HAZOP Worksheet (IEC 61882)

neqsim.process.safety.hazid.HAZOPTemplate implements a study worksheet following IEC 61882 (2016) — the international standard for Hazard and Operability studies.

Guidewords And Parameters

The seven IEC 61882 guidewords are exposed as HAZOPTemplate.GuideWord values:

Guideword Meaning
NO Complete absence of intent
MORE Quantitative increase
LESS Quantitative decrease
AS_WELL_AS Qualitative addition
PART_OF Qualitative reduction
REVERSE Logical opposite
OTHER_THAN Complete substitution

Standard process parameters are exposed as HAZOPTemplate.Parameter values:

Parameter Typical use
FLOW No, more, less, or reverse flow
PRESSURE Overpressure or low-pressure deviations
TEMPERATURE High or low temperature deviations
LEVEL Separator, vessel, or tank level deviations
COMPOSITION Contamination, wrong phase, or wrong mixture
REACTION Reaction rate or completion deviations

Code pattern

import neqsim.process.safety.hazid.HAZOPTemplate;

HAZOPTemplate hz = new HAZOPTemplate("Node 3 - HP separator inlet",
    "Route HP separator inlet flow within design pressure and liquid handling limits");

hz.addDeviation(HAZOPTemplate.GuideWord.MORE, HAZOPTemplate.Parameter.FLOW,
    "Upstream pump runaway",
    "Liquid carry-over to flare KO drum",
    "FT-101 high-flow alarm; BDV on overpressure",
    "Add HIPPS interlock");

hz.addDeviation(HAZOPTemplate.GuideWord.LESS, HAZOPTemplate.Parameter.LEVEL,
    "LV-201 stuck open",
    "Gas blow-by to LP system, possible overpressure",
    "LSL-201 alarm; PSV-301 on LP separator",
    "Verify PSV sizing for gas blow-by");

String report = hz.report();

Use generateGrid(...) when a facilitator wants an empty worksheet grid for a node before filling causes, consequences, safeguards, and recommendations:

HAZOPTemplate grid = new HAZOPTemplate("Node 4 - compressor discharge",
    "Export compressed gas without exceeding downstream design pressure");
grid.generateGrid(HAZOPTemplate.Parameter.FLOW, HAZOPTemplate.Parameter.PRESSURE,
    HAZOPTemplate.Parameter.TEMPERATURE);

Equipment-aware auto-population

HAZOPTemplate.fromProcessSystem(...) records the simple equipment class on each generated node. HazopConsequenceAutoPopulator.populate(...) uses this metadata when selecting flow-deviation consequences:

The fallback is intentional: process topology determines whether loss of flow causes upstream blocked-in overpressure, downstream loss of feed or utility, inventory depletion, thermal excursion, or another consequence. Generated content remains a preparation aid for an IEC 61882 workshop, not an approved HAZOP record.

Templates created with the existing two-argument constructor have no equipment metadata and continue to use the generic guideword/parameter catalogue. The three-argument constructor accepts an equipment type when a manually assembled workflow has trustworthy equipment metadata.

For automated studies connected to STID extraction and NeqSim process simulation, use the MCP runHAZOP runner documented in Automated HAZOP from STID and Simulation.

See also