Seeing the Big Picture of Mishaps

The analysis of major accidents in safety-critical systems requires a “big-picture” approach, with the capacity to accommodate contributing factors from within the organisations involved and from dysfunctional interactions between different parts of the broader system. Rasmussen’s AcciMap approach is useful in this regard, as it illustrates how multiple factors throughout the system combined to produce an accident. This article describes the application of this technique to the Überlingen mid-air collision and draws on this application to discuss the benefits of the AcciMap Approach. These include its capacity to incorporate contributing factors from all system levels and illustrate their interrelationships succinctly; to depict the activities of front-line workers within the context in which they occurred; and to aid safety recommendation development.