Basic Guide to System Safety

BASIC GUIDE TO SYSTEM SAFETY Instructional guide applying “prevention through design” concepts to the design and redesign of work premises, tools, equipment, and processes Basic Guide to System Safety provides guidance on including prevention through design concepts within an occupational safety and health management system; through the application of these concepts, decisions pertaining to occupational hazards and risks can be incorporated into the process of design and redesign of work premises, tools, equipment, machinery, substances, and work processes, including their construction, manufacture, use, maintenance, and ultimate disposal or reuse. These techniques provide guidance for a life-cycle assessment and design model that balances environmental and occupational safety and health goals over the lifespan of a facility, process, or product. The updated Fourth Edition reflects current and emerging industry practices and approaches, providing an essential periodic review of the text to ensure its contents adequately meet the requirements of academia as well as other users in the occupational safety and health profession. The book also features a new chapter on Prevention through Design (PtD) and how it is linked to System Safety Engineering and Analysis. Topics covered in Basic Guide to System Safety include: System safety criteria, including hazard severity and probability, the hazard risk matrix, and system safety precedence System safety efforts, including closed-loop hazard tracking systems, accident risk assessments, and mishap, accident, and incident reporting Fault or functional hazard analysis, management oversight and risk trees, HAZOP and what-if analyses, and energy trace and barrier analysis (ETBA) Sneak circuit analysis, including types and causes of sneaks, input requirements, and advantages and disadvantages of the technique Providing essential fundamentals for readers who may not have a background or pre-requisite in the subject, Basic Guide to System Safety is an ideal introductory resource for the practicing safety and health professionals, along with advanced students taking industrial safety courses.

Table of Contents:
Preface to the Fourth Edition xiii Acknowledgments xvi Part I The System Safety Program 1 1 System Safety: An Overview 3 Background 3 The Difference Between Industrial Safety and System Safety (Leveson 2005) 7 System Safety and the Assessment of Risk 9 2 System Safety Concepts 15 Fundamentals 15 The System Safety Process 16 System Safety Criteria 18 Hazard Severity 18 Hazard Probability 19 The Hazard Risk Matrix 20 System Safety Precedence 22 Cost and Risk Acceptance 25 Quantitative Risk Assessment 28 Principles of Risk Management 29 Management Commitment 30 3 System Safety Program Requirements 32 The Safety Charter 32 Selling Safety to Management 33 The System Safety Effort 34 Life Cycle Phases and the System Safety Process 40 4 The Industrial Safety Connection 44 The Occupational Safety and Health Act 44 The Human Factors Element 46 Accident Prevention Through System Design 47 The Process of Task Analysis 52 The Job Safety Analysis and System Safety 53 Guidelines for Preparing a Job Safety Analysis 56 Signatures and Approvals 61 Attachments to the JSA Form 62 Changes in Hazard/Scope 62 System Safety: An Integral Part of the Overall Organization 62 5 Probability Theory and Statistical Analysis 66 Introduction 66 Probability 67 Statistics 70 Summary 73 Part II System Safety Analysis: Techniques and Methods 75 6 Preliminary Hazard Analysis 77 Introduction 77 The PHA Development Process 78 The Preliminary Hazard Analysis Report 84 PHA Example 84 System Description 85 System Operation 86 Preliminary Assessment 87 Evaluation of System Risk 87 Summary 96 7 Subsystem and System Hazard Analyses 97 Introduction 97 The SSHA Report 98 SSHA Example 99 System Description 100 Evaluation of Subsystem Hazard Risk 101 Summary 104 8 Operating and Support Hazard Analysis 105 Introduction 105 Ergonomics 105 When to Perform the O&SHA 108 O&SHA Example 110 Scope and Purpose of the Example O&SHA 110 Risk Assessment 110 Risk Assessment 1: 1B 112 Risk Assessment 2: 1A 113 Risk Assessment 3: 2B 114 Summary 116 9 Energy Trace and Barrier Analysis 117 Introduction 117 The Energy-Barrier Concept 117 Uses of the ETBA 118 Performing the ETBA 118 The ETBA Worksheet 119 ETBA Example 120 System Description 120 The ETBA 120 Summary 124 10 Failure Mode and Effect Analysis 126 Introduction 126 Types of FMEAs 126 Performing an FMEA 127 The FMEA Report 129 FMEA Example 131 System Component/Subassembly Description 131 Subsystem: Hoist Assembly 131 Component: Electric Hoist Motors and Controls 132 Component: Magnetorque Electric Load Brake 133 Component: Motor Brake Assembly 133 Component: Hoist Gear Reduction Assembly and Wire Rope Drum 133 Subsystem: Motor-Driven Power Wheel 134 Subsystem: Trolley Drive Assembly 134 Subsystem: Bridge Drive Assembly 134 Subsystem: Control Station 134 Subsystem: 1.5 Ton Crane Micro-Drive System 135 Passive Components 135 System Operation 136 Failure Mode(s) and Effect(s) 136 Evaluation of Potential Subsystem or Component Failures 138 Summary 141 11 Fault or Functional Hazard Analysis 142 Introduction 142 The FHA Process 143 FHA Example 144 System Description 144 The FHA Process 147 The FHA 147 Summary 148 12 Fault Tree Analysis 150 Introduction 150 Qualitative and Quantitative Reasoning 151 Constructing a Fault Tree 151 Fault Tree Symbols 153 FTA Examples 155 Probability Values and the Fault Tree 159 Summary 162 13 Management Oversight and Risk Tree 164 Introduction 164 The MORT Analytical Chart 165 MORT Use 166 The MORT Event Tree 167 Symbols 168 MORT Analysis Example 168 MORT Color Coding 170 Procedure for MORT Analysis 171 Summary 173 14 HAZOP and What-If Analyses 174 Introduction 174 Background 175 Definitions 175 Objectives 176 Team Members 176 Reference Data Requirements 177 The Concept of “Nodes” 177 Conducting the What-If Analysis 178 What-If Analysis Steps 179 The What-If Analysis Worksheet 180 Conducting the HAZOP Study 183 The HAZOP Worksheet 183 The Analysis Report 185 Summary 185 15 Special Use Analysis Techniques 188 Introduction 188 Sneak Circuit Analysis 189 Types and Causes of Sneaks 189 SCA Input Requirements 190 Advantages and Disadvantages of the SCA 192 Software Hazard Analysis 193 Types of SWHA Techniques 193 The Software Preliminary Hazard Analysis 193 Software Fault Hazard Analysis 194 Software Fault Tree (“Soft Trees”) 194 Emulation Analysis 195 Software System Hazard Analysis 195 Summary 195 16 Prevention Through Design and the Prevention of Incidents 197 Introduction 197 Incident Prevention Through Design and Planning 198 Historical Case Study – The Design of WW-II Bombers 198 Design Failures or Oversights Can Also Impact the Production Phase 200 Risk Mitigation 200 The Owner 201 The Design Team 203 The Construction Team 204 Safety Planning 205 The Safety Management Paradox 205 The Problem 206 The Solution 207 Summary 207 Epilogue 209 Acronyms and Abbreviations 211 Glossary of Terms 215 Bibliography 241 Index 243

About the Author :
Jeffrey W. Vincoli is currently Managing Consultant for Technical Services with Progressive Safety Management. In this position, he provides consultative support for clients in the subject areas of Compliance Assessments, Incident Investigations, and Expert Witness Services. Prior to joining Progressive Safety Management in 2019, Jeff worked as Director of Compliance for ESH&QA for a Bechtel affiliate company known as Welded Construction, a pipeline contractor based in Ohio.