SSAS partition creation too slow

Hi,

At times I am getting issue in prod where the partition creation is too slow. Usually it takes less couple of minutes and on some days it takes couple of hours for that.

Can you please suggest some reason for that.??

Some Analysis-  I'm using lazy aggregation in cube. Can that be a reason for the slow partition? If yes can there be a way to handle this?

Thanks

madhur_ms