Hello Jana,
just wanted to add that from November 2015 there are two flavors of SAP S/4HANA, on-premise edition available:
1. SAP Simple Finance, on-premise edition 1503
2. SAP S/4HANA, on-premise edition 1511 (see blog post from Sven SAP S/4HANA - Frequently Asked Questions - Part 8 - 1511 update or my new post http://scn.sap.com/docs/DOC-68976).
SAP Simple Finance, on-premise edition 1503 is the one with the application simplification in FIN area (based on EHP7). SAP S/4HANA, on-premise edition 1511 is the one which includes application simplification in FIN and LOG. Here you go to 1511 from any EHP to S/4.
Kind Regards,
Frank