Bow Ties in Risk Management

AN AUTHORITATIVE GUIDE THAT EXPLAINS THE EFFECTIVENESS AND IMPLEMENTATION OF BOW TIE ANALYSIS, A QUALITATIVE RISK ASSESSMENT AND BARRIER MANAGEMENT METHODOLOGY
From a collaborative effort of the Center for Chemical Process Safety (CCPS) and the Energy Institute (EI) comes an invaluable book that puts the focus on a specific qualitative risk management methodology - bow tie barrier analysis. The book contains practical advice for conducting an effective bow tie analysis and offers guidance for creating bow tie diagrams for process safety and risk management. Bow Ties in Risk Management clearly shows how bow tie analysis and diagrams fit into an overall process safety and risk management framework.
Implementing the methods outlined in this book will improve the quality of bow tie analysis and bow tie diagrams across an organization and the industry. This important guide:

• Explains the proven concept of bow tie barrier analysis for the preventing and mitigation of incident pathways, especially related to major accidents
• Shows how to avoid common pitfalls and is filled with real-world examples
• Explains the practical application of the bow tie method throughout an organization
• Reveals how to treat human and organizational factors in a sound and practical manner
• Includes additional material available online

Although this book is written primarily for anyone involved with or responsible for managing process safety risks, this book is applicable to anyone using bow tie risk management practices in other safety and environmental or Enterprise Risk Management applications. It is designed for a wide audience, from beginners with little to no background in barrier management, to experienced professionals who may already be familiar with bow ties, their elements, the methodology, and their relation to risk management.
The missions of both the CCPS and EI include developing and disseminating knowledge, skills, and good practices to protect people, property and the environment by bringing the best knowledge and practices to industry, academia, governments and the public around the world through collective wisdom, tools, training and expertise. The CCPS has been at the forefront of documenting and sharing important process safety risk assessment methodologies for more than 30 years. The EI's Technical Work Program addresses the depth and breadth of the energy sector, from fuels and fuels distribution to health and safety, sustainability and the environment. The EI program provides cost-effective, value-adding knowledge on key current and future international issues affecting those in the energy sector.

List of Tables ix
List of Figures xi
Acronyms and Abbreviations xiii
Glossary xv
Acknowledgments xxiii
Online Materials Accompanying this Book xxvii
Preface xxix
1 INTRODUCTION 1
1. 1 Purpose 1
1. 2 Scope and Intended Audience 1
1. 3 Organization of this Concept Book 2
1. 4 Introduction to the Bow Tie Concept 4
1. 5 Conclusions 12
2 THE BOW TIE MODEL 15
2. 1 Bow Tie Model Elements 15
2. 2 Hazard 17
2. 3 Top Event 20
2. 4 Consequences 24
2. 5 Threats 27
2. 6 Barriers 32
2. 7 Degradation actors and Degradation Controls 45
2. 8 Conclusions 51
3 BOW TIE DEVELOPMENT 53
3. 1 Rationale for Bow Tie Development 53
3. 2 Bow Tie workshop 53
3. 3 Postow Tie Workshop Activities and Quality Checks 64
Conclusions 51
4 ADDRESSING HUMAN FACTORS IN BOW TIE ANALYSIS 69
4. 1 Human and Organiational Factors Fundamentals 69
4. 2 Standard and MultiLevel Bow Tie Approaches 74
4. 3 Human and Organiational Factors as a Barrier or Degradation Control 80
4. 4 Validating Human Performance in Barriers and Degradation Controls 84
4. 5 Quantifying Human Reliability in Bow Ties 86
4. 6 Conclusions 86
5 PRIMARY USES OF BOW TIES 89
5. 1 Primary Use Examples 89
5. 2 Linking Bow Ties to the Risk Management System 89
5. 3 Communication of Major Accident Scenarios and Degradation Controls 94
5. 4 Use of Bow Ties in Design and Operations 101
5. 5 Identification of Safety Critical Information 107
5. 6 Conclusions 113
6 BARRIER MANAGEMENT PROGRAM 115
6. 1 Barrier Management Strategy 115
6. 2 Barrier and Degradation Control Management Program 118
6. 3 Organizational Learning 127
6. 4 Conclusions 128
7 ADDITIONAL USES OF BOW TIES 131
7. 1 Additional Use Examples 131
7. 2 Linking Bow Ties to HAZOP, LOPA and SIL 131
7. 3 Integrating Bow Ties into ALARP Demonstrations 134
7. 4 Operationalizing Bow Ties (MOPO / SOOB) 135
7. 5 Incident Investigation using Bow Ties 139
7. 6 Real-time Dashboards using Bow Ties 142
7. 7 Barrier and Degradation Control Verification 143
7. 8 Bow Tie Chaining 144
7. 9 Enterprise-wide Analysis and Window on Systemic Risks 146
7. 10 Conclusions 147
APPENDIX A - SOFTWARE TOOLS 149
Software used for Bow Tie Diagrams 149
APPENDIX B - CASE STUDY 153
Introduction 153
Volatile Hydrocarbons under Pressure in a Pipeline 153
APPENDIX C - MULTI-LEVEL BOW TIES 161
Multilevel Bow Tie for Tank Overfill 161
References 171
Index 177