Model-based Systems Architecting

Model-based Systems Architecting is a key tool for designing complex industrial systems. It is dedicated to the working systems architects, engineers and modelers, in order to help them master the complex integrated systems that they are dealing with in their day-to-day professional lives.

It presents the CESAMES Systems Architecting Method (CESAM), a systems architecting and modeling framework which has been developed since 2003 in close interaction with many leading industrial companies, providing rigorous and unambiguous semantics for all classical systems architecture concepts. This approach is practically robust and easy-to-use: during the last decade, it was deployed in more than 2,000 real system development projects within the industry, and distributed to around 10,000 engineers around the globe. DANIEL KROB is one of the leading world experts in systems architecting and engineering. He was Institute Professor at Ecole Polytechnique, Palaiseau, France, and founder and Director of its Industrial Chair dedicated to complex systems engineering for more than 15 years. He is currently President of the Center of Excellence on Systems Architecture, Management, Economy & Strategy (CESAMES) and has been an INCOSE Fellow since 2014.

Preface ix

Acknowledgments xv

Introduction xvii

CHAPTER 1 INTRODUCTION TO CESAM 1

1.1 CESAM: a mathematically sound system modeling framework 1

1.2 CESAM: a framework focused on complex integrated systems 8

1.3 CESAM: a collaboration-oriented architecting framework 12

1.4 CESAM: a business-oriented framework 16

CHAPTER 2 WHY ARCHITECTING SYSTEMS? 19

2.1 Product and project systems 19

2.2 The complexity threshold 22

2.3 Addressing systems architecting becomes key 25

2.4 The value of systems architecting 31

2.5 The key role of systems architects 34

2.6 How to analyze a systems architect profile? 36

CHAPTER 3 CESAM FRAMEWORK 39

3.1 Elements of systemics 39

3.1.1 Interface 39

3.1.2 Environment of a system 41

3.2 The three architectural visions 42

3.2.1 Architectural visions definition 42

3.2.2 Architectural visions overview 46

3.2.3 Relationships between the three architectural visions 52

3.2.4 Organization of a system model 55

3.3 CESAM systems architecture pyramid 57

3.3.1 The three key questions to ask 57

3.3.2 The last question that shall not be forgotten 59

3.4 More systems architecture dimensions 60

3.4.1 Descriptions versus expected properties 60

3.4.2 Descriptions 62

3.4.3 Expected properties 73

3.5 CESAM systems architecture matrix 78

CHAPTER 4 IDENTIFYING STAKEHOLDERS: ENVIRONMENT ARCHITECTURE 83

4.1 Why identify stakeholders? 83

4.2 The key deliverables of environment architecture 85

4.2.1 Stakeholder hierarchy diagram 85

4.2.2 Environment diagram 87

CHAPTER 5 UNDERSTANDING INTERACTIONS WITH STAKEHOLDERS: OPERATIONAL ARCHITECTURE 91

5.1 Why understand interactions with stakeholders? 91

5.2 The key deliverables of operational architecture 94

5.2.1 Need architecture diagram 94

5.2.2 Lifecycle diagram 95

5.2.3 Use case diagrams 97

5.2.4 Operational scenario diagrams 99

5.2.5 Operational flow diagram 101

CHAPTER 6 DEFINING WHAT THE SYSTEM SHALL DO: FUNCTIONAL ARCHITECTURE 103

6.1 Why understand what the system does? 103

6.2 The key deliverables of functional architecture 105

6.2.1 Functional requirement architecture diagram 106

6.2.2 Functional mode diagram 108

6.2.3 Functional breakdown and interaction diagrams 109

6.2.4 Functional scenario diagrams 111

6.2.5 Functional flow diagram 112

CHAPTER 7 DECIDING HOW THE SYSTEM SHALL BE FORMED: CONSTRUCTIONAL ARCHITECTURE 115

7.1 Understanding how the system is formed? 115

7.2 The key deliverables of constructional architecture 117

7.2.1 Constructional requirement architecture diagram 118

7.2.2 Configuration diagram 120

7.2.3 Constructional breakdown and interaction diagram 121

7.2.4 Constructional scenario diagram 123

7.2.5 Constructional flow diagram 124

CHAPTER 8 TAKING INTO ACCOUNT FAILURES: DYSFUNCTIONAL ANALYSIS 127

8.1 Systems do not always behave as they should 127

8.2 The key deliverables of dysfunctional analysis 134

8.2.1 Dysfunctional analysis from an operational perspective 135

8.2.2 Dysfunctional analysis from a functional perspective 136

8.2.3 Dysfunctional analysis from a constructional perspective 138

CHAPTER 9 CHOOSING THE BEST ARCHITECTURE: TRADE-OFF TECHNIQUES 141

9.1 Systems architecting does not usually lead to a unique solution 141

9.2 Trade-off techniques 143

9.2.1 General structure of a trade-off process 143

9.2.2 Managing trade-offs in practice 145

Conclusion 149

APPENDICES 157

Appendix 1 System Temporal Logic 159

Appendix 2 Classical Engineering Issues 163

Appendix 3 Example of System Model Managed with CESAM 177

Appendix 4 Implementing CESAM through a SysML Modeling Tool 199

Appendix 5 Some Good Practices in Systems Modeling 209

References 211

Index 219