HAZOP (Hazard and Operability Study) and Process Hazard Analysis (PHA) are structured techniques used to systematically identify hazards and operability issues in processes, systems, or facilities. By exploring how deviations from intended parameters can arise — using guidewords like more, less, none, reverse — teams can uncover credible causes, evaluate safeguards, and define risk-reduction actions. Originally developed for chemical processes, HAZOP is now widely used across industries, supporting compliance with standards.