIME

• FOCUSES ON ESSENTIAL SYSTEM REQUIREMENTS

• ABILITY RAPIDLY TO CHANGE SYSTEM DESIGN AT USER’S REQUEST

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RAD DISADVANTAGES

• QUALITY MAY BE SACRIFICED FOR SPEED

• TIME CONSUMING FOR KEY PERSONNEL

• POSSIBLE SHORTCUTS ON INTERNAL STANDARDS, MODULE REUSABILITY

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OBJECT-ORIENTED METHODS (O-O)

• HOLD GREAT PROMISE TO PRODUCE BETTER SYSTEMS AT LESS COST

• OBJECTS HIGHLY COHESIVE, LOOSELY COUPLED, REUSABLE

• CAN REDUCE ERRORS, IMPROVE MAINTENANCE

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• System Development Life Cycle

• Prototyping

• JAD

• CASE

• RAD

• Object-Oriented

Pengembangan Teknologi Informasi