Rating accident models and investigation methodologies

This is a report of research to identify, rate, and rank accident models and accident investigation methodologies. Models and methodologies used in 17 selected government agencies were examined. The examination disclosed 14 accident models and 17 different accident investigation methodologies in those agencies. To determine their relative merit, evaluation criteria and a rating scheme were developed from user data, statutes, applications, and work products, and each model and methodology was rated. The ratings indicated significant differences in their relative merit. The highest rated model and methodology were tested to determine if the estimated ratings were supported by observable differences in actual performance and to compare investigative results against previously reported cases. Differences found prompted further examination of the benefits and problems that would result from implementation of the preferred model and methodology. Additional exploration of comparative performance measurement techniques disclosed further differences affecting the selection decisions. The models, methodologies, criteria, ratings, rankings, test results, and initial measurement findings are summarized in this report. Issues ranging from oversimplification to ethical questions were discovered during this work. The findings strongly suggest that significant accident investigation program changes should be considered in agencies and organizations using lower-ranked accident models or investigation methodologies and that a compelling need exists for more exhaustive research into accident model and accident investigation methodology selection decisions.