Abstract: The present study began with an assessment of the reliability and usefulness of an existing minor event coding system in a British `highconsequence' industry. It was discovered that despite the fact that the system produced replicable data, when tested in a reliability trial the causal inferences it was producing failed to meet the normal criteria for statistical reliability. It was therefore felt necessary to create a new model of the human factors component of action in this industry, from which a model of human factors error in the same industry could be inferred. A set of codes (to facilitate statistical analysis) were deduced from this last, which were then tested in a new reliability trial. The results from this trial were very encouraging, and after a six-month pilot study in which it demonstrated its usefulness as a trend and patterning tool, the system is now being phased in within this industry.
B. Wallace, A. Ross, J. B. Davies, L. Wright, M. W