Search

Recent analyses of major incidents, such as BP's Texas City disaster and the loss of the space shuttle Columbia, have moved from considering immediate factors and basic organisational failings to considering cultural issues. Cultural issues are, however, even more difficult to incorporate into incident investigations and analyses than are organisational factors. This paper provides a structured approach to analysing individual, organisational and cultural/regulatory factors based upon the Bow Tie methodology, using well-defined rules to distinguish three levels of causation. Level 1 analysis describes barriers implemented at the individual and immediate hardware level; Level 2 describes the organisational factors that support level one barriers; Level 3 describes the cultural and regulatory environment that ensures that the organisation implements level 2, thereby ensuring the integrity of level 1 barriers. Incident investigation and analysis can be performed as a structured search for failed barriers at any or all of these three levels. Both organisational failure (L2) and problems with the safety culture and regulatory environment (L3) can be reliably identified, rather than relying upon the intuitions of investigators.