Available to Promise

On a Sales Order Line there is a field displaying the On Hand position and one showing the Available position. However we have orders going forward up to a year so the available can show a negative position even though the On Hand quantity is considerable.

Sales want to be able to see what the demand is for a defined period - say one month - without having to keep going to the Available to Promise tracker.

Any suggestions as to how best to do this?

Thanks

Adrian