For some important functions during the order fulfillment process, classical transactions are still the method of choice. However, SAP has ensured that these classical transactions look very similar to the new SAP Fiori apps by applying a SAP Fiori theme. Therefore existing SAP users can become productive on SAP S/4HANA quickly and waste no time adapting to the new environment. This is why a non-disruptive upgrade to SAP S/4HANA is possible without having to change the way the users carry out their daily business.