Production Plan Qty Issue

I have qty in hand un check ignore available stock but still required qty is not calculating correctly for e.g my plan qty is this item is CARTONS-29X39.5X32-CM-5 PLY is
qty as per bom : 2500
plan to requested : 2480 (qty as per bom - projected qty)
qty in stock : 170 not effecting and material request created of qty 2480 why ?