The only time you should delete a resource is when they were entered by mistake. Schedule XP links patient appointments to the resource and time slot they were scheduled on. Deleting a resource will effectively delete all appointments seen by that resource in the past. When you archive a resource instead of deleting them it allows the computer to maintain data integrity while not allowing any more appointments to be scheduled with them. The resource will not show on the schedule options but will still show on the Schedules form. You can always un-archive a resource if they come back.