An AcciMap is a multi-layered causal diagram that arranges the various causes of an accident in terms of their causal remoteness from the accident (Rasmussen, 1997). This approach differs from other accident analysis techniques by identifying causal factors from all parts of the system in which the accident took place, ranging from the physical sequence of events and activities of the individuals involved, right up to the causes at the governmental, regulatory and societal levels. Unlike other methods for accident analysis, this approach also assembles the contributing factors into a coherent causal diagram that illustrates the interrelationships between them, thereby highlighting the problem areas that should be addressed to prevent similar accidents from occurring in the future.
The method involves asking why an accident happened, in order to identify the factors that caused (or failed to prevent) its occurrence. This process of asking why is repeated for each of the causal factors uncovered, so that an understanding is gained of the broad situational context within which the sequence of events took place. The causal factors are then assembled into a diagram that reveals how conditions and events from throughout the system interacted with one another to produce the final negative outcome. This process is useful for highlighting the organisational and systemic inadequacies that contributed to the accident, so that attention is not directed solely towards the events and human errors that led directly to the accident.
This technique was used in the analyses of the F-111 Deseal/Reseal Board of Inquiry (Royal Australian Air Force, 2001) and several Australian Defence aircraft accidents and incidents. It has also been used to analyse accidents that have occurred outside the aviation industry, such as the Esso Longford gas plant explosion in 1998 (Hopkins, 2000) and the contamination of Canadian drinking water in 2000 and 2001 (Woo & Vicente, 2003).
- Rasmussen, J. (1997). Risk management in a dynamic society: A modelling problem. Safety Science, 27(2/3), 183-213.
(This article provides a good introduction to AcciMaps)
- Branford, K., Naikar, N., & Hopkins, A. (2009). Guidelines for AcciMap analysis. In A. Hopkins (Ed.), Learning from high reliability organisations (pp. 193-212). Sydney, Australia: CCH Australia.
(This text provides an overview of the approach and step-by-step guidelines for performing an AcciMap Analysis)
- Hopkins, A. (2000). Lessons from Longford. The Esso Gas Plant explosion. Sydney: CCH.
(This text details an application of AcciMap Analysis to the Esso Longford Gas Plant Explosion)
- Woo, D., & Vicente, K. J. (2003). Sociotechnical systems, risk management, and public health: Comparing the North Battleford and Walkerton outbreaks. Reliability, Engineering and System Safety, 80, 253-269.
(This text details applications of the AcciMap Approach to two Canadian public health disasters involving the contamination of drinking water)