The book argues that many large-scale failures, such as plane crashes or nuclear accidents, are not the result of a single catastrophic event, but rather the accumulation of a series of small failures or errors that ultimately lead to disaster. These failures can occur in any complex system, whether it be an airplane, a nuclear power plant, or a hospital.
According to Dekker, these failures are often the result of a "drift into failure," where small deviations from normal operation go unnoticed and eventually lead to a catastrophic event. These deviations can be caused by a variety of factors, such as human error, equipment malfunction, or organisational problems.
Dekker argues that in order to prevent drift into failure, it is important to focus on the root causes of these small deviations and address them before they become larger problems. He also emphasises the importance of creating a culture of safety within organisations, where employees feel comfortable reporting errors and potential problems without fear of retribution.
One example of drift into failure that Dekker discusses in the book is the Exxon Valdez oil spill. On March 24, 1989, the Exxon Valdez oil tanker ran aground on a reef in Alaska, spilling millions of gallons of oil into the ocean. According to Dekker, the disaster was not the result of a single event, but rather the accumulation of a series of small failures and errors.
For instance, the captain of the tanker, Joseph Hazelwood, was intoxicated at the time of the accident. However, this was not the root cause of the disaster. Rather, it was the result of a culture within the company that did not prioritise safety and allowed Hazelwood to continue working despite his alcohol abuse. Additionally, there were problems with the ship's navigation equipment and the crew's training, which also contributed to the accident.
