How do GRNs affect PO status?

When you save a GRN with quantities less than ordered, the PO flips to partial. When the sum of GRN quantities per line is greater than or equal to the ordered quantity for every line, the PO flips to received.

The PO stays open through both states — you can keep adding GRNs against it for tranche deliveries. closed is separate: it only happens when you explicitly close the PO, or when matched bills cover all the receipts and the PO is settled.

So the progression is: sent → partial (some lines short) → received (all lines in) → closed (paid and done).

See: finance-grns-receive