When a new person comes on board and takes over an existing hat if that person is not fully trained in the area and able to service the staff and customers fully, than it needs to be made known to all the staff that will be carrying out those functions.
If the person who was wearing the hat is still in the company than he will still help out with those functions until the person is fully trained. So a memo needs to be sent to all staff letting them know who is doing what.
In the case that the individual is no longer with the company, then the senior in the area as well as the person over Routing and Personnel (Dept. 1) will see that the duties are being performed. They will let all the staff know who will be carrying out those duties, as well as having the org board changed to reflect this. The org board should be the stable data to go by.