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8/3/2019 P5-Metodologi an SI

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INFORMATION SYSTEM

DEVELOPMENTMETHODOLOGY

Instructor: Hendrik

Course : Sistem Informasi


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Information System ReviewIS Developmnet Methodologies

- SDLC

- RAD

- XP

- Alternatives

Outline


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Kendall & Kendall2005 Pearson Prentice Hall

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Categories

Information systems fall into one of the followingeight categories:

Transaction processing systems (TPS).

Office automation systems (OAS).

Knowledge work systems (KWS).

Management information systems (MIS).

Decision support systems (DSS).

Expert systems (ES) and Artificial Intelligence (AI).

Group decision support systems (GDSS) and Computer-Supported Collaborative Work Systems.

Executive support systems (EES).


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New Technologies

New technologies are being integrated intotraditional systems:

Ecommerce uses the Web to perform businessactivities.

Enterprise Resource Planning (ERP) has the goal ofintegrating many different information systems withinthe corporation.

Wireless and handheld devices, including mobile

commerce (mcommerce).Open source software.


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Advantages of Using the Web

The benefits of using the Web are:

Increasing awareness of the availability of theservice, product, industry, person, or group.

24-hour access for users. Standard interface design.

Creating a global system.


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Nature of Analysis and Design

Systems analysis and design is a systematicapproach to:

Identifying problems, opportunities, and

objectives. Analyzing the information flows in organizations.

Designing computerized information systems tosolve a problem.


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Systems Analyst

Systems analysts act as:Outside consultants to businesses.

Supporting experts within a business.

As change agents. Analysts are problem solvers, and require

communication skills.

Analysts must be ethical with users and

customers.


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Systems Development LifeCycle

The systems development life cycle is asystematic approach to solving businessproblems.

It is divided into seven phases.

Each phase has unique activities.


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Kendall & Kendall 2005 Pearson Prentice Hall 1-9


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Phase 1

Identifying: Problems.

Opportunities.

Objectives. Personnel involved: Analyst.

User management.

Systems management.


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Phase 2

Determining information requirements:

Interview management, operations personnel.

Gather systems/operating documents.

Use questionnaires. Observe the system and personnel involved.

Learn the who, what, where, when, and how,and the why for each of these.


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Phase 2 (Continued)

Personnel involved:

Analyst.

User management.

User operations workers.

Systems management.


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Phase 3

Analyzing system needs:

Create data flow diagrams.

Document procedural logic for data flow diagram

processes. Complete the data dictionary.

Make semistructured decisions.

Prepare and present the system proposal.

Recommend the optimal solution to management.


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Phase 3 (Continued)

Personnel involved:

Analyst.

User management.

Systems management.


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Phase 4

Designing the recommended system:

Design the user interface.

Design output.

Design input.Design system controls.

Design files and/or database.

Produce program specifications.

Produce decision trees or tables.


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Phase 4 (Continued)

Personnel involved:

Analyst.

System designer.

User management.


Systems management.


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Phase 5

Developing and documenting software:Design computer programs using structure

charts, Nassi-Schneiderman charts, andpseudocode.

Walkthrough program design.

Write computer programs.

Document software with help files, proceduremanuals, and Web sites with Frequently AskedQuestions.


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Phase 5 (Continued)

Personnel involved:

Analyst.

System designer.

Programmers.

Systems management.


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Phase 6

Testing and maintaining the system:

Test and debug computer programs.

Test the computer system.

Enhance system.


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Phase 6 (Continued)

Personnel involved:

Analyst.

System designer.

Programmers.

Systems management.


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Phase 7

Implementing and evaluating the system: Plan conversion.

Train users.

Purchase and install new equipment.Convert files.

Install system.

Review and evaluate system.


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Phase 7 (Continued)

Personnel involved:

Analyst.

System designer.

Programmers.

User management.


Systems management.


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Rapid Application Development

Rapid Application development (RAD) is anobject-oriented approach to systemsdevelopment.


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System Maintenance

System maintenance is:

Removing undetected errors, and

Enhancing existing software.

Time spent on maintenance typically rangesfrom 48-60 percent of total time.


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System Enhancements

Systems are enhanced for the followingreasons:

Adding additional features to the system.

Business and governmental requirements changeover time.

Technology, hardware, and software are rapidlychanging.


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CASE Tools

CASE tools are automated, microcomputer-basedsoftware packages for systems analysis anddesign.

Four reasons for using CASE tools are: To increase analyst productivity.

Facilitate communication among analysts and users.

Providing continuity between life cycle phases.

To assess the impact of maintenance.


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CASE Tool Categories

CASE tools may be divided into severalcategoriesUpper CASE (also called front-end CASE) tools,

used to perform analysis and design.

Lower CASE (also called back-end CASE).These tools generate computer language sourcecode from CASE design.

Integrated CASE, performing both upper andlower CASE functions.


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Upper CASE

Upper CASE tools:Create and modify the system design.

Store data in a project repository.

The repository is a collection of records,elements, diagrams, screens, reports, and otherproject information.

These CASE tools model organizationalrequirements and define system boundaries.


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Lower CASE

Lower CASE tools generate computer sourcecode from the CASE design.

Source code may usually be generated in

several languages.

Ad t f G ti


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Advantages of GeneratingCode

Time to develop new systems decreases.

The time to maintain generated code is less than tomaintain traditional systems.

Computer programs may be generated in morethan one language.

CASE design may be purchased from third-partyvendors and tailored to organizational needs.

Generated code is free from program codingerrors.


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Kendall & Kendall 2005 Pearson Prentice Hall 1-31


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Reverse Engineering

Reverse engineering is generating the CASEdesign from computer program code.

Source code is examined, analyzed, and

converted into repository entities.

R E i i


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Reverse Engineering(Continued)

Reverse engineering produces (depending onthe tool set used):Data structures and elements, describing the

files, records, and field.

Screen designs, if the program is online.

Report layouts for batch programs.

A structure chart showing the hierarchy of the

modules in the program.Database design and relationships.

Ad t f R


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Advantages of ReverseEngineering

Reverse Engineering has the followingadvantages: Reduced system maintenance time.

Program documentation is produced for looselydocumented programs.

Structured programs may be generated fromunstructured, older programs.

Future system maintenance is easier to implement. Unused portions of programs may be eliminated.

Obj t O i t d A l i d


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Object-Oriented Analysis and

Design

Object-oriented (O-O) analysis and design isused to build object-oriented programs.

O-O programming examines the objects of a

system. Objects are grouped into classes for optimal

reuse and maintainability.


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The Unified Modeling Language

The Unified Modeling Language (UML) is anindustry standard for modeling object-orientedsystems.

It breaks down a system into a use casemodel.


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Extreme Programming (XP)

Extreme programming takes good softwaredevelopment practices and pushes them to thelimit.

It is based on: Values.

Principles.

Core practices.

E t P i (XP)


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Extreme Programming (XP)

(Continued)

Extreme programming values are:

Communication.

Simplicity.

Feedback.Courage.


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Alternate Methodologies

Alternate methodologies are available foranalyzing systems.

These include:

Prototyping. ETHICS.

Project Champions.

Soft Systems Methodology.

Multi-view.

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