Hi Jayshree,
We had cases where Customers load to S&OP from BW or ECC.
S&OP provides pre-delivered data integration content to get Sales History data from ECC. So for faster implementation, you might want to look at the out of the box content there.
Customers with very large data volumes (in millions and billions) may prefer to extract from BW.
Note that the data needs to be aggregated to the time periods used in S&OP eg weekly or monthly before loading to S&OP and the delivered content takes care of this.
Hope this helps.
Best regards,
Raghav