Copyright 2002 Prentice-Hall, Inc.

Modern Systems Analysisand Design

Third Edition

Jeffrey A. Hoffer Joey F. George

Joseph S. Valacich

Chapter 19Rapid Application Development

19.1

Learning ObjectivesExplain the Rapid Application Development

(RAD) approach and how it differs from traditional approaches to information systems development

Describe the systems development components essential to RAD

Discuss the conceptual pillars that support the RAD approach

Explain the advantages and disadvantages of RAD as an exclusive systems development methodology

19.2

Rapid Applications Development (RAD)

Systems development methodology created to radically decrease the time needed to design and implement information systems radically.Five key factors

1. Extensive user involvement2. Joint Application Design sessions3. Prototyping4. Integrated CASE tools5. Code generators

19.3

The Process of Developing an Application Rapidly

RAD is a general strategy rather than a single methodologyGoals

To analyze a business process rapidly To design a viable system solution through

intense cooperation between users and developers

To get the finished application into the hands of the users quickly

Traditional SDLC steps are followed, but phases are combinedIteration is limited to design and development phases

19.4

Components of RADUser involvement is key to success

Prototyping is conducted in sessions similar to Joint Application Design (JAD)

Prototyping screens become screens within the production system

CASE tools are used to design the prototypes

19.5

Approaches to RADMartin’s pillars of RAD Four pillars

Tools People Methodology Management

Conversion to RAD within organization should be done with a small group of well-trained and dedicated professionals, called a RAD cell

Over time, cell can grow until RAD is the predominant approach of the information systems unit

19.6

Approaches to RAD

McConnell’s pillars of RAD Four pillars

Avoid classic mistakes Apply development fundamentals Manage risks to avoid catastrophic setbacks Apply schedule-oriented practices

Table 19-1 lists some of McConnell’s 36 classic development mistakes

19.7

Approaches to RAD

McConnell’s pillars of RAD (continued) Development mistakes

Weak personnel Employees that are not as well trained in skills necessary

for success of the project Silver-bullet syndrome

Occurs when developers believe that a new and untried technology is all that is needed to cure the ills of any development project

Feature creep More and more features are added to a system over

course of development Requirements gold-plating

Project may have more requirements than needed19.8

Approaches to RAD

Software tools Case tools can be used for

Prototyping Code generation Example: COOL:Gen

Visual Development Environments Visual Basic Delphi

19.9

Approaches to RADMartin’s RAD Life Cycle Systems requirement determination is done in

context of a discussion of business problems and business areas

User Design End users and IS professionals participate in JAD

workshops CASE tools are used to support prototyping

Construction Designer creates code using code generator End user validates screens and other aspects of design

Cutover New system is delivered to end users

19.10

RAD Success StoriesInprise/Borland’s Delphi U.S. Navy Fleet Modernization

Requirements Move from three character-based systems to a unified,

GUI-based system based on a single database Reasons for choosing Delphi

Support for rapid prototyping Promise of re-use of components

Outcome System developed in 6 months Estimated development savings of 50 percent New system resulted in immediate 20 percent savings due

to reduced maintenance costs

19.11

RAD Success Stories

Inprise/Borland’s Delphi (continued) First National Bank of Chicago

Electronic Federal Tax Payment System Delphi enabled rapid prototyping and

development 10 months of development time 125 programmers 250 million rows of data and 55 gigabytes of

data on-line

19.12

RAD Success StoriesVisualAge for Java Comdata

Modular Over the Road System (MOTRS) IBM Global Services chosen as vendor Servlets

Programming modules that expand the functions of the Web server

Applets Embedded code run from client browser

Nine months to completion Three months of research Three months of coding Three months of testing

19.13

Advantages DisadvantagesDramatic time savings the systems development effort

More speed and lower cost may lead to lower overall system quality

Can save time, money and human effort

Danger of misalignment of system developed via RAD with the business due to missing information

Tighter fit between user requirements and system specifications

May have inconsistent internal designs within and across systems

Works especially well where speed of development is important

Possible violation of programming standards related to inconsistent naming conventions and inconsistent documentation

Ability to rapidly change system design as demanded by users

Difficulty with module reuse for future systems

System optimized for users involved in RAD process

Lack of scalability designed into system

Concentrates on essential system elements from user viewpoint

Lack of attention to later systems administration built into system

Strong user stake and ownership of system

High cost of commitment on the part of key user personnel

19.14

SummaryRapid Application Development Approach (RAD)

Components of RAD

Conceptual pillars that support RAD

RAD success stories

Advantages and Disadvantages of RAD

19.15