Essential factors model

The Essential Factors model is an incident investigation model based on determining the essential and contributory factors that lead to an incident. An incident is viewed in terms of an interaction of essential and contributing factors that results in damage to people, property or production. An essential factor is one which when removed from, or added to, an incident sequence will interrupt that sequence. A contributing factor is one which increases the likelihood that the sequence of factors will continue but is not essential to the damage.