This presentation focus on advances on Model Based System Engineering that fUML  brings. fUML, better known has Executable UML, provide a formalization of a subset of UML. UML, and with some extensions and adaptations SysML, can now be analysed in a formal way. That was main grief made by researchers.
First part of the presentation illustrates what is now possible by picking ideas from existing tools, notably Alloy  and OWL . Following this path will enlighten what still must be done from researchers. It also points out how UML/SysML editors and tools can be enhanced. Indeed in current tools you can modelize activities that are not executable, you can describe Class/Block that cannot be instantiated, and so on.
The second part is about current implementation of previous ideas. It starts with a panorama of tools that can be combined, reused or adapted for the new desired features. For instance, it is possible to generate random instances of a model. Doing so helps to be confident in the model constraints. Moreover details will be given on how Topcased ease or not the integration of such a tool in its suite. For instance, it will be shown how Acceleo and ATL are used, but further details will also be given on how it integrates deeply with Topcased Editors for warnings, quick-fixes and so on.