Maximum & minimum lot size

Hello,

I am using maximum and minimum lot size in APO materials master.

The maximum lot size is 10,000 and minimum lot size is 2000 for the same material.

But when , I am running the heuiristic, the lot size considered by the Heuristic run is different than what is defined in the material master. While running the heuristic system is showing lot size as 1 and 9999999.

Plesae let me know , where to change or what is causing the lot size to appear as 1 to 9999999.

Regards,

Ravi