We are trying to figure out how to do a work order to take a purchased parent part which has an incorrect internal component in it, change out the incorrect internal component here in-house and replace it with the correct component out of our stock, and then put the parent part back into inventory as it's original part number but have the additional cost added to it.

We buy the completed assembly from our vendor as a "Purchased Part", we don't build it in-house.  I know I can do a negative purchase order, then change the part from purchased to make from, make a bill of materials, then a positive purchase order, etc.  What we really want to be able to do is make a work order for the purchased part number, then the bill of materials would include that purchased part number plus whatever parts it took to change the wrong internal component(s).  That way it pulls the purchased part from our inventory, pulls the part(s) necessary to fix it, and adds the costs together and then puts it back into inventory as the original part number, at the higher price, when we close the work order at "Enter Finished Production".

klconard,
 
There are systems out there that do what you are asking for as part of the capabilities of the system. DBA is NOT one of them. You need a system that allows you to "purchase direct" to the job and you are also explaining what is basically lean manufacturing as well, using a single job to accomplish a "set" of processes related to a single part number.
 
Notwithstanding the below post from my friend Lynn, since there are "workarounds" for a lot of things. But my comment would be directed at built-in functionality and capability.