We have requirement to integrate Ariba with S/4 HANA without a middle ware. Ariba should consume the web services exposed by HANA and Ariba should trigger the services. For example if a PR is created in Ariba which should trigger the services consuming the web service exposed by HANA and create a PO in HANA.
Is this scenario possible? What are the possible options to integrate Ariba Solution (not Ariba Network) with SAP S/4 HANA for transactional/ master data without utilizing a middle ware?