The analysis of accidents is an analysis in hindsight, since it is made after the accident has happened. The accident analysis can indicate several direct and indirect causes; but to a large extent, it is the fact that the causes occur simultaneously that makes the accident happen, rather than the presence of one single cause (Rasmussen, 1997, Jørgensen, 2002). Precisely due to the fact that a single cause does not necessarily lead to an accident, but only when other causes occur at the same time, makes it difficult to point to the actual “culprit”. This makes it hard to perceive causes, which in one situation mean nothing, but in another are crucial for an accident to happen.
Perhaps this is the reason why actions and choices come under scrutiny when an accident has to be explained and the “cause” located. There has been much focus on human errors and mistakes, where differentiations are made between conscious and unconscious mistakes, as well as between errors in workmanship, errors in memory, wrong choice of method, misunderstandings, and lack of knowledge (Rasmussen, 1987; Reason, 1977). This perception of the different ways in which humans make mistakes and act erroneously has been seen in a framework of explanations and conditions for why people make mistakes due to the situation and context (Reason 1997). Organization, decisions, and working conditions contribute to affecting what risks are present, but also whether the necessary barriers are present to prevent risks that lead to accidents (Reason 1997).