Purchase Orders Changing, Canceling & Blocking

How the SAP system responds to changes to the PO

Note the following points:
●   Has the PO already been sent to the vendor?
If we change a PO after it has been sent to the vendor, a change document is generated and sent to the vendor. This tells the vendor what we have changed.

●   Has the vendor delivered - in full or in part - the materials covered by the PO item(s) we wish to change?
If the goods have already been delivered, then the changes we can make to the PO are limited. For example, we cannot change the quantity to one that is less than the quantity delivered.

●   Has the invoice already been received or have the goods already been paid for?
If the invoice has been received or the goods have been paid for, and we are intended change affects the price, the change will be ineffective.

We can display the PO history for an item to determine whether deliveries have been received or the item has been invoiced.
Changing a PO:
Add items: To add a new item (if the screen page is full), choose Edit  Enter Lines.

Change items: If the desired changes are not possible on the item overview screen, select the relevant item and choose Item > Details.

Delete items: Select the item to be deleted and then choose Edit > Delete.

Cancelling a PO:
The purchase order is created in the SAP System. In order that the information from the PO can be transmitted to the vendor, the system generates a message for the PO.

Blocking a PO:
We block a purchase order item to prevent a goods receipt involving the relevant material.
We can also block those items for which goods or an invoice have/has already been received.