by It represents an innovative improvement over using the previous versions of SAP R/3 with SAP ERP because of the optimization of SAP S/4 for use with SAP HANA.
The best practices for migration are to copy the current SAP ERP system to a temporary SAP S/4HANA version operating on the cloud and then run the two systems in parallel.
Using the S/4HANA Cloud is a SaaS service that is automatically updated to the newest versions of all software releases.
Migration is best accomplished by running parallel systems with a copy of the existing data ported to the S/4HANA Cloud service.