Model the following business process for handling down

payments.

The process for handling down payments starts when a request for

payment has been approved.

It involves entering the down payment request into the system, the

automatic subsequent payment, emission of the direct invoice and the

clearance of the vendor line items. The clearing of the vendor line items

can result in a debit or credit balance. In case of debit balance, the arrears

are processed, otherwise the remaining balance is paid.