Your question sounds like you do not have an Accpac programmer or maybe you didn't buy Accpac's source code.
ok....
There is not a rule to notify PO that warehouse got inventory onhand. But you can make two light modifications to improve or fix that.
1) Include a box to display Inventory Onhand. It will
help PO users, as a additional support, to decide if
they have to order.
2) Build a little routine to display a message when there
is inventory on hand.
Additional note: Do you have a Rolling Forecast program?
If not you should think on it. A RF will tell how much you have to order. It guarantees the minimun you want to have at warehouse per item.
"Accpac can does more for us and its source code let us do much more for ourself."