About a year ago I was assigned to an SAP data migration project at a global engineering firm. The objective of the project was to migrate the master and transactional data from the legacy local SAP ECC system to a global SAP system. The project involved the extraction of data from the company's legacy systems into a staging area (a SQL database), where several mapping rules and transformations were applied to meet the requirements of the new system. The data was ultimately populated into excel templates designed by the functional team which were then uploaded via LSMW into the new global SAP system. The ETL process took place over several mock runs and were loaded into several test clients before the final load into the production system.
With regard to the above-mentioned process of migrating the data (Extract from Legacy -> Transform in Staging -> Load into global system), I would like to understand if this data migration project could have been approached differently, or have been migrated using any relevant SAP services? Could there have been a more efficient and robust process to complete the data migration?
Your advice would be appreciated.