From hazard review at Imperial Chemical Industries from 1963, published by H. G. Lawley (Operability Studies and Hazard Analysis, 1974) and first printed as HAZOP by Trevor Kletz (Hazop and Hazan, 1983).
Walks a process design node by node, applying guide words such as no, more, less, and reverse to each parameter to find deviations, their causes, and their consequences.
When to reach for it
When designing or reviewing a plant or process where a deviation in flow, pressure, temperature, or timing could cause harm.
How it runs
- Assemble a team with design, operations, and safety expertise.
- Divide the process diagram into nodes.
- List each node's parameters, such as flow and pressure.
- Apply each guide word to each parameter.
- Record causes, consequences, safeguards, and actions on a worksheet.
Where it sits in SOLVE eX
Go to the source
- Operability Studies and Hazard Analysis, Chemical Engineering Progress, 1974
- Hazop and Hazan: Notes on the Identification and Assessment of Hazards, Institution of Chemical Engineers; fourth edition 1999, 1983