E-Books: Basic Guide to System Safety, Third Edition HSSE WORLD

This book 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 life span of a facility, process, or product.

The new edition is expanded to include primer information on the use of safety assurance techniques in design and construction.

The third edition of the Basic Guide to System Safety contains all of the content of the previous editions, updated (where applicable) to reflect current industry practice.
The first edition of the Basic Guide to System Safety was the first volume issued in a series of Basic Guide books that focused on the topics of interest to the practicing occupational safety and/or health professional. Other Books in the Series include the Basic Guide to Environmental Compliance, Basic Guide to Accident Investigation and Loss Control, and Basic Guide to Industrial Hygiene. Each book has been designed to provide the reader with a fundamental understanding of the subject and attempt to foster a desire for additional information and training. In addition to updated content of the previous editions, the revised third edition of the Basic Guide to System Safety introduces some system safety concepts not previously discussed to further expand upon the basic knowledge that is the cornerstone of the Basic Guide Series. In this regard, the third edition contains a discussion on the concept of Design for Safe Construction where the methods and techniques associated with the system safety discipline can be effectively utilized to identify, analyze, eliminate, or control system hazards during the design phase of a construction project.

As with all analytical methods and techniques presented in this text, it is suggested that the concept of design for construction safety has definite application to general industry operations.

Also, information on the use of the various methods and techniques associated with the use of system safety has been expanded in the third edition to include guidance on the evaluation and verification of compliance efforts following the implementation of system safety analysis. This additional information will attempt to close the loop on the effective use of system safety analysis in the industrial safety environment.

The idea or concept of system safety can be traced to the missile production industry of the late 1940s. It was further defined as a separate discipline by the late 1950s (Roland and Moriarty 1983) and early 1960s, used primarily by the missile, aviation, and aerospace communities. Prior to the 1940s, system designers and engineers relied predominantly on a trial-and-error method of achieving safe design. This approach was somewhat successful in an era when system complexity was relatively simple compared with those of subsequent development. For example, in the early days of the aviation industry, this process was often referred to as the “fly-fix-fly” approach to
design problems (Roland and Moriarty 1983; Stephenson 1991) or, more accurately, “safety-by-accident.” Simply stated, an aircraft was designed based upon existing or known technology. It was then flown until problems developed or, in the worst case, it crashed (Figure 1.1). If design errors were determined as the cause (as opposed to human, or “pilot” error), then the design problems would be fixed and the aircraft would fly again. Obviously, this method of after-the-fact design safety worked well when aircraft flew low and slow and were constructed of wood, wire, and cloth.
However, as systems grew more complex and aircraft capabilities such as airspeed and maneuverability increased, so did the likelihood of devastating results from a failure of the system or one of its many subtle interfaces. This is clearly demonstrated in the early days of the aerospace era (the 1950s and 1960s). As the industry began to develop jet-powered aircraft and space and missile systems, it quickly became clear that engineers

The Contents of Basic Guide to System Safety, Third Edition

PART I THE SYSTEM SAFETY PROGRAM 1
- 1 System Safety: An Overview 3
  - Background / 3
  - The Difference Between Industrial Safety and System Safety / 7
  - System Safety and the Assessment of Risk / 8
- 2 System Safety Concepts 15
  - Fundamentals / 15
  - The System Safety Process / 16
  - System Safety Criteria / 18
  - Hazard Severity / 18
  - Hazard Probability / 18
  - The Hazard Risk Matrix / 19
  - System Safety Precedence / 20
  - Cost and Risk Acceptance / 24
  - Quantitative Risk Assessment / 25
  - Principles of Risk Management / 27
  - Management Commitment / 27
- 3 System Safety Program Requirements 29
  - The Safety Charter / 29
  - Selling Safety to Management / 30
  - The System Safety Effort / 31
  - Closed-Loop Hazard Tracking System / 32
  - Accident Risk Assessment / 33
  - Mishap/Accident/Incident Reporting / 33
  - Facility Inspection Reports / 36
  - System Safety Analyses / 36
  - Life Cycle Phases and the System Safety Process / 36
  - Concept Phase / 37
  - Design Phase / 37
  - Production Phase / 37
  - Operations Phase / 39
  - Disposal Phase / 39
- 4 The Industrial Safety Connection 41
  - The Occupational Safety and Health Act / 41
  - The Human Factors Element / 43
  - Accident Prevention Through System Design / 44
  - The Process of Task Analysis / 47
  - The Job Safety Analysis and System Safety / 48
  - Guidelines for Preparing a Job Safety Analysis / 50
  - Signatures and Approvals / 56
  - Changes in Hazard/Scope / 56
  - System Safety: an Integral Part of the Overall Organization / 57
- 5 Probability Theory and Statistical Analysis 61
  - Introduction / 61
  - Probability / 62
  - Statistics / 64
  - Summary / 67
PART II SYSTEM SAFETY ANALYSIS: TECHNIQUES AND METHODS 69
- 6 Preliminary Hazard Analysis 71
  - Introduction / 71
  - The PHA Development Process / 72
  - The PHA Report / 78
  - PHA Example / 78
  - System Description / 79
  - System Operation / 80
  - Preliminary Assessment / 81
  - Evaluation of System Risk / 81
  - Summary / 90
- 7 Subsystem and System Hazard Analyses 91
  - Introduction / 91
  - The Subsystem Hazard Analysis Report / 92
  - SSHA Example / 93
  - System Description / 93
  - Evaluation of Subsystem Hazard Risk / 95
  - Summary / 98
- 8 Operating and Support Hazard Analysis 99
  - Introduction / 99
  - Ergonomics / 99
  - When to Perform the O&SHA / 101
  - O&SHA Example / 103
  - Scope and Purpose of the Example O&SHA / 103
  - Risk Assessment / 104
  - Risk Assessment 1: 1B / 106
  - Risk Assessment 2: 1A / 107
  - Risk Assessment 3: 2B / 107
  - Summary / 109
- 9 Energy Trace and Barrier Analysis 111
  - Introduction / 111
  - The Energy–Barrier Concept / 111
  - Uses of the ETBA / 112
  - Performing the ETBA / 112
  - The ETBA Worksheet / 113
  - ETBA Example / 114
  - System Description / 114
  - The ETBA / 114
  - Summary / 118
- 10 Failure Mode and Effect Analysis 119
  - Introduction / 119
  - Types of FMEAs / 119
  - Performing an FMEA / 120
  - The FMEA Report / 121
  - FMEA Example / 124
  - System Component/Subassembly Description / 124
  - System Operation / 128
  - Failure Mode(s) and Effect(s) / 128
  - Evaluation of Potential Subsystem or Component Failures / 129
  - Summary / 132
- 11 Fault or Functional Hazard Analysis 135
  - Introduction / 135
  - The FHA Process / 136
  - FHA Example / 137
  - System Description / 137
  - The FHA Process / 139
  - The FHA / 141
  - Summary / 143
- 12 Fault Tree Analysis 145
  - Introduction / 145
  - Qualitative and Quantitative Reasoning / 146
  - Constructing a Fault Tree / 146
  - Fault Tree Symbols / 147
  - FTA Examples / 150
  - Probability Values and the Fault Tree / 153
  - Summary / 156
- 13 Management Oversight and Risk Tree 157
  - Introduction / 157
  - The MORT Analytical Chart / 158
  - MORT Use / 159
  - The MORT Event Tree / 160
  - Symbols / 160
  - MORT Analysis Example / 161
  - MORT Color Coding / 163
  - Procedure for MORT Analysis / 165
  - Summary / 165
- 14 HAZOP and What-If Analyses 167
  - Introduction / 167
  - Background / 168
  - Definitions / 168
  - Objectives / 169
  - Team Members / 169
  - Reference Data Requirements / 169
  - The Concept of “Nodes” / 170
  - Conducting the What-If Analysis / 171
  - What-If Analysis Steps / 171
  - The What-If Analysis Worksheet / 173
  - Conducting The HAZOP Study / 175
  - The HAZOP Worksheet / 175
  - The Analysis Report / 176
  - Summary / 177
- 15 Special Use Analysis Techniques 179
  - Introduction / 179
  - Sneak Circuit Analysis / 180
  - Types and Causes of Sneaks / 180
  - SCA Input Requirements / 181
  - Advantages and Disadvantages of the SCA / 181
  - Software Hazard Analysis / 183
  - Types of SWHA Techniques / 183
  - Summary / 185
  - Epilogue 18
Appendix A Sources of Additional Information/Training 189
Appendix B Acronyms and Abbreviations 195
GLOSSARY OF TERMS 199
BIBLIOGRAPHY 223
INDEX 225