@viret56 - It should be consistent with the standard (I might venture to say essential) reports you see in QuickBooks directly for open transactions.
For Invoices, Charges, Received Payment and Credit Memo, we're pulling the data from the "Open Invoices" report in QuickBooks.
So for Invoices, it's any invoice that isn't paid. For Received Payments, it's payments that haven't been allocated to an invoice, statement charge or other transaction (balance remaining is not 0). For Credit Memo it's everything that hasn't been applied to an invoice or charge yet.
For Sales Orders we're pulling the "Open Sales Order By Customer" report from QuickBooks. This is anything that IsManuallyClosed=False and IsFullyInvoiced=False.
For Purchase Orders we're pulling the "Open POs" report from QuickBooks. Here's it's any PO that doesn't have all it's items fully received.
Paul