A TAXONOMY OF ERROR TYPES FOR FAILURE ANALYSIS AND RISK ASSESSMENT

We describe a taxonomy of error types that builds on work by Reason (1 990) and Hollnagel (1993). The taxonomy uses a faceted schema subdivid ed into layers. Each layer targets a particular analysis task, and a m ethod is proposed leading the assessor through sets of error types at different levels (e.g., cognitive, social, organizational). This allow s the causes of failure to be attributed to one or more error types. T he method is illustrated with two case studies of diverse failures. Th e utility of taxonomy analysis in understanding the reasons for failur e and risk assessment is discussed.