Our unit is finding it quite problematic as well. Trying to keep almost 30 controllers current in the 3 "main disciplines" whilst keeping the training system running at full steam is certainly a challenge. Thank heavens for lunch time sessions. Here are just a few areas that cause demands on the system:
Guard Commander
OOA Dets
Sickness
Training
Leave is not too bad now as everyone is reluctant to take 3 weeks off!!
Shiney new aircraft with no engines !!!!!!
I fully agree that we need to have some form of currency. I believe that 28 days (aircrew currency ??)would be more realistic to achieve and maintain while still keeping us able to handle the traffic levels we now encounter.
I've heard a rumour that the 21 days came from "best guess" in order that the ab initios who are replacing the shrinking pool of experience (not that LJAO are too bad off ) have a fighting chance of not finding themselve in an awkward position.