Trade-off Analytics

Creating and Exploring the System Tradespace

Gregory S. Parnell

• Publisher: Wiley
• Year: 2016
• ISBN:
  9781119238300
• Edition: 1
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

Presentsinformationto create a trade-off analysis framework for use in government and commercial acquisition environments

This book presents a decision management process based on decision theory and cost analysis best practices aligned with the ISO/IEC 15288, the Systems Engineering Handbook, and the Systems Engineering Body of Knowledge. It provides a sound trade-off analysis framework to generate the tradespace and evaluate value and risk to support system decision-making throughout the life cycle. Trade-off analysis and risk analysis techniques are examined. The authors present an integrated value trade-off and risk analysis framework based on decision theory. These trade-off analysis concepts are illustrated in the different life cycle stages using multiple examples from defense and commercial domains.

• Provides techniques to identify and structure stakeholder objectives and creative, doable alternatives
• Presents the advantages and disadvantages of tradespace creation and exploration techniques for trade-off analysis of concepts, architectures, design, operations, and retirement
• Covers the sources of uncertainty in the system life cycle and examines how to identify, assess, and model uncertainty using probability
• Illustrates how to perform a trade-off analysis using the INCOSE Decision Management Process using both deterministic and probabilistic techniques

Trade-off Analytics: Creating and Exploring the System Tradespace is written for upper undergraduate students and graduate students studying systems design, systems engineering, industrial engineering and engineering management. This book also serves as a resource for practicing systems designers, systems engineers, project managers, and engineering managers.

Gregory S. Parnell, PhD, is a Research Professor in the Department of Industrial Engineering at the University of Arkansas. He is also a senior principal with Innovative Decisions, Inc., a decision and risk analysis firm and has served as Chairman of the Board. Dr. Parnell has published more than 100 papers and book chapters and was lead editor of Decision Making for Systems Engineering and Management, Wiley Series in Systems Engineering (2nd Ed, Wiley 2011)and lead author of the Handbook of Decision Analysis (Wiley 2013). He is a fellow of INFORMS, the INCOSE, MORS, and the Society for Decision Professionals.

Chapter 1
Introduction to Trade-Off Analysis

Gregory S. Parnell

Department of Industrial Engineering, University of Arkansas, Fayetteville, AR, USA

Matthew Cilli

U.S. Army Armament Research Development and Engineering Center (ARDEC), Picatinny, NJ, USA

Azad M. Madni

Department of Astronautical Engineering, Systems Architecting and Engineering and Astronautical Engineering, Viterbi School of Engineering, University of Southern California, Los Angeles, CA, USA

Garry Roedler

Corporate Engineering LM Fellow, Engineering Outreach Program Manager, Lockheed Martin Corporation King of Prussia, PA

The complexity of man-made systems has increased to an unprecedented level. This has led to new opportunities, but also to increased challenges for the organizations that create and utilize systems.

(ISO/IEC/IEEE 15288, 2015)

1.1 Introduction

This book is about trade-off analyses in the life cycle of a system. It is written from the perspective of engineers, systems engineers, and other decision-makers involved in the life cycle of a system. In this book, we present the best practices for performing systems engineering trade-off analyses in a step-by-step, structured manner. Our intent is to make it an easy-to-understand and useful reference for students, practitioners, and researchers.

Systems are developed to create value for stakeholders by providing desired capabilities. Stakeholders include investors, government agencies, customers/acquirers, end users/operators, system developers/integrators, trainers, and system maintainers, among others. Decisions are ubiquitous across the system life cycle. System decision-makers (DMs) are those individuals who make important decisions pertaining to the technical and management compromises that shape the concept definition, system definition, system realization, deployment and use, and product and service life management (including maintenance, enhancement, and disposal).

When there are multiple stakeholders, there are often competing objectives and requirements. To achieve a certain attainment level on one objective, a sacrifice or trade-off may be required in the attainment level of other objectives. Similarly, complex system designs may offer multiple alternatives to achieve the system's objectives, and this, too, requires analysis to achieve the best balance among the trade-offs. The process that leads to a reasoned compromise in these situations is commonly referred to as a “trade-off analysis” or a “trade study.”

This book project began with a request by the International Council on Systems Engineering (INCOSE) (INCOSE Home Page, 2015) Corporate Advisory Board (CAB) to the INCOSE Decision Analysis Working Group. The CAB identified the lack of effective trade-off analysis methods as a key concern and requested help in documenting best practices. This book project was also motivated by the need to formalize systems engineering trade-off analysis to help make it an integral part of the systems engineering life cycle. It provides essential elaboration of the decision management process in ISO/IEC/IEEE 15288, Systems and Software Engineering – System Life Cycle Processes, the INCOSE Systems Engineering Handbook Version 4, and the Systems Engineering Body of Knowledge (SEBoK, 2015).

Decision-makers (DM), especially program managers and systems engineers, stand to benefit from a collaborative decision management process that engages all stakeholders (SH) who have a say in system design decisions. In particular, systems engineers can exploit trade-off studies to help define the problem/opportunity, characterize the solution space, identify sources of value, identify and evaluate alternatives, identify risks, acquire insights, and provide recommendations to system SHs and other DMs.

This book focuses on engineering trade-off analysis techniques for both systems and systems of systems (Madni and Sievers, 2014a,b; Ordoukhanian and Madni, 2015). We recommend that trade-off studies be consistent with SE standards (ISO/IEC/IEEE 15288:2015), based on a formal lexicon, have a sound mathematical foundation, and provide credible and timely data to DMs and other SHs. We provide such a lexicon and a formal foundation (Chapter 2) based on decision analysis for effective and efficient trade-off studies. Our approach supplements decision analysis, a central part of decision-based design (Hazelrigg, 1998), with Value-Focused Thinking (Keeney, 1992) within a model-based engineering framework (Madni & Sievers, 2015).

1.2 Trade-off Analyses Throughout the Life Cycle

New system development entails a number of interrelated decisions. Table 1.1 provides a partial list of decisions opportunities to improve the system value that are commonly encountered throughout a system's life cycle. Many of these decisions stand to benefit from a holistic perspective that combines the systems engineering discipline with a composite decision model that aggregates the data produced by engineering, performance, and cost models and translates them into terms that are relevant and meaningful to the various stakeholders, especially DMs. This holistic perspective is especially valuable in gate (go/no-go funding) decisions to ensure that affordable alternatives are available for the next life cycle stage.

Table 1.1 Partial List of Decision Opportunities throughout the L...

Table of contents

• Cover
• Title Page
• Copyright
• Table of Contents
• Wiley Series in Systems Engineering and Management
• List of Contributors
• About the Authors
• Foreword
• Preface
• Acknowledgments
• About the Companion Website
• Chapter 1: Introduction to Trade-Off Analysis
• Chapter 2: A Conceptual Framework and Mathematical Foundation for Trade-Off Analysis
• Chapter 3: Quantifying Uncertainty
• Chapter 4: Analyzing Resources
• Chapter 5: Understanding Decision Management
• Chapter 6: Identifying Opportunities
• Chapter 7: Identifying Objectives and Value Measures
• Chapter 8: Developing and Evaluating Alternatives
• Chapter 9: An Integrated Model for Trade-Off Analysis
• Chapter 10: Exploring Concept Trade-Offs
• Chapter 11: Architecture Evaluation Framework
• Chapter 12: Exploring the Design Space
• Chapter 13: Sustainment Related Models and Trade Studies
• Chapter 14: Performing Programmatic Trade-Off Analyses
• Chapter 15: Summary and Future Trends
• Index
• End User License Agreement