When you remove a queue, you must move any existing available work items of that queue to another queue. A queue cannot be deleted if there are any active available work items for that queue.
When you remove a queue, the creation of new work items may fail if the deleted queue names were not replaced properly in the process templates. Before deleting a queue, it is required that process templates are modified to replace the queue to be deleted with the new queue name and also move the active available work items of a queue to another queue. However, if the objective is to remove a queue, then it can be done only when there is no reference to this queue in any of the available work items.
Note: BP Server should be active when you remove a queue.
