Dear,
In SAP we have WIP batch concept, i mean after confirming the first phase create this WIP bath which can be created for Process/Production order and set the SLED for this batch.Explore on this more from the below links.
http://help.sap.com/erp2005_ehp_04/helpdata/en/47/31629eebd20c50e10000000a11466f/frameset.htm
Thanks,
Naresh.