SubSystem2System Transition

Hello all together,
one question for the weekend:
We started to build a model of one part of a greater system - with the “start small” in our mind to learn.
Now the system and other parts around our small system-part are getting into focus and we will start to build a model for the entire system with our first part and all the other parts.
The question is: how can we get our first model (SubSystem) integrated -in a consistent way (interfaces etc.)- into the System-Model?
The other way round it would have been “easy” – we could have used the System2SubSystem-Transition AddOn.
Do you have any suggestions or solutions for this problem?
I think this is a general problem when you have several topic-specific engineering-groups and you want to put all their SubSystem-models together into a model of the entire System.
Kind regards

You are perfectly right, this is a particular case of a much wide picture which is the management of the organization of models.
System to subsystem seems simple. For one given system because at some point you might want to reuse this subsystem in another context
In your system, you might want to assemble building blocks that are defined in other models.
Between models, sometimes you will need to see a component and its function as a component with functions, but in others, you might want to see it as an actor and its functions.
Sometimes you have a very detailed descritpion of a building block in one library, but what your need in your system model is a kind of astracted/simplified version of this building block.
We could think of many other cases. We understand quite well the issues and challenges, but we are only moving forward at a very slow pace because of resources / priorities. Any contribution is welcome (brains, money,
In your case, what I would try to do is
Transform the project in a library (manual process)
Attach the library to the system project
Automatically creates a REC with the whole library content (comes with Capella 1.2.1, see the dedicated “what’s new webinar”)
Instantiate in the system project
Hope this helps

Hello Stephane,
thank you for your answer - I will try it this way.
When will Capella 1.2.1 be published?
Will it possible to “import” two/several “subsystem-libraries” into one system project?
Kind regards

Development versions of Capella 1.2.1 can already be downloaded on the Polarsys servers:
But be careful, these are not official, fully validated versions.
The target for the official version is end of May.
Yes it is possible to have several libraries attached to one model. See at 19’11 on

Hello alltogether,
Transform the project in a library (manual process)
How can this be done? By moving all elements to the library by the “Transfer View”?
When will it be possible to copy/move elements form a library to a Capella Project? Capella-1.2.2 or later?

Hi Richard,
Yes I believe that you can move project elements into a library since Capella 1.2.1 using the transfer view, I think it is documented in the Capella embedded help under the section that talks about libraries (last entry if I recall well).
Then you should be able to transform them into REC and copy them to another project.
Stephane - Obeo

Wait, it’s much easier to transform a project into a library. All you have to do is use a text editor and…

  1. Open the .project file and replace
    org.polarsys.capella.project.nature with org.polarsys.capella.library.nature
    This file is hidden, you can unfilter it from the project explorer via the explorer menu-> customize contents, uncheck “.*resources”
  2. Open the .melodymodeller file, and change the root element from:

< …


Hello Felix,
really??? This would make things very very very much easier!!!
Thank you very much! This was what I was looking for.
When right-click on an open project there is an option in the context-menu:
=> Configure => Convert to Modeling Project
(don’t now what it means or can do…)
What about adding another option? => Convert Capella-Project to Capella-Library

Convert to modelling project is a sirius specific action, has nothing to do with capella.
To change the project nature, you can also right-click on the project and then under “Properties” there is an entry “Project Natures”. Remove the capella nature, and add the capella-library nature. Still, you have to change the type of the root element in your .melodymodeller model.
IMO, what makes up a library, is the content of its model, not the type of its root element… I think capella gets this wrong.

Oh, I just saw that the project natures preference I mentioned in my previous post was only added in eclipse photon,
so you have to use a text editor like I said before.

Not able to get the text editing approach to work on Version 1.3.
Any updates.

Was able to get to work… as posted on another thread there are 2 occurrence that need to be replaced in melodymodel file.