Hi,
I can say it was correct, means here particular PO has 3 pallets is there, each pallet was 100x3 = 300.
user performed 3 pallets particular PO
but this PO delivered with quantity 10+15+20 = 45.
total PO quantity = 300.
delivered quantity = 45.
open quantity = 255.
if have any issue cross check with ME23n transaction in ECC.
Thanks,
Phani.