Hazard and operability (HAZOP) methodology is a Process Hazard Analysis (PHA) technique
used worldwide for studying not only the hazards of a system, but also its operability
problems, by exploring the effects of any deviations from design conditions. Our paper
is the first HAZOP review intended to gather HAZOP-related literature from books,
guidelines, standards, major journals, and conference proceedings, with the purpose
of classifying the research conducted over the years and define the HAZOP state-of-the-art.