On the completeness of scenario identification in process hazard analysis (PHA)

The ability to achieve the identification of a complete set of hazard scenarios is limited by a number of factors. They include technical constraints posed by PHA methods and practices, human behaviors during PHA study sessions, and poor quality assurance and control in conducting studies. The latter arises from both external factors that adversely impact PHA team performance and internal factors that detract from the effectiveness of studies. This article identifies and discusses these factors and makes recommendations on how they can best be managed.