The Abnormal Situation Management (R) Consortium(1) funded a study to investigate procedural execution failures during abnormal situations. The study team analyzed 20 publically available and 12 corporate confidential incident reports using the TapRoot (R) methodology to identify root causes associated with procedural execution failures. The main finding from this investigation was the majority of the procedural execution failures (57%) across these 32 incident reports were associated with abnormal situations. Specific recommendations include potential information to capture from plant incident to better understand the sources of procedural execution failures and improve use of procedures in abnormal situations. (C) 2011 Elsevier Ltd. All rights reserved.