Reduce PO item quantity when there is a supplier return

[mark_perkins]

Hi Experts,

We have a scenario where we have a PO item for a quantity of 30.  The supplier sent an ASN for a quantity of 30.  The PO item status shows a quantity of 30 shipped.  However, 8 pieces were bad and we returned them in our SAP ECC system.  We manually rejected the 8 pieces in Ariba PO receipt.

However, when we attempt to reduce the PO item quantity to 22, the system gives an error "Quantity cannot be less than 30 (the number shipped)."

How can we resolve this error and reduce the PO item quantity?

Thanks in advance for your help