Model-Based System Architecture (eBook)

TIM WEILKIENS is Executive Board Member of Oose, a German engineering consultancy, and a co-author of the SysML specification. JESKO G. LAMM is a Senior Systems Engineer in the European hearing healthcare industry. STEPHAN ROTH is a coach, consultant, and trainer for systems and software engineering at oose. He is a certified systems engineer (GfSE)¯®- Level C. MARKUS WALKER is Elevator System Architect in the CTO Division at Schindler Elevator. He is an INCOSE Certified Systems Engineering Professional (CSEP).

Cover 1
Title Page 5
Copyright 6
Contents 7
Foreword 17
Preface 19
About the Companion Website 23
Chapter 1 Introduction 25
Chapter 2 An Example: The Scalable Observation and Rescue System 29
Chapter 3 Better Products?–?The Value of Systems Architecting 33
3.1 The Share of Systems Architecting in Making Better Products 33
3.2 Benefits that can be Achieved 34
3.2.1 Benefit for the Customer 34
3.2.2 Benefit for the Organization 36
3.3 Benefits that can be Communicated Inside the Organization 38
3.4 Beneficial Elements of Systems Architecting 39
3.5 Benefits of Model?Based Systems Architecting 40
Chapter 4 Systems, Systems of Systems, and Cyber?Physical Systems* 41
4.1 Definition of “System” 41
4.1.1 System Elements 43
4.1.2 System Context 44
4.1.3 System Characteristics 45
4.1.4 Purpose 46
4.1.5 System Evolution 47
4.2 Definition of “System of Systems” 47
4.3 Definition of “Cyber?Physical System” 50
4.4 Composition of a “Cyber?Physical System of Systems” 51
Chapter 5 Definition of System Architecture 55
5.1 What Is Architecture??–?Discussion of Some Existing Definitions 55
5.2 Relations Between Concepts of “System,” “Architecture,” and “Architecture Description” 57
5.3 Definition of “Architecture” 59
5.3.1 Interactions 60
5.3.2 Principles 61
5.3.3 Architecture Decisions 61
5.4 Functional and Physical Architecture 61
5.5 Taxonomy of Physical Architectures 63
5.5.1 Logical Architecture 64
5.5.2 Product Architecture 65
5.5.3 Base Architecture 65
5.6 Architecture Landscape for Systems 65
5.6.1 System Architecture 66
5.6.2 System Design 67
5.6.3 Discipline?Specific Architecture and Design 68
Chapter 6 Model?Based Systems Architecting 69
Chapter 7 Model Governance 75
7.1 Overview 75
7.2 Model Governance in Practice 76
Chapter 8 Architecture Description 81
8.1 Architecture Descriptions for Stakeholders 82
8.2 Definition of “Architecture Description” 84
8.2.1 Architecture Viewpoints 86
8.2.2 Architecture Views 89
8.2.3 Architecture Decisions 91
8.2.4 Architecture Rationales 93
8.3 How to Get Architecture Descriptions? 93
8.3.1 Model?Based Vision 93
8.3.2 Forms and Templates 95
Chapter 9 Architecture Patterns and Principles 99
9.1 The SYSMOD Zigzag Pattern 100
9.2 The Base Architecture 106
9.3 Cohesion and Coupling 109
9.4 Separation of Definition, Usage, and Run?Time 111
9.5 Separate Stable from Unstable Parts 113
9.6 The Ideal System 113
9.7 View and Model 114
9.8 Diagram Layout 116
9.9 System Model Structure 117
9.10 System Architecture Principles 119
9.11 Heuristics 119
9.11.1 Heuristics as a Tool for the System Architect 119
9.11.2 Simplify, Simplify, Simplify: Strength and Pitfall 121
Chapter 10 Model?Based Requirements Engineering and Use Case Analysis 123
10.1 Requirement and Use Case Definitions 123
10.2 Model?Based Requirements and Use Case Analysis from the MBSA Viewpoint 126
10.2.1 Identify and Define Requirements 127
10.2.2 Specify the System Context 128
10.2.3 Identify Use Cases 129
10.2.4 Describe Use Case Flows 133
10.2.5 Model the Domain Knowledge 134
10.3 The SAMS Method 136
10.3.1 SAMS Method Definitions 137
10.3.2 SAMS Method 138
10.4 Use Cases 2.0 141
Chapter 11 Perspectives, Viewpoints and Views in System Architecture* 143
11.1 Introduction 143
11.2 The Functional Perspective 145
11.2.1 SysML Modeling of Functional Blocks 147
11.2.2 Architecture Views for the System Architect 148
11.2.3 Different Architecture Views for the Stakeholders of Different Functions 148
11.3 The Physical Perspective 149
11.3.1 Logical Architecture Example 150
11.3.2 Product Architecture Example 151
11.4 The Behavioral Perspective 154
11.5 The Layered Perspective 154
11.5.1 The Layered Approach 154
11.5.2 The Layered Perspective in Systems Architecting 156
11.5.3 Relation to the Domain Knowledge Model 158
11.5.4 Architecting the Layers 160
11.5.5 SysML Modeling of Layers 160
11.6 System Deployment Perspective 166
11.7 Other Perspectives 168
11.8 Relation to the System Context 170
11.8.1 Validity of the System Boundary 170
11.8.2 Using the System Context as a Part of the Stakeholder?Specific Views 170
11.8.3 Special System Context View for Verification 171
11.9 Mapping Different System Elements Across Different Levels 172
11.9.1 Functional?to?Physical Perspective Mapping 173
11.9.2 Mapping More Perspectives 177
11.9.3 Mapping Different Levels 177
11.10 Traceability 179
11.11 Perspectives and Architecture Views in Model?based Systems Architecting 179
11.11.1 Creating Different Architecture Views in a Model?Based Approach 179
11.11.2 Using SysML for Working with Different Perspectives and Architecture Views 181
11.11.3 The Importance of Architecture Viewpoints in Model?Based Systems Architecting 183
Chapter 12 Typical Architecture Stakeholders 185
12.1 Overview 185
12.2 Requirements Engineering 186
12.3 Verification 187
12.4 Configuration Management 190
12.5 Engineering and Information Technology Disciplines 191
12.6 Project and Product Management 195
12.7 Risk Managers 198
12.8 Development Roadmap Planners 198
12.9 Production and Distribution 201
12.10 Suppliers 202
12.11 Marketing and Brand Management 202
12.12 Management 204
Chapter 13 Roles 209
13.1 Roles 209
13.2 The System Architect Role 210
13.2.1 Objective 210
13.2.2 Responsibilities 210
13.2.3 Tasks 211
13.2.4 Competences 212
13.2.5 Required Skills of a System Architect 212
13.2.6 Required Skills for Model?Based Systems Architecting 214
13.3 System Architecture Teams 214
13.4 System Architecture Stakeholders 216
13.5 Recruiting System Architecture People 216
13.6 Talent Development for System Architects 218
Chapter 14 Processes 223
14.1 Systems Architecting Processes 223
14.1.1 Overview 223
14.1.2 Example of Generic Process Steps 225
14.1.3 Example of Concrete Process Steps 226
14.1.4 Validation, Review, and Approval in a Model?Based Environment 227
14.2 Design Definition Process 231
14.3 Change and Configuration Management Processes 231
14.4 Other Processes Involving the System Architect 231
Chapter 15 Tools for the Architect 233
Chapter 16 Agile Approaches 237
16.1 The History of Iterative–Incremental Approaches 238
16.1.1 Project Mercury (NASA, 1958) 238
16.1.2 The New New Product Development Game (1986) 239
16.1.3 Boehm's Spiral Model (1988) 240
16.1.4 Lean (1945 Onwards) 241
16.1.5 Dynamic Systems Development Method (DSDM, 1994) 243
16.1.6 Scrum (1995) 244
16.2 The Manifesto for Agile Software Development (2001) 245
16.3 Agile Principles in Systems Engineering 247
16.3.1 Facilitate Face?to?Face Communication 247
16.3.2 Create a State of Confidence 248
16.3.3 Build Transdisciplinary and Self?Organized Teams 249
16.3.4 Create a Learning Organization 249
16.3.5 Design, but No Big Design (Up?Front) 250
16.3.6 Reduce Dependencies 251
16.3.7 Foster a Positive Error Culture 252
16.4 Scaling Agile 252
16.5 System Architects in an Agile Environment 254
Chapter 17 The FAS Method 257
17.1 Motivation 258
17.2 Functional Architectures for Systems 260
17.3 How the FAS Method Works 263
17.4 FAS Heuristics 266
17.5 FAS with SysML 268
17.5.1 Identifying Functional Groups 268
17.5.2 Modeling the Function Structure 270
17.5.3 Modeling the Functional Architecture 273
17.6 SysML Modeling Tool Support 274
17.6.1 Create Initial Functional Groups 275
17.6.2 Changing and Adding Functional Groups 278
17.6.3 Creating Functional Blocks and their Interfaces 278
17.7 Mapping of a Functional Architecture to a Physical Architecture 278
17.8 Experiences with the FAS Method 280
17.9 FAS Workshops 282
17.10 Quality Requirements and the Functional Architecture 283
17.11 Functional Architectures and the Zigzag Pattern 286
17.12 CPS?FAS for Cyber?physical Systems 287
Chapter 18 Product Lines and Variants 293
18.1 Definitions Variant Modeling 294
18.2 Variant Modeling with SysML 295
18.3 Other Variant Modeling Techniques 300
Chapter 19 Architecture Frameworks 303
19.1 Enterprise Architectures 304
19.2 Characteristics of System of Systems (SoS) 306
19.2.1 Emergence 307
19.3 An Overview of Architecture Frameworks 309
19.3.1 Zachman Framework™ 309
19.3.2 The TOGAF® Standard 310
19.3.3 Federal Enterprise Architecture Framework (FEAF) 312
19.3.4 Department of Defense Architecture Framework (DoDAF) 313
19.3.5 Ministry of Defense Architecture Framework (MODAF) 314
19.3.6 NATO Architecture Framework (NAF) 315
19.3.7 TRAK 316
19.3.8 European Space Agency Architectural Framework (ESA?AF) 317
19.3.9 OMG Unified Architecture Framework® (UAF®) 319
19.4 System Architecture Framework (SAF) 320
Together with Michael Leute 320
19.4.1 SAF and Enterprise Frameworks 320
19.4.2 SAF Ontology 322
19.5 What to Do When We Come in Touch With Architecture Frameworks 322
Chapter 20 Cross?cutting Concerns 325
20.1 The Game?Winning Nonfunctional Aspects 325
20.2 Human System Interaction and Human Factors Engineering 327
20.3 Risk Management 328
20.4 Trade Studies 329
20.5 Budgets 330
Chapter 21 Architecture Assessment 331
Chapter 22 Making It Work in the Organization 337
22.1 Overview 337
22.2 Organizational Structure for Systems Architecting 338
22.3 Recipes from the Authors' Experience 342
22.3.1 Be Humble 343
22.3.2 Appraise the Stakeholders 343
22.3.3 Care About Organizational Interfaces 343
22.3.4 Show that it Was Always There 345
22.3.5 Lead by Good Example 345
22.3.6 Collect Success Stories and Share them When Appropriate 346
22.3.7 Acknowledge that Infections Beat Dictated Rollout 347
22.3.8 Assign the System Architect Role to Yourself 348
22.3.9 Be a Leader 348
Chapter 23 Soft Skills 351
23.1 It's All About Communication 352
23.1.1 Losses in Communication 353
23.1.2 The Anatomy of a Message 354
23.1.3 Factors Influencing Communication 357
23.1.3.1 The Language 357
23.1.3.2 The Media Used 357
23.1.3.3 Spatial Distance 357
23.1.3.4 Various Connotations of Words 359
23.1.4 The Usage of Communication Aids and Tools 359
23.2 Personality Types 362
23.2.1 Psychological Types by C. G. Jung 362
23.2.2 The 4MAT System by Bernice McCarthy 364
23.3 Team Dynamics 365
23.4 Diversity and Psychological Safety 366
23.4.1 Project Aristotle (Google) 366
23.4.2 Elements of Psychological Safety 367
23.5 Intercultural Collaboration Skills 368
Chapter 24 Outlook: The World After Artificial Intelligence 371
Appendix A OMG Systems Modeling Language 373
A.1 Architecture of the Language 374
A.2 Diagram and Model 376
A.3 Structure Diagrams 377
A.3.1 Block Definition Diagram 378
A.3.2 Internal Block Diagram 381
A.3.3 Parametric Diagram 385
A.3.4 Package Diagram 386
A.4 Behavior Diagrams 387
A.4.1 Use Case Diagram 388
A.4.2 Activity Diagram 390
A.4.3 State Machine Diagram 393
A.4.4 Sequence Diagram 395
A.5 Requirements Diagram 396
A.6 Extension of SysML with Profiles 398
A.7 Next?Generation Modeling Language SysML v2 400
Appendix B The V?Model 405
B.1 A Brief History of the V?Model or the Systems Engineering Vee 405
B.2 A Handy Illustration but No Comprehensive Process Description 407
B.3 Critical Considerations 409
B.3.1 The V?Model as Process Description 410
B.3.2 The V?Model Does Not Impose a Waterfall Process 410
B.3.3 The V?Model Accommodates Iterations 411
B.3.4 The V?Model Permits Incremental Development 411
B.3.5 The V?Model and Concurrent Engineering 412
B.3.6 The V?Model Accommodates Change 412
B.3.7 The V?Model Permits Early Verification Planning 412
B.3.8 The V?Model Shows Where to Prevent Dissatisfaction 412
B.4 Reading Instruction for a Modern Systems Engineering Vee 413
B.4.1 The Vertical Dimension 413
B.4.2 The Horizontal Dimension 413
B.4.3 The Left Side 413
B.4.4 The Right Side 414
B.4.5 The Levels 414
B.4.6 Life Cycle Processes 414
B.4.7 The Third Dimension 414
Appendix C Glossary 415
C.1 Heritage of the Term “Glossary” 415
C.2 Terms with Specific Meaning 417
References 423
Index 441
EULA 467