Quotes from book
Normal Accidents

Name: Normal Accidents
Author: Charles Perrow

Normal Accidents: Living with High-Risk Technologies is a 1984 book by Yale sociologist Charles Perrow, which provides a detailed analysis of complex systems from a sociological perspective. It was the first to "propose a framework for characterizing complex technological systems such as air traffic, marine traffic, chemical plants, dams, and especially nuclear power plants according to their riskiness". Perrow argues that multiple and unexpected failures are built into society's complex and tightly coupled systems. Such accidents are unavoidable and cannot be designed around.Perrow's argument, based on systemic features and human error, is that big accidents tend to escalate, and technology is not the problem, the organizations are. Each of these principles is still relevant today.

“Engineers speak of a “control loop,” in which the “man in the loop” is the problematical element. This is the human component in a series of sequentially interacting pieces of equipment that control or adjust a function. But when the pilot is suddenly and unexpectedly brought into the control loop (in other words, participates in decision making) as a result of (inevitable) equipment failure, he is disoriented. Long periods of passive monitoring make one unprepared to act in emergencies. The sudden appearance of several alarms, all there for safety reasons, leads to disorientation.”

Charles Perrow book Normal Accidents

Source: 1980s and later, Normal Accidents, 1984, p. 132

“Most normal accidents have a significant degree of incomprehensibility.”

Charles Perrow book Normal Accidents

Source: 1980s and later, Normal Accidents, 1984, p. 23

“It takes just the right combination of circumstances to produce a catastrophe, just as it takes the right combination of inevitable errors to produce an accident.”

Charles Perrow book Normal Accidents

Source: 1980s and later, Normal Accidents, 1984, p. 356

“As an organizational sociologist, I was interested in the system characteristics of large accidents, but the discipline also made me aware of the organizational genesis of male-made disasters.”

Charles Perrow book Normal Accidents

Source: 1980s and later, Normal Accidents, 1984, p. 4