My company is frequently receiving invoices with multiple alternate due dates from our providers. Example terms: 5% discount if invoice is paid upon delivery, 2% discount on payments done within a week of reception, final due date within 30 days of reception. (Late payments would also usually trigger penalties.)

How can I handle such purchase invoices in OpenERP?

How can I:

1: register these alternate terms upon creating the purchase order (or upon reception of goods)

2: get management to see the alternate deadlines and potential saving by paying early

3: have the discount applied to payment and average cost calculation when early payment is made