ATP-Component onhand pegging to future forecast not made available for Sales Orders being booked

Hi,

We are using ATP based on Planning output with ATP check being performed till components also. The issue
we are facing is below.  We are in Unconstrained Plan.

Finished good item 0510003 does not have any sales orders right now and has a forecast of 50 per week starting from
30-Mar till November. There is no onhand available for the FG.

We do an ATP inquiry with Request date = 07-Apr-2015, Quantity = 450

Result: Scheduled Ship Date =27-APR-2015

249 Units can be Made at the Org
by 07-Apr-2015. Remaining 131 units can be made only by 12-May-2015

Constraint is component 0412876 for which 245
units are available. Rest 20 units will have to be procured from supplier which