Rolling Forecast - Offset for Forecast consumption

Hi Guys,

I wanted to set up / configure a rolling forecast consumption concept. For example :

                                   February      March                                    April

Forecast                       200                 20                                        50

Shipped Qty                  50                  100                                       50

Rolling Forecast                       150(200-50 From FEB)                 70 (170-100)              

New Forecast                                   170(150+20)                              120

And So on.

So as shown above its clear that 200-50 is done and the result of the difference between forecast and shipped Qty is made available in the next Month Period ID as rolling Forecast(150). Then the result of this can be Added to current month forecast to calculate the New forecast for the month. Now the Rolling Forecast for the month of March would be 70 and this should reflect in April as a carry forward.. then the logic continues...

Looking forward to customization and calculation logic ( at all levels) help.

Thanks

Br

Arjun Kumar Rao