Transfer Profile settings

Hi Experts,

We are currently Transferring Forecast from SAP APO DP to R/3 ECC.

I have a small doubt in this. We have multiple R/3 servers like production , development, quality , etc. But when ever i tranfer forecast from APO Production it goes to R/3 Production server. I have seen that we don't give Target system in our transfer profile. How does SAP Understand to which system it should transfer the values ? Is it due to Integration model ???

Thanks.

Emani