Systems Analysis And Design

This page is intentionally left blank SYSTEM ANALYSIS AND DESIGN Fifth Edition This page is intentionally left blank SYSTEM ANALYSIS AND DESIGN Fifth Edition ALAN DENNIS Indiana University BARBARA HALEY WIXOM University of Virginia ROBERTA M. ROTH University of Northern Iowa John Wiley & Sons, Inc. http://www.wiley.com/college/dennis CREDITS VP & PUBLISHER: EXECUTIVE EDITOR: EDITORIAL ASSISTANT: MARKETING MANAGER: DESIGNER: SENIOR PRODUCTION MANAGER: SENIOR PRODUCTION EDITOR: Don Fowley Beth Lang Golub Elizabeth Mills Christopher Ruel Maureen Eide Janis Soo Joyce Poh This book was set in 10.5/12 Times New Roman by Aptara and printed and bound by RR Donnelley. The cover was printed by RR Donnelley. This book is printed on acid-free paper. Founded in 1807, John Wiley & Sons, Inc. has been a valued source of knowledge and understanding for more than 200 years, helping people around the world meet their needs and fulfill their aspirations. Our company is built on a foundation of principles that include responsibility to the communities we serve and where we live and work. In 2008, we launched a Corporate Citizenship Initiative, a global effort to address the environmental, social, economic, and ethical challenges we face in our business. Among the issues we are addressing are carbon impact, paper specifications and procurement, ethical conduct within our business and among our vendors, and community and charitable support. For more information, please visit our website: www.wiley.com/go/citizenship. Copyright © 2012, 2009 John Wiley & Sons, Inc. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system or transmitted in any form or by any means, electronic, mechanical, photocopying, recording, scanning or otherwise, except as permitted under Sections 107 or 108 of the 1976 United States Copyright Act, without either the prior written permission of the Publisher, or authorization through payment of the appropriate per-copy fee to the Copyright Clearance Center, Inc. 222 Rosewood Drive, Danvers, MA 01923, website www.copyright.com. Requests to the Publisher for permission should be addressed to the Permissions Department, John Wiley & Sons, Inc., 111 River Street, Hoboken, NJ 07030-5774, (201)748-6011, fax (201)748-6008, website http://www.wiley.com/go/permissions. Evaluation copies are provided to qualified academics and professionals for review purposes only, for use in their courses during the next academic year. These copies are licensed and may not be sold or transferred to a third party. Upon completion of the review period, please return the evaluation copy to Wiley. Return instructions and a free of charge return shipping label are available at www.wiley.com/go/returnlabel. Outside of the United States, please contact your local representative. Library of Congress Cataloging-in-Publication Data Dennis, Alan. Systems analysis and design /Alan Dennis, Barbara Haley Wixom, Roberta M. Roth.–5th ed. p. cm. Includes index. ISBN 978-1-118-05762-9 (acid-free paper) 1. System design. 2. System analysis. 3. Computer architecture. I. Wixom, Barbara Haley, 1969-II. Roth, Roberta M. (Roberta Marie), 1955-III. Title. QA76.9.S88D464 2012 004.2’2–dc23 2011043317 Printed in the United States of America 10 9 8 7 6 5 4 3 2 1 To Kelly To Chris, Haley, and Hannah T