With Arcadia approach, there is an option to transition LA to PA.
In PA we care about detailed physical components (specific implementation). This is done with modeling physical nodes. But when I transition from LA to PA, all the logical components become physical behavior components rather than physical nodes. Then what is actually the usage?
Simple example: modeling a sensor as logical component with 2 ports (say 2 power supply ports), obviously it has a physical node representation. However that sensor from LA will transition into sensor behaviour component. Not only I do not need a behaviour component at PA, but also I need to model from scratch the physical node (with its 2 power supplies) manually.
The transition LA component is considered a behavior one in the PA (kind of echos the “Logical” aspect of it I suppose), then it is indeed up to you to create the actual PA Node at the PA level, giving information on the actual physical/technical nature of your sensor.
Another example: multiple LA components transitioned from the LA layer may be deployed on one single PA Node component at the PA level depending on the technical choices you make.
Also, another remark: remember that automatic transition in Capella are just helpers to initialize things. A transitioned LA component to a behavior PA component will probably need some modification (renaming…), as you always need to askyourself the same question: “I have defined this at the LA layer (=“how the system will work to fulfill the need”), how is it going to be realized at the PA layer (=how the system will be developed and build”)". This is true for all layers transitions in Arcadia. If you’re just using the transitions to keep all elements unchanged from the previous layer, then there is no value in going through all these layers, just do everything at the PA layer. Each model at each layer is a separate model, answering a different question, and relations between layers are not “refinement” but “realization” relationship.
Thanks for the response! I understand your answer, still it leaves me with open questions on this approach.
The main question I have is - what is the role of the transitioned component within the physical layer ? Do you see it is actually being used within the physical diagram (even if modified) or it is simply serves for traceability, and at physical layer I anyway create also new behaviour components that are more detailed.
Going back to the sensor example:
I know at logical layer I have a sensor. That sensor is implemented by HW element and small CPU element. Each of these are beahviour components at physical layer, because they need to carry some functions (e.g. “sense” and “process and output”, respectively).
In this case, the transitioned LA component named previuosly “sensor” sits in my physical layer, but I am not using it - i created new ones. Of course I could use it as a wrapper for the HW and SW elements, which would be very forced and unnatural (also this approach may not be relevant if at physical layer it is deployed across multiple nodes).
When using Capella’s automatic transitioning function (LA to PA) all the software can do is create the physical functional containers, i.e. the behaviour components as analogues of the LA’s logical components. This may be perfectly acceptable for your design. However, as you’ve discovered in most cases this will be unnatural and not an appropriate design choice. And I would suggest using the transitioning function in your case isn’t that helpful. Rather, it would have been more appropriate to create new structures (behaviour and nodes) – which is, in fact, what you did.
These newly created structures can then be justified by linking them back to you logical component “sensor”. Whether you choose put your new behavioural components into a physical node is your choice as the modeller. But if you did you can again link this to your sensor logical component to demonstrate that the node was created in response to something in your logical architecture, in effect creating a many to one mapping.
Perhaps one motivation for going with the unnatural approach I mentioned of using the transitioned logical component in PA as a “wrapper” for other newly created behaviour components in PA, is to ensure I am consistent with interfaces that I created in LA.
Otherwise, I may justify the structure as you say, but I will not know if I was consisted with interfaces that i designed during phase of LA modeling.