Is there a software which finds alternate models for owned sets? I know for example the catalog of BrickLink and now I wonder if there is a software which can calculate from the inventory lists which other models one can build with an owned set?

To more detail: If one owns a set with a lots of parts, there have to be some set with less parts that are included in the big set...

I have now browsed Rebrickable website, but there are only self-made instructions for owned sets. This is nice, but I searched for "original" models, which I can build of my owned sets. Did I made something wrong?
You're describing rebrickable:

https://rebrickable.com/

Besides official models, also hundreds of fan created models are available.
It's a terrific resource