Aggregation after Collapsing InfoCube

Hi All:

As after collapsing an Infocube, records with same business key are aggregated, then after two DTP runs we can have a record Sales =USD 100 twice. This means that after collapsing we will have one record with USD 200 which might be wrong (duplicate sale revenue) if the DTP runs with full update. Any ideas on this, or business scenarios that might justify it?

Thanks