A client forecasts a needed item number, then they submit a Purchase Order, a Sales Order is made for the Purchase Order, A Work Order is made for the Sales Order, the item number is manufactured, the Work Order is closed, the item number is delivered to the client, the Sales Order is closed, an invoice is generated, the invoice is paid, the PO gets closed. Unless you're ASML, in which case, there is a d12 roll to decide if its gets closed or if you just leave it there forever.