Architecting Resilient Systems

Scott Jackson is a Principal Engineer at Burnham Systems Consulting, assisting commercial aircraft companies throughout the world in adapting and implementing systems engineering processes across their organizations. He also has taught graduate-level systems engineering courses at the University of Southern California, relying on his experience in systems engineering and engineering leadership roles at Boeing, McDonnell Douglas, and Douglas Aircraft.

Preface or How This Book Came Into Being xiii

Acknowledgment xv

1 Introduction -- On Resilience 1

1.1 The Multidisciplinary Challenge 2

1.2 The Concept of the System 3

1.3 The Paradox of Humans in the System 3

1.4 The Infrastructure as a System 4

1.5 The Architecture of a System 5

1.6 Disruptions 6

1.7 Adaptability 7

1.8 Culture 7

1.9 Measuring Resilience 8

1.10 The Challenges 9

1.11 Identification of Resilience Techniques 9

1.12 Evaluation of Resilience Techniques Through Case Studies 10

1.13 Evaluation of the Techniques 10

1.14 What Is a Technique? 12

1.15 How Statements of Resilience Techniques are Synthesized 13

2 Resilience Literature 15

3 Terms and Definitions 17

3.1 Objective 17

3.2 What Is an Adversity? 17

3.3 Traditional Definitions of Resilience 18

3.4 A Brief Lesson in Abstractions 18

3.5 General features 19

3.6 Glossary of Symbols and Mathematical Characters 19

4 Resilience Abstractions 29

4.1 Objective 29

4.2 What Is System Resilience? 29

4.3 Traditional Definitions of Resilience 30

4.4 Encounter 30

4.5 Abstraction Properties 30

4.6 Concrete Entities 31

5 Methodology 35

5.1 Overview of Methodology 35

5.2 Qualitative Research 35

5.3 Qualitative Interpretation of Solutions Proposed by Domain Experts 35

5.4 Qualitative Judgments of Dependencies Among Resilience Techniques 36

5.5 Qualitative Judgments of Grouping of Resilience Techniques 36

5.6 Interpretation of Historical Events 36

5.7 Objectives of System Resilience 37

6 Techniques 39

6.1 The Robustness Attribute 39

6.2 The Absorption Design Technique 39

6.3 The Physical Redundancy Design Technique 50

6.4 The Functional Redundancy Resilience Technique 57

6.5 The Drift Correction Resilience Technique 64

6.6 The Restructuring Resilience Technique 75

6.7 The Repairability Resilience Technique 83

6.8 The Human Involvement Resilience Technique 89

6.9 The Reduce Hidden Interactions Resilience Technique 98

6.10 The Distributed Capacity Technique 103

6.11 The Neutral State Technique 104

6.12 The Loose Coupling Technique 104

6.13 The Layered Defense Resilience Technique 104

6.14 The Internode Interaction Technique 113

6.15 The Complexity Technique 124

7 Case Studies 133

8 State Model 145

9 Organizational Factors 147

9.1 Loose Coupling in Organizational Systems 147

9.2 Observability Plus Decisions 147

9.3 Organizational Decision-Making 148

9.4 Informed Operator 149

10 Culture 151

10.1 The Culture Management Rule 151

10.2 The Cultural Change Rule 152

11 Executing Resilience 153

12 Governance 155

12.1 Inspecting in Quality 156

12.2 Independent Reviews 156

12.3 Governance and Culture 158

12.4 A Three-Tiered View of Technical Reviews 158

12.5 System-Level Review 159

12.6 Foreign Object Debris (FOD) 161

12.7 Responsibilities for Governance 162

12.8 Resilience Node 162

12.9 Program System Resilience Team 163

12.10 Program Management 163

13 Infrastructure 165

13.1 The Architecture of an Infrastructure System 165

13.2 Operational View 166

13.3 Organizational View 166

13.4 The Organization and Latent Conditions 167

13.5 The Integrated Product Team (IPT) Concept 168

13.6 Infrastructure Architecting 169

13.7 The Infrastructure as a System of Systems 169

13.8 Network-Based Infrastructures 171

14 Cost 173

14.1 Miracle on the Hudson 173

14.2 Space Shuttle Flights 173

14.3 New York Power Restoration 174

14.4 Summary 174

15 A Summary of Themes 175

References 180

16 A Final Word 181

16.1 The Challenges 183

Appendix A: Resilience of a Fire Protection System 185

Appendix B: Resilience of Metrolink 111 195

Appendix C: Resilience Architecting -- A Review 211

Index 243