The way our business model is set up the vendor often offers product to us and we decide what to buy. We pay for this product based on the condition it arrives to us. The way Odoo's request for quotation and purchase order workflow is set up doesn't seem to support this. In our old system the vendors would send us an offer, we would accept it and create a purchase order, and then when we received it and QC's it, we would deduct any fees for damages, edit the PO to suit, and then follow though completing the order.  In Odoo, once a PO is made, it can't be edited. How can I get around this issue and still use Odoo as an ERP?