Fixed price Purchase Orders scenario in Professional services

We are trying to set up a fixed fee PO for a supplier. This PO should be fixed at USD(ex: $10000). Hours will not be required in S4 and the contractors performing this work will not be entering timesheets. The intent was to set up a PO for the fixed cost of $10K. We will create the goods receipt by using the app “Post Goods Receipt for Purchasing Document” when this work is completed. Accounts Payable will be able to select the GRIR entry when entering the supplier invoice.

When setting up a fixed fee PO, it’s my understanding that we should be using the material code copied from P001 for “Project Based Service Fixed Price”. with material group P004 and GenItemCatGroup: PSFP

But when creating the PO, the PO is looking for Service Performer.

We occasionally have fixed contracts with our suppliers, so we will have the need to create fixed POs moving forward.

What is the best way to address this scenario in S4HANA Cloud professional services?

Thanks,

Vijay