In 1997, Reason published yet another hit - "MANAGING THE RISKS OF ORGANIZATIONAL ACCIDENTS". This book, as Reason puts it, ... aimed at the "real people" and especially those whose daily business is to think about, and manage or regulate, the risk of hazardous technologies - like commercial aviation - our business.

Yes, this book is meant for the bosses, the Chairman, the CEO, all the Presidents, Executive Vice Presidents, Senior Vice Presidents and last but not least --- (if you are in the air transport business) --- the pilots in the flight deck - as the "Sharp End Operators" and the "Last Line Defenders" to fight against of all the possible latent errors and threats made long before we step into the flightdeck, but expect us to put a stop to any possible mishap from happening when the situation arises!

Professor Reason uses his now popular "Swiss Cheese" Model of Defence to explain the nature of those "latent threats" or "latent errors" lurking in our air transport organization (and others), waiting to spring on us when the time and opportunity present themselves.

Reason argues that highly hazardous technological industry like the air transport industry, (nuclear and chemical plants as well etc.) are usually protected with layers of strong defences..

Let me try to illustrate; let's say we have a lot of hazards to contain on the left hand side of this page, and the losses (if the hazards are not contained and causing accidents) are on the right hand side of this same page. Our defences are like layers of steel plates erected between the hazards and losses to protect them from meeting (liken to be like a light beam shining through).

In real life, these steel plates are both "hardware" and "software". Hardware are, for example better designed modern airplanes with many safety features incorporated from experiences gained over the last few decades of air transport operations, better human-engineering to prevent human factor related errors from being committed. Having better equipment to forecast weather better, better equipment to detect and forewarn the pilots of impending collision with other traffic or terrain etc.

Software, on the other hand, are people themselves, plus philosophy, policy and enforcing procedures to promote safety, implementing safety rules and regulations and practices to guard against accidents from happening.

Well and good, to be fair, all these work pretty well most of the time. That's why you don't get to see many air disasters, nuclear plant accidents, or offshore oil rig disasters very often. Reason, however, argues these "steel plates" are not hole-proof, there are in fact, full of "holes", caused by latent threats and errors, such as company pressure, tight schedules, awkward rules that are hard to follow, long working hours, inadequate rest, lack of on-going trainings, or lack of safety awareness practices, impractical fuel policy etc.

These "holes" in the steel plates expand or shrink depend on prevailing conditions. The holes are "latent threats and errors" built-in to the system, they alone will not cause accidents (not all the plates) but when coupled with some "active failures", (the remaining plates) such as human errors, lapses or slips in the system, in the right place and at the right time, the imaginary light from the left hand "hazards" side, will shine through these porous steel plates and light up the right hand "losses" side, an accident happens! But when it does happen, it is certainly a "Big Bang" headline news, which is usually coupled with heavy human death toll and colossal hardware losses.

Professor Reason deals specifically with the latent threats rather than the active failures, because, as in the Swiss Cheese Model, all you need to do is to make one of the steel plate hole-proof and the error chain is broken, thus preventing a disaster from occurring. Simple as that. Active failures will be dealt with elsewhere..

To sum up, this book covers hazards, defences and losses in all the hazardous high technology industries, it also points out reasons why sometimes these defences are penetrated and defeated. In fact Reason says some of these defences are themselves dangerous! He also talks of the human contribution to the breakdown in the defences, even maintenance, the very reason for maintenance is to ensure safety and reliability of the systems we built, itself can cause accidents if negligence seeps in. He offers practical guides to error management, and finally, how to engineer a safety culture to prevent "Big Bangs" from happening.

A highly recommended reference for those who take flight safety business seriously.