Accounts Payable Workflow-Invoices

As people are moving towards more electronic environments it would be nice to have a workflow process for accounts payable. (For example, an invoice is received, entered into the system by the responsible department, it is sent off to approval by the appropriate department, and then put in a work que for Accounts Payable.) The main thing would be having an approval by management or designated department for the expense before checks are issued by Accounts Payable. Integrating this with VizDocs would be great.