Got it @Enrico Parisi 
So is it a correct way to use ..%RequestHeader.TimeCreated in BO...I mean will it give the exact time?

I need this in the OnProcessInput Method.

Thanks @Enrico Parisi for the help.

It is working as expected.

Will it capture the current sender if there are multiple senders sending request at the same time?

Yes, @Esther Sanchez 

I want to know the sender within my Business Operation method.