This is difficult to handle this in Sage X3. The disassembly seems appropriate but you will have no update of the traceability and - I think - you cannot enter a serial number in stock twice (because it's unique: only exception is a customer return but in this case the component is not returned from a customer, the Finished Good SN is returned).

So a possible work around to manage traceability is to create a new work order where the finished good is consuming itself and the new SN and at the end you will produce the Finished Good and the old SN (managed as co-product).

Again, in this situation, you may be blocked because the system will forbid you to receive the old SN (to verify). Then the 2nd work around is in that case to delete the related record on STOSER.

Then I can suggest this process:

1. Perform the customer return on the finished good
2. Create a Work order on the same finished good with component E as co-product (so it must be set as manufactured and a dedicated BoM alternate must exists). Modify the components list to ensure the finished good and product E are the only valid components.
3. Delete the old SN record (SN20015) for product E by using a data base mass update (AMIEXE - new transaction to setup).

1. Issue the stock linked to the FG and old SN
2. Receipt the stock linked to the FG and new SN
3. Track time to capture the cost of the swap
4. Close and cost the work order

This process has not been tested and it involves uncontrolled deletion in the database. So I advise you to test seriously before using on your Live folder. You can simplify this process with some specific development.

Or maybe, a much simplier process is to create a direct customer return based on the component E for SN20015 and deliver the SN20017 instead. In that case, the traceability will not linked the new SN20017 to the finished good and the cost linked to the swap is not captured.