How to Design a Universe from SAP R/3 data ?

Hi,

I have data in SAP R/3 system . i need to design a universe based on that R/3 system data. But we can't create a universe using R/3 data. what i need to do ?

What i know is, Either we need to covert R/3 system data to SAP BI system or we need to migrate that to SQL server using any ETL tool. Is it true ? If so which one is better?

Please help me on this issue as soon as possible.

Thanks in advance..