It is unfortunate that the phrase “human error” has become virtually meaningless through over-use and that it is usually interpreted to mean that the person at the “sharp end” was at fault by committing some form of error or violation. It is easy to be misled and to believe that human errors arise because of carelessness, inattention, incompetence, or reckless rule-breaking by the workforce. However, the guidance in this publication should show that human errors occur because the systems for preventing them failed in some way. An incident, then, is not a personal failure but a system failure and to prevent further incidents, it is important to understand those systems: