What is HAZOP and how is it used in process safety?

HAZOP (Hazard and Operability Study) is a systematic technique for identifying potential hazards and operability problems in process designs. A multidisciplinary team applies guide words (No, More, Less, Part of, Reverse, Other than) to process parameters (flow, pressure, temperature, level) at each node. For each deviation, the team identifies causes, consequences, existing safeguards, and recommendations for additional protection. HAZOP is typically conducted during detailed design phase and is a key input to SIL determination. It documents hazards that may require SIF protection.