Dennis M. Buede - The Engineering Design of Systems: Models and Methods

Andrew P. Sage, Founding Editor

A complete list of the titles in this series appears at the end of this volume.

Third Edition

Dennis M. Buede

Innovative Decisions, Inc.
Reston, Virginia

William D. Miller

Innovative Decisions, Inc.
Berkeley Heights, New Jersey

Copyright 2016 by John Wiley & Sons, Inc. All rights reserved

Published by John Wiley & Sons, Inc., Hoboken, New Jersey
Published simultaneously in Canada

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Library of Congress Cataloging-in-Publication Data applied for.

ISBN: 9781119027904

Dennis: In memory of my Mother and Father

Bill: To John Lewis, Mal Buchner, Jake Schaefer,
and Les Kleinberg who inspired and
nurtured this nascent systems engineer

This book is meant to be a basic text for courses in the engineering design of systems at both the upper division undergraduate and beginning graduate levels. The book is the product of many years of consulting on numerous portions of the system development process, research into the use of systems engineering in industry, and 6 years developing a course on the engineering design of systems. During the development of this book, I found that many engineers did not understand systems engineering. Even those who do may not have a good perspective on a complete and unified process for engineering a system. The desire to suppress the number of decisions being made during design is quite strong in most engineers. While engineers have learned modeling throughout their academic life, and most have developed models during the practice of engineering, very few engineers working on systems are knowledgeable of the modeling techniques required in systems engineering. In addition, most engineers are not aware of methods for using models during the systems engineering process. As a result, I adopted the following themes in formulating this book:

1. Defining the design problem in systems engineering is one of several keys to success and can be approached systematically using engineering techniques.
2. The design problem in systems engineering is defined in terms of requirements. These requirements evolve from a high-level set of mission and stakeholders' requirements to detailed sets of derived requirements.
3. The design process will fail if the requirements are defined too narrowly, leaving little if any room for design decisions and raising the possibility that no feasible solution exists. The design problem should be well defined and decision rich.
4. For the design problem to be well defined, the evolving sets of requirements must be complete (none missing), consistent (no contradictions), correct (valid for an acceptable solution), and attainable (an acceptable solution exists). While it is not possible at this time to state requirements mathematically and prove these properties, it is possible to develop mathematical and heuristic representations of the design problem to assist in evaluating the presence of these properties.
5. These characteristics of the requirements will not be achieved if scenarios defining how the system will be used are not elaborated in detail, the interactions among the system and other systems are not defined, and the stakeholders' objectives are not understood. Each of these requires a different kind of modeling to be successful.
6. The design problem is not likely to be well defined if the requirements do not address every relevant phase of the system's life cycle.
7. The design problem is not likely to be well defined if the requirements do not contain stakeholder preferences for comparing feasible designs against each other.
8. The keys to understanding many of the modeling techniques for developing requirements, defining architectures, and deriving requirements are found in discrete mathematics: set theory, relations and functions, and graph theory.
9. Integration requires a well-defined design, including a design of the qualification process for verification, validation, and acceptance. A systematic process of design provides all of the necessary inputs for defining the qualification process.
10. Early validation of the evolution of the definition of the design problem needs to be pursued vigorously to ensure that the definition of the design problem does not change as the problem is defined in greater detail.
11. Qualification of the system is the key issue in integration. Qualification includes verification and validation of both the requirements and the system design, followed by the stakeholders' acceptance. There are many methods for qualifying the system; these methods must be chosen judiciously.
12. Successful qualification also requires that decisions about what should be tested be made in a systematic way that balances the two conflicting objectives of not wasting resources and obtaining stakeholder acceptance.

The major changes made in the third edition is the addition of three new chapters: has been rewritten to address the integration of the new chapters and updates have been made throughout the original chapters.

The book is divided into three major parts: (1) Introduction, Overview and Basic Knowledge, (2) Design and Integration Topics, and (3) Supplemental Topics. The first part provides an introduction to the issues associated with the engineering of a system. Next, an overview of the engineering process is provided so that readers will have a context for the more detailed material. Finally, basic knowledge needed for the core material is presented. Homework problems are provided at the end of each chapter.