Hi Mandy,
Generally as per the proven practices, the workflow will be out of the box and will have a standard format. Though it can be customized accordingly as per your requirements, if you are on Ariba On-Premise. However in case of On-Demand, there are minimal chances that you can duplicate this from SAP MM. It would be better to check with Ariba Support, if they can customize it to accommodate your requirements.
Thanks,
Sandeep Jain