Stephen Withall - Software Requirement Patterns

Copyright 2007 by Stephen Withall

All rights reserved. No part of the contents of this book may be reproduced or transmitted in any form or by any means without the written permission of the publisher.

Library of Congress Control Number: 2007926327

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Developmental Editor: Devon Musgrave Project Editor: Maria Gargiulo Illustrations: Stephen Withall Editorial Production: ICC Macmillan Inc.

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About the Author

Stephen Withall has been working as a software professional since 1979, in a range of roles from programmer to chief technical officer. Along the way, he has accumulated many years experiencing both the satisfactions and the frustrations of business analysis, systems analysis, and specifying requirements. He has worked in diverse environments in companies big and small, in 17 countries across four continents. The first half of his career found him roaming the world of banking and finance, and the second half (so far) in diverse kinds of e-commerce. He actively maintains his hands-on software development skills.

Stephen holds a BSc in Mathematical Sciences from Bristol University, U.K. He lives in Sydney, Australia, and he enjoys going to places where few others are. You can reach him at http://www.withallyourequire.com.

Requirements development is hard! Requirements analysts often are not adequately trained or experienced, so they do the best they can without necessarily knowing how to write high-quality requirements. Analysts struggle with questions such as "Where do I start?," "How do I know when I'm done?," "How detailed should my requirements be?," "Have I missed any requirements?," and "Have I overlooked any critical information in the requirements I've written?" Unfortunately, there's no formulaic approach to the communication-intensive challenge of understanding and specifying requirements.

Stephen Withall's Software Requirement Patterns can help any analyst write better requirements. These patterns provide a way to embody comprehensive and structured knowledge about different types of requirements. Requirements development is a journey of exploration, not just a simple collection or transcription process. The patterns Steve presents can help analysts ask the right questions to properly understand and specify requirements of many types in an appropriate level of detail. From the perspective of "know your audience," the patterns include guidance to assist the developers and testers who must take the requirements to the next development stages. People learn from examples, and they work more efficiently with the help of templates rather than blank pages. To this end, Steve's requirement patterns provide both templates and examples.

These requirements patterns are applicable to a wide variety of projects and products. You can apply the concepts in the book to develop new requirement patterns specific to your own industry, application domain, or product line. Too many projects begin specifying requirements from scratch, but the requirement patterns let organizations effectively reuse requirements knowledge captured on previous projects.

This book communicates a wealth of wisdom and insight for writing stellar requirements. Through the patterns, Steve points out the value of using a consistent style when writing requirements, which can enhance every analyst's capabilities. Even if you don't apply the patterns rigorously, the book contains hundreds of practical tips for specifying better requirements. Use the book as a reference: read the relevant patterns, try them, and absorb the ideas and advice Steve presents. Internalizing those patterns that fit your situation will make them a routine aspect of how you explore, analyze, document, and use software requirements.

Requirement patterns just might represent the next generation of software requirements thinking. Stephen Withall's Software Requirement Patterns will likely remain the definitive treatise on requirement patterns for years to come.

Karl Wiegers
April 2007