Best way to manage 'phase out' products

Example, we have an item with 10 on hand.  We want to sell these 10 but not produce anymore.  We sell about 2 per month so it could be several months before all the remaining inventory is gone.  What i am looking for is a setup that will prevent new planned orders from being created by ASCP so that lower level components aren't purchased.  I also want to get a message (exception message?) that tells me the 10 have all been sold and the item should be terminated.
This seems to be a typical situation in any company.  Ideas on the best way to handle it?