Product Description

Normal Accidents analyzes the social side of technological risk. Charles Perrow argues that the conventional engineering approach to ensuring safety--building in more warnings and safeguards--fails because systems complexity makes failures inevitable. He asserts that typical precautions, by adding to complexity, may help create new categories of accidents. (At Chernobyl, tests of a new safety system helped produce the meltdown and subsequent fire.) By recognizing two dimensions of risk--complex versus linear interactions, and tight versus loose coupling--this book provides a powerful framework for analyzing risks and the organizations that insist we run them.

The first edition fulfilled one reviewer's prediction that it "may mark the beginning of accident research." In the new afterword to this edition Perrow reviews the extensive work on the major accidents of the last fifteen years, including Bhopal, Chernobyl, and the Challenger disaster. The new postscript probes what the author considers to be the "quintessential 'Normal Accident'" of our time: the Y2K computer problem.

Product Details

• Amazon Sales Rank: #13206 in Books
• Published on: 1999-09-27
• Original language: English
• Binding: Paperback
• 386 pages

From Amazon.com
Hang a curtain too close to a fireplace and you run the risk of setting your house ablaze. Drive a car on a pitch-black night without headlights, and you dramatically increase the odds of smacking into a tree.

These are matters of common sense, applied to simple questions of cause and effect. But what happens, asks systems-behavior expert Charles Perrow, when common sense runs up against the complex systems, electrical and mechanical, with which we have surrounded ourselves? Plenty of mayhem can ensue, he replies. The Chernobyl nuclear accident, to name one recent disaster, was partially brought about by the failure of a safety system that was being brought on line, a failure that touched off an unforeseeable and irreversible chain of disruptions; the less severe but still frightening accident at Three Mile Island, similarly, came about as the result of small errors that, taken by themselves, were insignificant, but that snowballed to near-catastrophic result.

Only through such failures, Perrow suggests, can designers improve the safety of complex systems. But, he adds, those improvements may introduce new opportunities for disaster. Looking at an array of real and potential technological mishaps--including the Bhopal chemical-plant accident of 1984, the Challenger explosion of 1986, and the possible disruptions of Y2K and genetic engineering--Perrow concludes that as our technologies become more complex, the odds of tragic results increase. His treatise makes for sobering and provocative reading. --Gregory McNamee

Review
[Normal Accidents is] a penetrating study of catastrophes and near catastrophes in several high-risk industries. Mr. Perrow ... writes lucidly and makes it clear that 'normal' accidents are the inevitable consequences of the way we launch industrial ventures... An outstanding analysis of organizational complexity. -- John Pfeiffer The New York Times [Perrow's] research undermines promises that 'better management' and 'more operator training' can eliminate catastrophic accidents. In doing so, he challenges us to ponder what could happen to justice, community, liberty, and hope in a society where such events are normal. -- Deborah A. Stone Technology Review

Review
[Normal Accidents is] a penetrating study of catastrophes and near catastrophes in several high-risk industries. Mr. Perrow ... writes lucidly and makes it clear that `normal' accidents are the inevitable consequences of the way we launch industrial ventures.... An outstanding analysis of organizational complexity.
(John Pfeiffer The New York Times )

[Perrow's] research undermines promises that `better management' and `more operator training' can eliminate catastrophic accidents. In doing so, he challenges us to ponder what could happen to justice, community, liberty, and hope in a society where such events are normal.
(Deborah A. Stone Technology Review )

Customer Reviews

Living With High-Risk Conclusions
I have been mulling over this review for a while now, and am still undecided on the correct rating to award this book. On the one hand Perrow offers some genuine insight into systems safety, but frequently does not understand the technicalities of the systems (or occasionally their operators) well enough to make informed decisions and recommendations. In more egregious cases he comes to conclusions that are guaranteed to reduce safety (as when he argues that supertankers should be run by committee, and the usefulness of the Captain is no more) or are merely the cherished liberal opinions of an Ivy League sociologist (he teaches at Yale) as when he argues for unilateral nuclear disarmament, government guaranteed income plans, and heroin maintenance (distribution) plans for addicts "to reduce crime." In the case of disarmament, remember this was written during the early 1980s while the Soviet Union was still a huge threat...complete nuclear disarmament would have resulted in fewer US nuclear accidents, but would NOT have made us safer as we would have been totally vulnerable to intentional nuclear attack. He has great personal animosity toward Ronald Reagan, and makes inflammatory statements in the mining section that mining safety regulations would surely be weakened by Reagan, causing many more accidents and deaths. Later in the same section, though, he concludes that mining is inherently dangerous, and no amount of regulation can make it safe. So which is it? Any of this is, at very best, folly, but regardless of political bent (he is a self avowed "leftist liberal") has absolutely no place in a book ostensibly on safety systems. As such I think portions of this book show what is so wrong in American academia today: even genuinely excellent research can be easily spoiled when the conclusions are known before the research is started. This is one of the many reasons that physical scientists scorn the social sciences, and it doesn't have to be this way.

Having said all that there IS a wealth of good information and insight in this book when Perrow sticks to systems and their interactions. The book contains the finest analysis commercially available of the Three Mile Island near-disaster, and his insight about how to improve safety in nuclear plants was timely when the book was written in 1984, though many improvements have been made since then.

Speaking as a commercial airline pilot, I feel his conclusions and observations about aircraft safety were generally true at the time of printing in 1984, but now are miserably out of date. (The same is true of the Air Traffic Control section.) I believe that he generally has a good layman's grasp of aviation, so I am willing to take it as a given that he has a knowledgeable layman's comprehension of the other systems discussed. As an aside, he never gets some of the technicalities quite right. For instance, he constantly uses the term 'coupling' incorrectly in the engineering sense; this is particularly objectionable in the aviation system where it has a very specific meaning to aeronautical engineers and pilots.

The section on maritime accidents and safety is superbly written. Here I am not an expert, but there seems to be a high degree of correlation with the aviation section. His section on "Non Collision Course Collisions" by itself makes this book a worthwhile read. He presents very compelling information and reasoning until the very end of the section, at which point he suggests that since ships are now so big, large ships (especially supertankers) essentially should have no Captain, but should be run by committee. This is an invalid conclusion, and he offers no evidence or substantial argument to support that idea. Clearly, it is an idea hatched in his office and not on a ship (or plane.) There always needs to be a person in a place of ultimate authority in fast moving, dynamic systems, or the potential exists to have crew members begin to work at direct odds with each other, making a marginal situation dangerous. Ironically, in the very same part of the discussion where he concludes that there should be no Captain, he has hit upon the key to the problem. He mentions that he was pleased to see that some European shippers were now training their crews together as a team, and that he expected this to lower accident rates. He is, in fact, exactly right about that. Airlines now have to train crews in Crew Resource Management (CRM) in which each member of the crew has the right and obligation to speak up if they notice anything awry in the operation of their aircraft, and the Captain makes it a priority to listen to the input of others, as everyone has a different set of concerns and knowledge. In this way, the Captain becomes much less dictatorial, and becomes more of a final decision maker after everyone has had their say. It IS critical, though, to maintain someone in command, as there is no time to assemble a staff meeting when a ship is about to run aground, or a mid-air collision is about to occur. Many other well documented studies and books have come to this conclusion, and in the airline industry since CRM was introduced the accident rate has decreased dramatically.

Overall, if you have a desire to understand high risk systems, this book has a lot of good information in it; however it is woefully out of date and for that reason among others, I can only recommend it with reservations. A better and much more contemporary introductory book on the subject is 'Inviting Disaster' by James R. Chiles. Remember, this book was written over twenty years ago, and much has changed since then. There is knowledge to be gleaned here, but you have to be prepared to sort the wheat from the chaff.

Living With High-Risk Conclusions
I have been mulling over this review for a while now, and am still undecided on the correct rating to award this book. On the one hand Perrow offers some genuine insight into systems safety, but frequently does not understand the technicalities of the systems (or occasionally their operators) well enough to make informed decisions and recommendations. In more egregious cases he comes to conclusions that are guaranteed to reduce safety (as when he argues that supertankers should be run by committee, and the usefulness of the Captain is no more) or are merely the cherished liberal opinions of an Ivy League sociologist (he teaches at Yale) as when he argues for unilateral nuclear disarmament, government guaranteed income plans, and heroin maintenance (distribution) plans for addicts "to reduce crime." In the case of disarmament, remember this was written during the early 1980s while the Soviet Union was still a huge threat...complete nuclear disarmament would have resulted in fewer US nuclear accidents, but would NOT have made us safer as we would have been totally vulnerable to intentional nuclear attack. He has great personal animosity toward Ronald Reagan, and makes inflammatory statements in the mining section that mining safety regulations would surely be weakened by Reagan, causing many more accidents and deaths. Later in the same section, though, he concludes that mining is inherently dangerous, and no amount of regulation can make it safe. So which is it? Any of this is, at very best, folly, but regardless of political bent (he is a self avowed "leftist liberal") has absolutely no place in a book ostensibly on safety systems. As such I think portions of this book show what is so wrong in American academia today: even genuinely excellent research can be easily spoiled when the conclusions are known before the research is started. This is one of the many reasons that physical scientists scorn the social sciences, and it doesn't have to be this way.

Having said all that there IS a wealth of good information and insight in this book when Perrow sticks to systems and their interactions. The book contains the finest analysis commercially available of the Three Mile Island near-disaster, and his insight about how to improve safety in nuclear plants was timely when the book was written in 1984, though many improvements have been made since then.

Speaking as a commercial airline pilot, I feel his conclusions and observations about aircraft safety were generally true at the time of printing in 1984, but now are miserably out of date. (The same is true of the Air Traffic Control section.) I believe that he generally has a good layman's grasp of aviation, so I am willing to take it as a given that he has a knowledgeable layman's comprehension of the other systems discussed. As an aside, he never gets some of the technicalities quite right. For instance, he constantly uses the term 'coupling' incorrectly in the engineering sense; this is particularly objectionable in the aviation system where it has a very specific meaning to aeronautical engineers and pilots.

The section on maritime accidents and safety is superbly written. Here I am not an expert, but there seems to be a high degree of correlation with the aviation section. His section on "Non Collision Course Collisions" by itself makes this book a worthwhile read. He presents very compelling information and reasoning until the very end of the section, at which point he suggests that since ships are now so big, large ships (especially supertankers) essentially should have no Captain, but should be run by committee. This is an invalid conclusion, and he offers no evidence or substantial argument to support that idea. Clearly, it is an idea hatched in his office and not on a ship (or plane.) There always needs to be a person in a place of ultimate authority in fast moving, dynamic systems, or the potential exists to have crew members begin to work at direct odds with each other, making a marginal situation dangerous. Ironically, in the very same part of the discussion where he concludes that there should be no Captain, he has hit upon the key to the problem. He mentions that he was pleased to see that some European shippers were now training their crews together as a team, and that he expected this to lower accident rates. He is, in fact, exactly right about that. Airlines now have to train crews in Crew Resource Management (CRM) in which each member of the crew has the right and obligation to speak up if they notice anything awry in the operation of their aircraft, and the Captain makes it a priority to listen to the input of others, as everyone has a different set of concerns and knowledge. In this way, the Captain becomes much less dictatorial, and becomes more of a final decision maker after everyone has had their say. It IS critical, though, to maintain someone in command, as there is no time to assemble a staff meeting when a ship is about to run aground, or a mid-air collision is about to occur. Many other well documented studies and books have come to this conclusion, and in the airline industry since CRM was introduced the accident rate has decreased dramatically.

Overall, if you have a desire to understand high risk systems, this book has a lot of good information in it; however it is woefully out of date and for that reason among others, I can only recommend it with reservations. A better and much more contemporary introductory book on the subject is 'Inviting Disaster' by James R. Chiles. Remember, this book was written over twenty years ago, and much has changed since then. There is knowledge to be gleaned here, but you have to be prepared to sort the wheat from the chaff.

Altogether a fascinating and informative book
Wow. This is an incredible book. I have to admit, though, that I had some difficulty getting into Normal Accidents. There seemed an overabundance of detail, particularly on the nuclear industry's case history of calamity. This lost me, since I'm not familiar with the particulars of equipment function and malfunction. The book was mentioned, however, by two others of a similar nature and mentioned with such reverence, that after I had finished both, I returned to Perrow's book, this time with more success.

Professor Perrow is a PhD in sociology (1960) who has taught at Yale University Department of Sociology since 1981 and whose research focus has been human/technology interactions and the effects of complexity in organizations. (His most recent publication is the The AIDS disaster : the Failure of Organizations in New York and the Nation, 1990.)

In Normal Accidents, he describes the failures that can arise "normally" in systems, ie. those problems that are expected to arise and can be planned for by engineers, but which by virtue of those planned fail-safe devices, immeasurably complicate and endanger the system they are designed to protect. He describes a variety of these interactions, clarifying his definitions by means of a table (p. 88), and a matrix illustration (p. 97). Examples include systems that are linear vs complex, and loosely vs tightly controlled. These generally arise through the interactive nature of the various components the system itself. According to the matrix, an illustration of a highly linear, tightly controlled system would be a dam. A complex, tightly controlled system would be a nuclear plant, etc.

The degree to which failures may occur varies with each type of organization, as does the degree to which a recovery from such a failure is possible. As illustrations, the author describes failures which have, or could have, arisen in a variety of settings: the nuclear industry, maritime activities, the petrochemical industry, space exploration, DNA research and so on.

The exciting character of the stories themselves are worth the reading; my favorite, and one I had heard before, is the loss of an entire lake into a salt mine. More important still is the knowledge that each imparts. Perrow makes abundantly apparent by his illustrations the ease with which complex systems involving humans can fail catastrophically. (And if Per Bak and others are correct, almost inevitably).

Probably the most significant part of the work is the last chapter. After discussing the fallibility of systems that have grown increasingly complex, he discusses living with high risk systems, particularly why we are and why it should change. In a significant statement he writes, "Above all, I will argue, sensible living with risky systems means keeping the controversies alive, listening to the public, and recognizing the essentially political nature of risk assessment. Unfortunately, the issue is not risk, but power; the power to impose risks on the many for the benefit of the few (p. 306)," and further on, "Risks from risky technologies are not borne equally by the different social classes [and I would add, countries]; risk assessments ignore the social class distribution of risk (p. 310)." How true. "Quo Bono?" as the murder mystery writers might say; "Who benefits?" More to the point, and again with that issue in mind, he writes "The risks that made our country great were not industrial risks such as unsafe coal mines or chemical pollution, but social and political risks associated with democratic institutions, decentralized political structures, religious freedom and plurality, and universal suffrage (p. 311)." Again, very true.

Professor Perrow examines the degrees of potential danger from different types of system and suggests ways of deciding which are worth it to society to support and which might not be. These include categorizing the degree and the extent of danger of a given system to society, defining the way these technologies conflict with the values of that society, determining the likelihood that changes can be made to effectively alter the dangerous factors through technology or training of operators, and the possibility of placing the burden of spill-over costs on the shoulders of the institutions responsible. The latter might conceivably lead to corrective changes, either by the institutions themselves in order to remain profitable or by consumers through purchasing decisions.

The bibliography for the book is quite extensive and includes a variety of sources. These include not only popular books and publications on the topics of individual disasters, but government documents, research journals, and industry reports as well. I did not find any reference to the Johnstown flood, my particular favorite dam burst story, but there are a wide variety of references to chose from should someone wish to do their own research on the topic.

Altogether a fascinating and informative book.