Hi Pavan,
We have recently went live with Ariba integration using SAP PI as middleware. We have used ITK to upload master data to Ariba. These master data files are generated in the S4 system using ABAP program in .csv formats. Then PI interface runs and bring those .csv files to PI server, where a zip batch job will collect those files into a zip file. This zip will be placed into the InDir of ITK folder. Our basis team have scheduled Ariba ITK job on PI server NWA which will run and pick that zip file to load master data (wbs elements, company codes, user data, etc) on to Ariba instance.
Let me know incase you need more information on this.
Thanks
Varun Goel