Langer - Analysis and Design of Information Systems 3e (Springer, 2008).pdf - Methodology - Yohoho25

Arthur M. Langer

Analysis and Design

of Information

Systems

Third Edition

Arthur M. Langer, EdD

Fu Foundation School of Engineering & Applied Science

School of Continuing Education

Graduate School of Education

Columbia University

New York, NY 10027

USA

British Library Cataloguing in Publication Data

A catalogue record for this book is available from the British Library

Library of Congress Control Number: 2007928317

ISBN 978-1-84628-654-4 e-ISBN 978-1-84628-655-1

Printed on acid-free paper

Apart from any fair dealing for the purposes of research or private study, or criticism or review,

as permitted under the Copyright, Designs and Patents Act 1988, this publication may only be

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The use of registered names, trademarks, etc., in this publication does not imply, even in the

absence of a specific statement, that such names are exempt from the relevant laws and regulations

and therefore free for general use.

The publisher makes no representation, express or implied, with regard to the accuracy of the

information contained in this book and cannot accept any legal responsibility or liability for any

errors or omissions that may be made.

987654321

Springer Science+Business Media

springer.com

Preface

Throughout the last 40 years the impact and importance of information

technology (IT) continues to transform the world. Indeed, we are very much

at the beginning stages of what I believe will be known as the technology

revolution—a revolution that will change every aspect of business and life in

general. While technology, both hardware and software, continues to evolve,

the one remaining constant is the challenge of understanding what the users of

applications really need, what they think they want, and what they will want as

their uses of systems mature.

Still, the process of mastering the analysis and design phase of the Software

Development Life Cycle (SDLC) continues to perplex the most sophisticated IT

organizations and software development companies. And to make matters even

more complex, the IT industry has transitioned to a heavily outsourced model of

software development, making the requirements of what is necessary even more

important because of the risks of having applications developed abroad that do

not meet user expectations.

Perhaps the most significant development in applications has been the

Internet, with all the corresponding pieces: branding, Web development, and

interactive user interfaces have established many more substantial challenges

to how applications evolve. The most critical change, however, is the partici-

pation of a more sophisticated and unknown user: the consumer. The consumer

is a most unusual individual: he/she does not participate as part of an internal

organization, or external client, rather a transactional force that comes in and

out of the application with an enormous amount of uncertainty and constant

change in behaviors and needs. Furthermore, this “consumer” represents a broad

population, of culture, age, gender, and ethnicity differences.

With the significant challenges described above, it is imperative that we

expand analysis and design to provide developers from inside and outside the

business to clearly understand what is needed. Furthermore, applications need

to change more often, so that object-based design is no longer an alternative,

rather a necessity to allow organizations to continually evolve and mature their

abilities to serve their clientele. This book then focuses on providing direction

on the many alternatives to dealing with all types of systems, from large legacy

applications to on-line transactional systems that interface with a myriad of

internal and external systems.

Many of these failures of systems developed have occurred because they have

not been built on strong foundations. In particular, there is a lack of understanding

of the engineering processes through which applications must be built. This book

Preface

seeks to remedy this problem by focusing on the applied aspects of analysis to

create systems that meet the needs of their users, consumers, and businesses.

The analyst/designer encounters many obstacles on the road to designing appli-

cations. Many of these obstacles have nothing to do with technical challenges at

all—they are problems that come from outside the realm of IT: politics, budget

and time constraints, and marketing pressures. All of these can challenge the

structured approach to analysis and design. This book addresses these obstacles

and recommends ways to overcome them. I have always warned my students by

telling them: “Follow the Yellow Brick Road.” That is, start out on the right path

and you will end up in the place you want to be—in spite of all the obstacles

you may encounter on the way. I hope this book shows many IT professionals

that the analyst/designer is the most important component of the SDLC.

This new edition aims to enhance the set of techniques and tools that the

analyst/designer requires for success. It also addresses some of the “softer” but

critical other skills such as creativity and the ability to understand the market

needs of the business. Furthermore, the successful analyst/designer must be

able to understand consumer needs; ensure integration with legacy systems;

provide user interface requirements; establish standards, security, and network

architecture; and finally to provide the necessary project management to ensure

implementation.

New to the Third Edition

This third edition provides more examples and case studies; however, it contains

two major upgrades from its predecessor: first, responding to feedback, I have

framed the modeling tools within an SDLC framework so that readers can have

a step-by-step understanding of when and how to use each of the modeling

tools of analysis. To accomplish this, I provide a popular SDLC approach called

“the Barker Method” which was developed by Richard Barker from Oracle

Corporation. Second, the scope of analysis and design has been expanded to

include more specific information on Logic Data Modeling, specifically refer-

ential integrity, naming conventions, logical-to-physical design steps, XML, data

values, and denormalization. I have also added new chapters on Web interface

tools, security and change control and data warehouse system design.

The Aim of This Book

The risks involved in performing analysis are significant: Those projects that

involve reengineering activities have a failure rate over 70 percent. With the

expansion of the Internet as a vehicle for electronic commerce, the stakes are

even higher than before, and identifying the sources of failure can be invaluable.

In general, failures can be attributed to two kinds of risks: those associated

with the process of change and those relating to the technology itself. I am

Preface vii

confident that the success rate can be dramatically improved if we focus less on

the methodology and more on the ability of the analyst to perform the work. This

book is therefore meant as a “practitioners guide” to doing analysis through

every facet of developing software solutions.

The book defines the word “analyst” to include any individual involved

in establishing the requirements and design of a system. For this reason, the

book includes subjects like joint application development (JAD) and prototyping,

which may not always be performed by analysts but which nevertheless fall

within the confines of the definition.

My enthusiasm for writing this book was supported by many of my students

who found that existing books on analysis are:

very theoretical. Although they explain the methodologies, they do not

provide enough examples of their actual application.

too procedural. They do not deal with the “human” aspects of devel-

oping requirements and thus do not provide a complete understanding

of how to be successful. After all, the whole point of analysis is to

service human enterprises, not just to create systems for their own sake.

The human side of analysis is as important as the technical side.

lacking simple but effective case examples. The examples do not demon-

strate the concepts effectively or are too complex for practice study.

too one-sided in their views. It is important to establish all available

methodologies, even those that conflict with each other. Putting opinions

into perspective and leaving many of the ultimate decisions to the

practitioner is a significant part of the analysts education.

The Intended Audience for This Book

This book assumes a reasonable understanding of computer concepts and termi-

nology. The material is presented to be used in a first-level analysis course

or university program. In addition, it can be used by practicing information

systems professionals or executives who are managing information technology

and need an in-depth understanding of the principles of the analysis and design

process, particularly as it relates to Web-based development. Furthermore, many

programmers who are also performing analysis may find this book a way of

developing a useful approach to structured and object methodologies.

Acknowledgments

I want to thank my colleague Melanie Caffrey for her contributions to the Third

Edition, namely, her expertise in both the System Development Life Cycle and

the Barker Model was extremely valuable. Ms. Caffrey also contributed her

exercises and case study used in our courses at Columbia University.

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