Overwrite data in the Planning Cube

Hi Gurus,

I am new to BPS, I have created a simple Manual planning layout for my users

where they could enter their plan data for either plan or forecast version.

As you all know the cube is always additive and cannot overwrite the Keyfigures directly

I want to know if there is any in built planning function which would do that.

For example Right now if the users first enter like

Plant Profit center version QTY

1000 2200 SP0 100

and they think the number 100 is too much and they want to readjust it 80

they want to enter as 1000 2200 SP0 80 but cube is additive so it is making the QTY as 180 instead of 80.

As of now they are entering as 1000 2200 SP0 -20 to adjust it to 80 which they don't want to do

Hope I communicated well.

Thanks

Jay.