The risk missing from the diagram

A hazard overlooked early becomes expensive to address later.
HAZID helps explore hazards and interfaces while design decisions can still change. For new storage, consider neighbouring units, emergency access, shared utilities and external events alongside the substance itself. Operations, maintenance and project specialists bring different knowledge. A useful output connects credible scenarios to decisions, responsibilities and traceable assumptions.
Record what remains unknown so that a provisional assumption does not silently become a design certainty.
Which interface joins your projects too late?

The discussion improves when interfaces are represented by those who manage them: operations, maintenance, logistics and design may see different boundaries. Recording the limits of the review distinguishes what has been explored from what needs subsequent analysis and additional expertise.

The decisive issue is the connection between scenario and decision. Incomplete data or an overlooked interface can change interpretation even when the document looks orderly. Recording what remains to be verified keeps technical questions visible and assigns them to the necessary expertise and subsequent review. Numerical presentation does not remove uncertainty about the underlying conditions.