Can we generate one item in PO that from many SC items

Dear ,experts :

    This question is about the SC and carry outsourcing scenario .

    Under the same location ,the end users create their Shoping carts .They are the same materials .then  the purchaser should serach the SC and carry outsourcing and create PO . But the po must have the same items(just the quantity different ) that from SC .

    under this situatioin , the vendor should  delivery by the PO items ,and the purchaser should do "GR "by the PO items .

       I just have one idea ,we can use the ,PO create BADI .and delete the same items ,and add the quantity to one item.

So ,any body has other suggestions to this problem ?

   Look forword to your suggestons

BR

Alex