Since the cause of a person making a mistake may be influenced by a number of factors a more pointed definition would be that human error is when a person makes a mistake on their own and not as a consequence of other factors. But that still does not really explain what human error is.
A more thorough definition is that human error is a concept for explaining malfunctions, accidents or other unintended consequences from operating a device or system where the error occurred due to the uninfluenced actions of the human operator. In other words human error is when a person causes an accident, breaks something or otherwise messes up. It is also commonly called Operator Error .
Human error serves as a counter point to a manufacturing defect, design deficiency, equipment malfunction or environmental hazard that leads to the problem.
Human error can occur due to a physical or mental incapacity to correctly perform the required operation. It may also occur when procedures or direction are not followed correctly or when warning labels and safeguards are ignored.
An old Department of Defense handbook defined human error eloquently as: mistakes that are representative of the sympathies and frailties of man’s nature. Now a day they define human error as: any personnel action that is inconsistent with behavioral patterns considered normal or any action that differs from prescribed procedures.
To really understand what is human error takes a more detailed explanation.