Principles of Lean Software Development - …

1 Principles of lean Software Development Eliminate WasteThe three biggest wastes in Software Development are:Extra FeaturesWe need a process that allows us to develop just those 20 percent of the features that give 80 percent of the you have requirements churn, you are specifying too early. If you have test and fix cycles, you are testing too BoundariesOrganizational boundaries can increase costs by 25 percent or more. They create buffers that slow down response time and interfere with Quality In If you routinely find defects in your verification process, your process is Code with Test-Driven DevelopmentWrite executable specifications instead of Building Legacy CodeLegacy code is code that lacks automated unit and acceptance Big Bang Is ObsoleteUse continuous integration and nested KnowledgePlanning is useful. Learning is the Scientific MethodTeach teams to establish hypotheses, conduct many rapid experiments, create concise docu-mentation, and implement the best alternative.

2 Standards Exist to Be Challenged and ImprovedEmbody the current best known practices in standards that are always followed while actively encouraging everyone to challenge and change the Performance Is Driven by FeedbackA predictable organization does not guess about the future and call it a plan; it develops the capacity to rapidly respond to the future as it CommitmentAbolish the idea that it is a good idea to start Development with a complete DependenciesSystem architecture should support the addition of any feature at any OptionsThink of code as an experiment make it Irreversible Decisions at the Last Responsible MomentLearn as much as possible before making irreversible FastLists and queues are buffers between organizations that slow things Delivery, High Quality, and Low Cost Are Fully CompatibleCompanies that compete on the basis of speed have a significant cost advantage, deliver superior quality, and are more attuned to their customers Theory Applies to Development , Not Just ServersFocusing on utilization creates traffic jams that actually reduce utilization.

3 Drive down cycle time with small batches and fewer Work to CapacityEstablish a reliable, repeatable velocity with iterative Development . Aggressively limit the size of lists and queues to your capacity to PeopleEngaged, thinking people provide the most sustainable competitive Thrive on Pride, Commitment, Trust, and ApplauseWhat makes a team? Members are mutually committed to achieve a common Effective LeadershipEffective teams have effective leaders who bring out the best in the PartnersAllegiance to the joint venture must never create a conflict of interest. Optimize the WholeBrilliant products emerge from a unique combination of opportunity and on the Entire Value Stream from concept to cash. from customer request to deployed a Complete ProductDevelop a complete product , not just products are built by complete UPMeasure process capability with cycle team performance with delivered business customer satisfaction with a net promoter for Implementing lean Software Development This book offers a wealth of advice for any organization that wishes to succeed at thesoftware Development game.

4 It will help you to realize the value of adopting a productmindset to Software Development to recognize the inherent wastage and risk in tradi-tional Software Development practices. Mary has hit another one out of the park. Scott Ambler, practice leader, Agile modeling This remarkable book combines practical advice, ready-to-use techniques, and a deepunderstanding of why this is the right way to develop Software . I have seen softwareteams transformed by the ideas in this book. Mike Cohn, author of Agile Estimating and Planning As a lean practitioner myself, I have loved and used their first book for years. Whenthis second book came out, I was delighted that it was even better. If you are interestedin how lean Principles can be useful for Software Development organizations, this is thebook you are looking for. The Poppendiecks offer a beautiful blend of history, theory,and practice. Alan Shalloway, coauthor of Design Patterns Explained I ve enjoyed reading the book very much.

5 I feel it might even be better than the firstlean book by Tom and Mary, while that one was already exceptionally good! Mary espe-cially has a lot of knowledge related to lean techniques in product Development andmanufacturing. It s rare that these techniques are actually translated to Software . This issomething no other book does well (except their first book). Bas Vodde The new book by Mary and Tom Poppendieck provides a well-written and comprehen-sive introduction to lean Principles and selected practices for Software managers andengineers. It illustrates the application of the values and practices with well-suited suc-cess stories. I enjoyed reading it. Roman Pichler In Implementing lean Software Development , the Poppendiecks explore more deeplythe themes they introduced in lean Software Development . They begin with a compel-ling history of lean thinking, then move to key areas such as value, waste, and chapter includes exercises to help you apply key points.

6 If you want a better under-standing of how lean ideas can work with Software , this book is for you. Bill Wake, independent consultantThis page intentionally left blank Implementing lean Software DevelopmentThe Addison-Wesley Signature Series provides readers with practical and authoritative information on the latest trends in modern technology for computer professionals. The series is based on one simple premise: Great books come from great authors. Books in the series are personally chosen by expert advisors, world-class authors in their own right. These experts are proud to put their signatures on the covers, and their signatures ensure that these thought leaders have worked closely with authors to define topic coverage, book scope, critical content, and overall uniqueness. The expert signatures also symbolize a promise to our readers: You are reading a future for a complete list of available Addison-Wesley Signature SeriesKent Beck, Mike Cohn, and Martin Fowler, Consulting EditorsImplementing LeanSoftware DevelopmentFrom Concept to CashMary and Tom PoppendieckUpper Saddle River, NJ Boston Indianapolis San FranciscoNew York Toronto Montreal London Munich Paris MadridCapetown Sydney Tokyo Singapore Mexico CityMany of the designations used by manufacturers and sellers to distinguish their products are claimed as trade-marks.

7 Where those designations appear in this book, and Addison-Wesley was aware of a trademark claim, the designations have been printed with initial capital letters or in all Beans art is used with permission of A Bit Better Corporation. Screen Beans is a registered trademark of A Bit Better authors and publisher have taken care in the preparation of this book, but make no expressed or implied war-ranty of any kind and assume no responsibility for errors or omissions. No liability is assumed for incidental or conse-quential damages in connection with or arising out of the use of the information or programs contained publisher offers excellent discounts on this book when ordered in quantity for bulk purchases or special sales, which may include electronic versions and/or custom covers and content particular to your business, training goals, marketing focus, and branding interests. For more information, please Corporate and Government Sales(800) sales outside of the , please contact:International Book Is Safari EnabledThe Safari Enabled icon on the cover of your favorite technology book means the book is avail-able through Safari Bookshelf.

8 When you buy this book, you get free access to the online edition for 45 Bookshelf is an electronic reference library that lets you easily search thousands of technical books, find code samples, download chapters, and access technical information whenever and wherever you need it. To gain 45-day Safari Enabled access to this book: Go to Complete the brief registration form Enter the coupon code EDGG-GUQI-A1FM-GZI1-K7E3If you have difficulty registering on Safari Bookshelf or accessing the online edition, please e-mail us on the Web: of Congress Cataloging-in-Publication DataPoppendieck, lean Software Development : from concept to cash / Mary Poppendieck, Tom Poppendieck. p. cm. Includes bibliographical references and index. ISBN 0-321-43738-1 (pbk. : alk. paper) 1. Computer Software Development . 2. Production management. I. Poppendieck, Thomas David. II. Title. 2006 dc222006019698 Copyright 2007 Poppendieck LLCAll rights reserved. Printed in the United States of America.

9 This publication is protected by copyright, and permis-sion must be obtained from the publisher prior to any prohibited reproduction, storage in a retrieval system, or transmission in any form or by any means, electronic, mechanical, photocopying, recording, or likewise. For infor-mation regarding permissions, write to:Pearson Education, and Contracts Department75 Arlington Street, Suite 300 Boston, MA 02116 Fax: (617) 848-7047 ISBN 0-321-43738-1 Text printed in the United States on recycled paper at Courier in Stoughton, printing, December 2006To our parents:John and Marge BrustandElmer and Ruth PoppendieckThis page intentionally left blank ixContentsForeword by Jeff Sutherland .. xviiForeword by Kent Beck .. xxPreface .. xxiiiChapter 1: History .. 1 Interchangeable Parts .. 1 Interchangeable People .. 2 The Toyodas .. 3 The Toyota Production System .. 4 Taiichi Ohno .. 5 Just-in-Time Flow .. 5 Autonomation (Jidoka) .. 5 Shigeo Shingo .. 6 Nonstock Production.

10 6 Zero Inspection .. 6 Just-in-Time .. 7 lean .. 11 lean Manufacturing / lean Operations .. 11 lean Supply Chain .. 12 lean product Development .. 13 lean Software Development .. 17 Try This .. 17 Chapter 2: Principles .. 19 Principles and Practices .. 19xCONTENTSS oftware Development .. 20 Software .. 20 Development .. 21 The Seven Principles of lean Software Development .. 23 Principle 1: Eliminate Waste .. 23 Myth: Early Specification Reduces Waste .. 24 Principle 2: Build Quality In .. 25 Myth: The Job of Testing Is to Find Defects .. 28 Principle 3: Create Knowledge .. 29 Myth: Predictions Create Predictability .. 31 Principle 4: Defer Commitment .. 32 Myth: Planning Is Commitment .. 33 Principle 5: Deliver Fast .. 34 Myth: Haste Makes Waste .. 35 Principle 6: Respect People .. 36 Myth: There Is One Best Way .. 37 Principle 7: Optimize the Whole .. 38 Myth: Optimize By Decomposition .. 40 Try This .. 42 Chapter 3: Value.