Data in Planning book vs cube

Hi Experts,

We have a cube for sales data , the data will upload to planning area through BW, this job is running dialy.

For one product in April month open sales order in the Cube is zero but in the planning book  its showing 1 for the same.

Any clue, why data in the cube and planning book is diffeent.

Thanks & Regards,

Srihari.M