The Airbus.com site now states: ' The additions are a third Station 50 (where the forward, centre and aft fuselage sections are joined, along with nose landing gear installation); a fourth Station 40 (for wing-fuselage junction and tailplane installation); and a fourth Station 30 (for ground testing and cabin furnishing activities).'
Where an engineering processing system would normally be designed to match input to output, does the chosen imbalance between the number of Station 50s (3) and the outflow Stations 40s (4) and 30s (4) match entirely the difference in in situ construction times between them? The equal nos. of 40s and 3-s suggests their process times are similar. 50 must always operate to feed the line but can anyone pinpoint where future holdups might happen or when a ramp-up to a certain level will require more Stations? I suppose that the outside Stations are there to take frames that might be a little behind to avoid blockages (?)
That would be consistent with stations being reserved to build -1000 test frames.
If the extra (3rd) Station 50 was created at the same time as the extra S40 and S30s then there would a be a bit of a lag before the 3 S50s can produce enough frames to fill 4 S40s and then another lag until 4 S30s could be filled.