Hi Payal,
For serialized refurbhishment process.
1. Serial Number profile should have PPAU serializing procedure with usage 2 or 4
2. Material should have the serial number profile assigned
3. Create a refurbhishment order, on save or click objects in the header screen to enter the serial number
4. Do a Goods Issue, here also you need to enter the serial number
5. Do Goods Receipt, on entering into the transaction, system will display the serial number below.
Regards
Terence