What's Wrong With HAZOPs? HAZOPs are not as effective as they could be for several reasons: The focus on small nodes obscures the big picture. HAZOPs are supposed to identify operability issues, but there is no explicit consideration of operability in a typical HAZOP and no effective way to identify operability issues. The guidewords for a typical HAZOP are Flow, Pressure, Temperature, and Level. But flow deviations cause most pressure, temperature and level deviations. Discussing all four of the guidewords duplicates effort and causes tedium. HAZOP reports are difficult to read and therefore are not used for much after the HAZOP. HAZOPs are Not Fun! Most people don't enjoy HAZOPs and since they often run for days or weeks at a time, the resulting tedium impacts the effectiveness of the process. Risk assessment in HAZOPs is often difficult, ambiguous and not repeatable. Stream-based HAZOPs address all of these problems.