Normal Accidents
Encyclopedia
Normal Accidents: Living with High-Risk Technologies is a 1984 book by Charles Perrow
, which provides a classic analysis of complex systems conducted from the point of view of a social scientist. It was the first, or one of the first, to "propose a framework for characterizing complex technological systems such as air traffic, marine traffic, chemical plants, dams, and especially nuclear power plant
s according to their riskiness". Perrow says that multiple and unexpected failures are built into society's complex systems.
"Normal" accidents (sometimes called system accident
s) are named that because they seem to start with something that seems ordinary or that happens all the time, almost always without causing great harm. Events which seem trivial cascade through the system in unpredictable ways to cause a large event with severe consequences:
The 1979 Three Mile Island accident
inspired Perrow's book, where a nuclear accident occurs, resulting from an unanticipated interaction of multiple failures in a complex system. TMI was an example of a normal accident because it was "unexpected, incomprehensible, uncontrollable and unavoidable".
Charles Perrow
Charles B. Perrow is an emeritus professor of sociology at Yale University and visiting professor at Stanford University. He is the author of several books and many articles on organizations, and is primarily concerned with the impact of large organizations on society.-Academic appointments:After...
, which provides a classic analysis of complex systems conducted from the point of view of a social scientist. It was the first, or one of the first, to "propose a framework for characterizing complex technological systems such as air traffic, marine traffic, chemical plants, dams, and especially nuclear power plant
Nuclear power plant
A nuclear power plant is a thermal power station in which the heat source is one or more nuclear reactors. As in a conventional thermal power station the heat is used to generate steam which drives a steam turbine connected to a generator which produces electricity.Nuclear power plants are usually...
s according to their riskiness". Perrow says that multiple and unexpected failures are built into society's complex systems.
"Normal" accidents (sometimes called system accident
System Accident
A system accident is an "unanticipated interaction of multiple failures" in a complex system. This complexity can either be technological or organizational, and often is both....
s) are named that because they seem to start with something that seems ordinary or that happens all the time, almost always without causing great harm. Events which seem trivial cascade through the system in unpredictable ways to cause a large event with severe consequences:
Normal Accidents contributed key concepts to a set of intellectual developments in the 1980s that revolutionized how we think about safety and risk. It made the case for examining technological failures as the product of highly interacting systems, and highlighted organizational and management factors as the main causes of failures. Technological disasters could no longer be ascribed to isolated equipment malfunction, operator error or acts of God.
The 1979 Three Mile Island accident
Three Mile Island accident
The Three Mile Island accident was a core meltdown in Unit 2 of the Three Mile Island Nuclear Generating Station in Dauphin County, Pennsylvania near Harrisburg, United States in 1979....
inspired Perrow's book, where a nuclear accident occurs, resulting from an unanticipated interaction of multiple failures in a complex system. TMI was an example of a normal accident because it was "unexpected, incomprehensible, uncontrollable and unavoidable".
Perrow concluded that the failure at Three Mile Island was a consequence of the system's immense complexity. Such modern high-risk systems, he realized, were prone to failures however well they were managed. It was inevitable that they would eventually suffer what he termed a 'normal accident'. Therefore, he suggested, we might do better to contemplate a radical redesign, or if that was not possible, to abandon such technology entirely.
See also
- List of books about nuclear issues
- Three Mile Island: A Nuclear Crisis in Historical Perspective