2 delivery schedules from 1 vendor

Hi, we want to
implement our procurement in a way, that we buy with a special delivery
schedule 1 only to a fix quantity.Afterwards we want to buy the same thing with
a second delivery schedule 2 from the same vendor. The release orders should show
always the correct status (schedules lines from delivey schedule 1 until to a fix quantity

and then from the other delivery schedule 2). So we want to see direct in
the release orders only the schedules until the fix quanitity from the delivery
schedule 1 and afterwards directly and automatically the schedules from the
delivery schedule 2. So we have a fluent switchover from one to another delivery
schedule.

Is this possible without SCM and APO ? Maybe over a BADI or User-Exits ?

Thanks

Wolfgang