Purpose and Timing

A HAZID is a structured, team-based study that systematically identifies hazards associated with a facility, project or operation, using guidewords applied to defined nodes or areas. It is broader and earlier than a HAZOP: it looks at external and occupational hazards as well as process ones, and it works from concepts rather than finalised line diagrams.

When to run one

• Concept and early design — when layout, siting and technology can still be changed cheaply.
• Before a major modification or a change of service.
• Before a new operation — a new campaign, a new location, an unfamiliar activity.
• After a significant incident that suggests the original study missed a class of hazard.

Value depends on timing

A HAZID run after detailed design is largely an exercise in documenting what can no longer be changed. The single biggest determinant of value is whether the findings arrive while the design can still absorb them.