Analysis of accidents through combination of CAST and TRACEr techniques: A case study

Abstract

This article presents a methodology for accident analysis developed from the combination of CAST - Causal Analysis based on System Theory, derived from the STAMP (Systems-Theoretic Accident Model and Process) accident causation model and the human error analysis/investigation tool TRACEr (Technique for the Retrospective and Predictive Analysis of Cognitive Errors). This combination was proposed from the perceived need to structure one of the stages of the application of the CAST technique where unsafe control actions, or human errors, that occurred in the course of accidental events are analyzed, for which the application of the TRACEr technique proved extremely useful. From the application of the proposed combination to an accident that occurred in an oil production unit in operation on the coast of southeastern Brazil, it was possible to obtain a deeper understanding of the psychological phenomena that preceded one of the unsafe control actions, as well as the identification of performance shaping factors that contributed to its occurrence. These results demonstrated the conceptual cohesion and mutual complementarity of the associated techniques, which allowed a comprehensive understanding of the accidental event and, consequently, the elaboration of safety recommendations more appropriate to the findings of the analysis, better specified to the aspects of human factors involved.