Logistics invoice verification with difference both in quantity and price

Good morning.

I need your help in order to understand how PO receipts and Invoice postings are made when i have difference in both the quantity and price between PO receipt and Invoice. SAP, in its document "Logistics Invoice Verification (MM-IV-LIV)", describes in pages 119 to 121 how these postings are made page119.jpg, page120.jpg, page121.jpg.

I do understand these examples. However, i run an example where i have difference in the price between the PO and the Invoice, i receive 5 items up front, post the invoice for 10 items and then i receive the remaining 5 items from the PO. I have no price difference between the material master (S-valuated material at 100 euros) and the PO, and finally, i receive all 10 items of the PO, so, i do not have quantity variance either. However, systems performs the same calculation as above. I also observe that i have difference in the the purchase order history postings (1005 in receipts against 1010 in Invoice).

I would be extremely grateful if someone could explain me why is this happening...I would expect that since the quantity is finally the same and i do not have price difference between PO and GR, that GR/IR postings in the second receipt would be 505 euros also so as to match the invoice price...po1.jpg, gr-initial-5.jpg, invoice1.jpg, gr-remaining-5.jpg

Best regards,

Nikos