On hand quantity still showing even after job completion

I have created a job of 1 quantity of parent assembly with on hand qty of child item as 3. When we see On hand quantity on material workbench with detailed tab for child component after job completion, we see  3 quantity in Stores Subinventory & -1 quantity in Supply subinventory, but it sould have shown as quantity as 2 in Stores Subinventory. Do help.