You are guessing incorrectly again.
OK, this is becoming annoying.. I asked an ATA22 Airbus engineer, this is what he told me:
for both SA and LR:
THAV makes the hardware.
AIRBUS makes the FG(E) software
THAV and
HWL make the FMS software
THAV integrates everything in the box (even for
HWL software) for every serial aircraft.
I don't know what your problem with my post was, but what he wrote to me, is just what I said in the last post.
Sorry for everybody else, still reading, for the confusion...