Download The ETTO Principle: Efficiency-Thoroughness Trade-Off by Erik Hollnagel PDF

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B. ) The example of the circular-saw operator is found on page 94 of H. W. Heinrich (1931), Industrial Accident Prevention (New York: McGraw-Hill). This book pioneered the practical study of industrial safety, and introduced a number of models and methods, several of which are still in use. Mr Heinrich was an Assistant Superintendent of the Engineering and Inspection Division of Travelers Insurance Company in Hartford, CT, and the book was based on his extensive practical experience in accident investigation.

It is likewise necessary to be thorough both to make sure that we do things in the right way, so that we can achieve what we intend, and to avoid adverse consequences 舑 incidents and accidents. One simple reason why thoroughness is needed is that accidents and incidents invariably will reduce the efficiency, for instance because the system has to be stopped for shorter or longer periods of time, parts repaired or replaced, verified for use again, etc. More concretely, an efficiency-thoroughness trade-off can happen for one or more of the following reasons: 舦 Limited availability of required resources, especially limited time or uncertainty about how much time is available.

Table of Contents List of Figures List of Tables Prologue About the Style of this Book Sources for Prologue Chapter 1: The Need to Understand Why Things Go Wrong Safety Requires Knowledge A Need for Certainty Explaining Something that is Out of the Ordinary The Stop Rule A Need for Simple Explanations The ETTO Principle The ETTO Principle in Practice Changing Views A Note on Terminology Sources for Chapter 1 Chapter 2: From Rationality to ETTOing The Rational Human Time to Think, and Time to Do ETTO Redefined Feed the Birds The Value of Planning Information Pull and Information Push Descriptive Decision Rules Judgement Heuristics Work Related ETTO Rules Individual (Psychological) ETTO Rules Collective (Organisational) ETTO Rules Sources for Chapter 2 Chapter 3: Explaining Human Irrationality Satisficing Satisficing versus Sacrificing Muddling Through Recognition Primed Decision-Making The Use of Schemata Speed舑Accuracy Trade-Off Time舑Reliability Correlation Information Input Overload ETTO as a Principle of Rationality Tractable and Intractable Systems Sources for Chapter 3 Chapter 4: Efficiency-Thoroughness Trade-Off in Practice The Choice of Efficiency Ice Problems at Gardemoen The Leaking Barrel London Bombings Full Protection not Feasible The Challenges of Publishing Aeronautical Data Incorrect Chemotherapy Treatment A Reverse Fuel Situation The Loss of M/V Estonia Avoiding Collision at Sea Mission to Mars Concluding Remarks Sources for Chapter 4 Chapter 5: The Usefulness of Performance Variability Underspecified Systems The Need of Performance Variability Sources and Types of Performance Variability Approximate Adjustments Failures without Malfunctions About 舖Human Error Mechanisms舗 Performance Variability and Risk The Dark Matter Sources for Chapter 5 Chapter 6: ETTOs of the Past Accident Philosophies and the ETTO Principle The Root Cause Resultant and Emergent Effects Limitations of Causal Analyses ETTO and Learning from Experience Looking for ETTOs in Practice Collaborative ETTO What Really Happened?