SAP Maintenance for SAP S/4HANA instance SAP offers customers choice regarding the how and when they want to upgrade to SAP S/4HANA 2023 First, check your SAP production version through system status in SAP After that, check the milestone how and when the Mainstream Maintenance would go for each S4HANA on Premise version as follows. For example, SAP S/4HANA 1809, once the extended maintenance is..