Production version for different periode

Hello Expert,

I have a requirement like below please suggest some solution

One of my finished material having two alternative BOM say 1 and 2 and I have a requirement in MD61 for 500 pcs in current month and another requirmnet in next month for 1000 pcs

Now the when we run MRP I want system should take alternative bom 1 for current month requirement(500 pcs) and system need to take alternative bom 2 for next month requirement(1000 pcs)

Any body have any idea about this solution with less master data maintenance for user

Thanks in Advance

Abu fathima