BSG and Product

Hi,

I have the same product PROD that's coming in from two different systems X and Y. Now if we have a user exit that attaches the system name at the end of the product so that we can identify the product source. So when coming from systemX, the product becomes PRODX and when coming form systemY, we get the product name as PRODY. I now have the products sources identifiable. But I have another problem that the system is considering these two as to different products and giving to separate forecasts and planned orders when I want only one. using BSG is becoming problem for me. Can somebody suggest me a solution for this problem?

Thank you.