Resources

A resource is something a port commits to a job: a tug, a crane, a mooring gang, a piece of equipment. Resources can belong to a specific port or to the account as a whole, which suits equipment that moves between sites.

Assignments

A resource can be assigned to a port call or to a service job for a window of time. Because a tug can only be in one place at once, Censerva checks a new assignment against the ones already recorded and tells you when two overlap.

An overlap is reported, not refused. A port may genuinely decide to double-commit a resource, and refusing would leave an operator unable to record what is actually happening — but it must never happen silently. Two assignments that merely touch, one ending as the next begins, are not treated as a clash.

An assignment with no end time is treated as running until somebody closes it off. That is the honest reading: until the tug is released, it is still committed.

Certifications

A resource can carry certifications with expiry dates, and a certificate can be linked to a document held in the account. A certification that has lapsed is distinguished from one that was never issued — "expired" and "absent" call for different actions, and collapsing them would hide which of the two you are looking at.