Data Modelling when connecting to SSAS Tabular

This should be considered a critical feature

This is needed not just to mashup data, but to allow users to make minor changes like establish new hierarchies or groupings.

This is a big road block for us. We need to be able to make changes to enable true self service BI.

This feature would make a big impact for users with other tools wanting to change. This would rock the hell out of Power BI

Yep. Mixing internal and external data is important to us.

This is indeed a key missing feature and hard to understand why Excel can connect to multiple sources likes SSAS and other, but PowerBI cannot. It might become a kind of complex problem under the hood, but in my case it would be sufficient to render the different data sources on different Report pages. May be this is easier to accomplish?

It seems like this shouldn't be a problem. You CAN add data from SSAS to a report with SQL Data, but you can't start from a SSAS model and add data from SQL sources. For me, this would be the more sensible approach. I have most of the data I need in my SSAS model, I just have some other bits out there I want to combine sometimes.

I believe this is pretty much the same idea: https://ideas.powerbi.com/forums/265200-power-bi-ideas/suggestions/12532173-ssas-get-data-multiple-data-sources?page=1&per_page=20

STRUGGLE TO UNDERSTAND WHY POWER BI PUT OWN LIMITATIONS TO SSAS tabular.