Re-configuration vs Update due to Item new item codes

Hello colleagues

My client has a requirement to define new item codes to replace the existing ones with on-hand quantities. We are on R12.1.3 and upgrading to R12.2.10. My question is how best can we do the following;

• Migrate on hand quantities to the new item code
• Can we perform this exercise without re-implementation considering the method of data migration, as well as considering open purchase orders to be received, open sales orders to be fulfilled, open payable invoices, approved supplier lists, sourcing rules and assignments just to mention a few.

Thank you

Talimba