Why do we get the error message ‘Quantity exceeds the Purchase Order qty ‘ while post order?

Cause:
The System will not allow post order in case of channel partner in which sale order qty is greater than the Purchase Order quantity. The system will show the following message ‘VTPOQTY2’, ‘Quantity Tolerance’, ‘Quantity exceeds the PO qty and the tolerance percentage defined in item master’ on posting the Sales order. Users can refer to the posting log to get the error details.
[ Example can be as below:
Item_code – FG00000294
Order_qty is 450
and available qty in Open orders is 432.]

Solution:-
Users should ensure the stock is sufficient for the item used in Sales order. Secondly, the quantity entered in the Sales order should be equal to Purchase order quantity or the quantity is within the tolerance level of the PO quantity. Users also need to ensure that the item line number is properly added.
Note :
In item master, Receipt Qty Tol% field defines The item tolerance allowed between an actual receipt and a PO quantity.
Users should check if the Receipt Qty Tol% field is defined.