Excavation Unit Assigned To ID

The assignedToId of an ExcavationUnit links the unit to the crew member in charge of it, so you can see at a glance who is excavating which test pit or trench and hold a clear chain of responsibility for the records that come out of it. It is optional — a unit can sit unassigned before work begins or between diggers — and it points to a User in your tenant through the "UnitAssignee" relation, which means the same person shows up in their list of assigned units. If that user is later removed, the link is simply cleared rather than deleting the unit, so the excavation record survives staff changes intact.