If you use a BW/4HANA instance, you have to use the BW Modeling Tools (BWMT) to build your data model. You could only build Advanced DataStore-Objects (ADSO). If you create a new ADSO, you have to select a BW-Project and an InfoArea. After that you have to define a technical name and a description. You could also use a template to build your ADSO.
After I started my BW/4HANA instance on cal.sap.com and everything was working, I logged on and typed RSA1. But there was no modeling tab anymore. Then I rememberd, I need the BW Modeling Tools. So I installed the latest Version of Eclipse and the BW Modeling Tools. After that I need a Project. The project is the binder for all activities in our BW system. Make a right-click in the Eclipse Project Explorer and choose BW Project.
This week the new open SAP course BW/4HANA in a Nutshell started. It is a free course. One big thing is that BW/4HANA no longer supports the good old BEx Suite. You now have to use the BW Modeling Tools based on Eclipse. In this and further posts I will go deeper into the BW Modeling Tools and what is possible and what is not possible at the moment.
If you have any questions feel free to ask or correct me ;) So let's get started.