Hello K.Nongnuch:
I don’t believe it’s necessary to copy open PO into new BU, because our expectations is that at the time of cut-over, all open PO ( and transfers) and would have been received.
Given that your PO usually don’t remain open for more than few days, it would be practical to just input any OPEN ( uncompleted) PO in the new BU, conversion of open PO was out of scope of BU separation project from the beginning, and I don’t think we should spend time/money on converting any PO/transfers.