Preface

With more complex systems being designed and utilized, understanding concepts of systems and mastering systems engineering methods are of utmost importance for systems designers. Complexity exists in all levels of systems and their subsystems, even components, which makes the design challenging. Guided by systems science, systems engineering applies scientific theories and models and incorporates the factors of system elements, including humans, machines, and environments, into unified models to analyze the effects of various system elements on system behaviors, which, in turn, seek the optimal course of actions to design these complex systems. Systems engineering is multidisciplinary in nature, integrating concepts, models, and techniques from a number of disciplines, including natural science, social science, and engineering, at both basic research and applied research levels. For the past several decades, systems engineering has grown rapidly in its scope and application and shown significant benefits for the design of large, complex systems.

I have been educating systems engineers for over ten years, teaching systems engineering at both undergraduate and graduate levels. My students are different from most systems engineering majors, as these undergraduate and graduate students have backgrounds in a large variety of areas, including psychology, physiology, and some engineering fields. With my experience teaching students with a variety of backgrounds, I feel that a textbook in systems engineering targeted at nontraditional engineers is in demand. The current systems engineering textbooks are either too technical or at a high conceptual level, giving these students very limited choices. Students need a good book that not only gives them exposure to the concepts of systems and systems engineering, but also enough technical expertise for them to use and apply what they learn on the job. That is the rationale for developing this book.

This book is written primarily for students with diverse backgrounds to learn about systems and systems engineering, and, more specifically, to be able to use and apply the models and methods in the systems engineering field. The materials included in the book have been taught for many years in the Human Factors and Systems Department at Embry-Riddle Aeronautical University; it has integrated feedback from students and colleagues and is written at a level appropriate for those groups of students to learn systems engineering, especially those nonengineering students who have no prior exposure to this subject. Engineering students, on the other hand, may also find this book useful and handy, as it provides a comprehensive overview of the subjects as well as the relevant analysis models and techniques. This book should serve well as a reference book for professional systems engineers.

This book has ten chapters, organized in three parts, including systems and systems engineering concepts (Chapters 1 and 2), systems methods, models, and analytical techniques (Chapters 3 through 9), and systems management and control methods (Chapter 10). The approach leans toward process-oriented and model-based systems engineering, with necessary topics covered in different chapters. Chapter 2 describes the system life cycle and systems engineering design process. Systems design starts with requirements; beginning with a good set of requirements is critical for the success of the design, and developing and analyzing requirements are not usually covered by a systems engineering book; that is why Chapter 3 is dedicated to this subject. It is believed that students will have a solid understanding of system requirements after having read this detailed information; a software package (CORE) is also used to introduce the requirement management process. Chapter 4 describes the design process in greater detail, especially the functional models. Chapters 5 through 9 explain the necessary technical measures and models that most systems designs will involve, including reliability, maintainability, supportability, usability (human factors), decision-making models under risks and uncertainty, optimization models, process models (queuing models and simulation with Arena software), and cost analysis using engineering economy models. The last chapter (Chapter 10) gives a comprehensive overview of systems management based on systems engineering management plans (SEMP) and systems control based on critical path method (CPM) and program evaluation review technique (PERT) models. In terms of the mathematics involved, it is believed that no specific prerequisite requirements are needed, except for fundamental algebra and basic probability and statistics theory; Appendix I is provided at the end of the book for readers to review these materials. This book can be used as a textbook at either undergraduate upper-level or graduate starting-level courses; exercise problems are provided at the end of each chapter for students to gain hands-on experience with the concepts.

I thank each individual who has encouraged me and assisted me in the process of writing this book. Specifically, I would like to thank Meaghan Hart, Julian Archer, and Hemali Virani for their assistance in preparing this book. Special thanks go to the senior editor Cindy Carelli, project coordinator Laurie Oknowsky, project editor Richard Tressider, and Michele Smith of CRC Press for their assistance, advice, and support throughout the process. I would also like to thank Katie Thacker and Bethany Maddox of Vitech Corporation and Jon D. Santavy of Rockwell Automation for their cooperation with the project. And finally, I want to express my appreciation to my family; their love and support are the inspiration for my career.

Dahai Liu