hazardandoperability

Hazard and operability study, commonly abbreviated as HAZOP, is a structured and systematic technique used to examine industrial processes in order to identify potential hazards and operability problems. It aims to improve safety, reliability, and efficiency by uncovering design or operational weaknesses before incidents occur.

HAZOP originated in the chemical process industry in the United Kingdom during the 1960s and has since become a widely adopted method across chemical, oil and gas, pharmaceutical, power, and other process industries. It is typically applied to new facilities, major modifications, or changes in operating procedures, and is often integrated into broader process safety management programs.

The method relies on a multidisciplinary team that reviews a process through a series of nodes, usually defined sections of piping, equipment, or control schemes. For each node, the design intent and operating parameters are specified, and team members brainstorm deviations using guide words such as more, less, no, part of, reversed, or other, as well as the context. For each deviation, causes, potential consequences, existing safeguards, and required corrective actions are identified. The process is documented in HAZOP worksheets, and outputs are formal action items, recommendations, and updates to design or procedures.

While powerful for qualitative hazard identification, HAZOP is not a quantitative risk assessment by itself. Its effectiveness depends on scope, the quality of process information, and team expertise. It is commonly complemented by quantitative techniques such as Layer of Protection Analysis (LOPA) to evaluate risk in a more numeric framework.