Epilogue:
Subsequent to the original 1980 report, further research disclosed a way to achieve this ideal. The key change was to separate the production of a description of causally related interactions during the accident process from subsequent uses of that description.
This means the investigation output is the description and explanation of what happened.
That requires different data, knowledge and skills than developing problem statements, remedial actions and post-implementation monitoring plans. These findings are described in ģInvestigating Accidents with STEPī by Hendrick and Benner, Marcel Dekker, New York, 1986 and subsequent publications by this author.