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Chapter 1

The Systems DevelopmentEnvironment

Modern Systems Analysisand Design

Fifth Edition

Jeffrey A. HofferJoey F. George

Joseph S. Valacich

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2008 by Prentice Hall 3Chapter 1

Introduction

Information Systems Analysis and Design

Complex organizational process.

Used to develop and maintain computer-based information systems.

Used by a team of business and systemsprofessionals.

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Introduction (Cont.)


Figure 1-1 An organizational approach to systems analysis and

design is driven by methodologies, techniques, and tools

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A Modern Approach to Systems

Analysis and Design (Cont.)Application Software

Computer software designed to support

organizational functions or processes.

Systems Analyst role

Study the problems and needs of an

organization to bring improvements to theorganization

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Types of Information Systems

and Systems Development Transaction Processing Systems (TPS)

Automate handling of data about business

activities (transactions)Process orientation

Management Information Systems (MIS)

Converts raw data from transactionprocessing system into meaningful form

Data orientation

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Types of Information Systems

and Systems Development (Cont.) Decision Support Systems (DSS)

Designed to help decision makers

Provides interactive environment for decisionmaking

Involves data warehouses, executive

information systems (EIS)Database, model base, user dialogue

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Summary of Information

Systems Types

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Developing Information Systems

System Development Methodology is astandard process followed in an

organization to conduct all the stepsnecessary to analyze, design, implement,

and maintain information systems.

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Systems Development Life

Cycle (SDLC) Traditional methodology used to develop,

maintain, and replace information systems.

Phases in SDLC: Planning

Analysis

Design

Implementation

Maintenance

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Systems Development Life Cycle

(SDLC) (Cont.) Planningan organizations total

information system needs are identified,

analyzed, prioritized, and arranged. Analysis system requirements are

studied and structured.

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(SDLC) (Cont.) Design a description of the

recommended solution is converted into

logical and then physical systemspecifications.

Logical design all functional features ofthe system chosen for development inanalysis are described independently ofany computer platform.

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(SDLC) (Cont.) Physical design the logical

specifications of the system from logical

design are transformed into thetechnology-specific details from which all

programming and system construction can

be accomplished.

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(SDLC) (Cont.) Implementation the information system

is coded, tested, installed and supported in

the organization. Maintenance an information system is

systematically repaired and improved.

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Traditional Waterfall SDLC

One phase begins

when anothercompletes, little

backtracking and

looping

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Problems with Waterfall Approach

System requirements locked in after

being determined (can't change).

Limited user involvement (only inrequirements phase).

Too much focus on milestone deadlines of

SDLC phases to the detriment of sounddevelopment practices.

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Different Approaches to Improving

Development Prototyping

Computer-Aided Software Engineering (CASE)

Tools Joint Application Design (JAD)

Rapid Application Development (RAD)

Agile Methodologies eXtreme Programming

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Prototyping

Iterative development process:

Requirements quickly converted to a

working system.

System is continually revised.

Close collaboration between users and

analysts.

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Prototyping (Cont.)

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Computer-Aided Software Engineering

(CASE) Tools

Software tools that provide automated support for someportion of the systems development process.

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(CASE) Tools (general types)

Diagramming tools enable graphical representation.

Computer displays and report generators helpprototype how systems look and feel.

Analysis tools automatically check for consistencyin diagrams, forms, and reports.

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(CASE) Tools (general types) Central repository for integrated storage of

diagrams, reports, and project managementspecifications.

Documentation generators standardize technicaland user documentation.

Code generators enable automatic generation ofprograms and database code directly from designdocuments, diagrams, forms, and reports.

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CASE Tools (Cont.)


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Joint Application Design (JAD)

Structured process involving users,

analysts, and managers.

Several-day intensive workgroup sessions.

Purpose: to specify or review system

requirements.

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Rapid Application Development

(RAD)Methodology to radically decrease

design and implementation time.

Involves: extensive user involvement,

prototyping, JAD sessions, integrated

CASE tools, and code generators.

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Rapid Application Development

(RAD) (Cont.)

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Agile Methodologies

Motivated by recognition of software

development as fluid, unpredictable, and

dynamic. Three key principles

Adaptive rather than predictive.

Emphasize people rather than roles.

Self-adaptive processes.

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eXtreme Programming

Short, incremental development cycles.

Automated tests.

Two-person programming teams.

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eXtreme Programming (Cont.)

Coding and testing operate together.

Advantages:

Communication between developers.

High level of productivity.

High-quality code.

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Object-Oriented Analysis and

Design (OOAD) Based on objects rather than data or

processes.

Combines data and processes (methods)into single entities called objects

Object: a structure encapsulatingattributes and behaviors of a real-worldentity.

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Object-Oriented Analysis and

Design (OOAD) (Cont.)Object class: a logical grouping of

objects sharing the same attributes

and behaviors.

Inheritance: hierarchical

arrangement of classes enablesubclasses to inherit properties ofsuperclasses.

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Rational Unified Process (RUP)

An object-oriented systems development

methodology.

RUP establishes four phase ofdevelopment: inception, elaboration,

construction, and transition.

Each phase is organized into a number ofseparate iterations.

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Phases of OOSAD-based

Development

Figure 1-14 Phases of OOSAD-based development

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Summary

In this chapter you learned how to:

Define information systems analysis and

design.

Describe the different types of information

systems.

Describe the information Systems

Development Life Cycle (SDLC).

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Summary (Cont.)

Explain Rapid Application Development

(RAD), prototyping, Joint Application

Development (JAD), and Computer Aided

Software Engineering (CASE).Describe agile methodologies and eXtreme

programming.

Explain Object Oriented Analysis and

Design and the Rational Unified Process

(RUP).

Documents

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