Payables Transaction Workflow is a new feature released with Dynamics GP 2015 R2. This is a new object for the GP workflow 2.0. A lot of people are going to like this to help automate their payables process.
“The Payables Transaction Approval workflow type will allow you to submit and approve each transaction in the Payables Transaction Entry window. Approval is also available through the email notification and the navigation lists. The PM Batch Approval workflow type is still available as well.”
This feature along with the existing purchase requisition functionality will encourage a lot of people to set up and start using the workflow functionality in Dynamics GP.