Hi Thomas,
Some answers:
We could speak in French, but it is beneficial to more people in the community if we stick to English.
Also, please note that I have some time limits on the time I can spend on helping people on the forum, you may want to seek for professional help on Arcadia/Capella is this is something you feel is needed in your case. I read that you don’t have this possibility. But it is always a good idea to benefit from someone expertise at the beginning of a large project rather than realizing too late that you would have done things differently if you knew.
- Working only on activities is related to doing functional analysis work. When doing so, you’re not thinking about who is going to do what, just what’s need to be done. Sometimes if you’re just going straight to the OAB, you may limit you’re thinking to what you already know and may not be thinking outside the box (which is what architects are asked to do). But having said that, going straight to the OAB is completely ok. I do it often. Especially with lower complexity/known domains
- Yes you can certainly hide information from some OABs if they are not useful. You may also have an OAB that has got everything on it (for you to work on) and smaller OABs for presentation purposes. Having the same activities in different OABs is completely normal. You don’t want to duplicate activities. OABs (and diagrams) are just views on your actual underlying model.
- One OAIB per capability and one OAB per capability is completely ok, it is for you to decide how it is going to be the best to organize your model and diagrams depending on your context and objectives. And also, if you have one OAID and one OAB per capability, that does not mean that you do not have other OAIB and OABs if they provide value to you.
- It is possible to create a circular one, but not from the start. Reason is because: even if it is circular, Capella needs to know which one to start with, and it is not making this choice for you. More info on how to do it here: Creation of functional chain - #8 by StephaneLacrampe
- It all looks good. Maybe the activity “Send Human input to System” is a little bit too generic?
- You are asking yourself the right questions. I don’t have all the answer, as to answer your questions, you need to know the system you are designing, your goals, objectives, etc… It requires experience, and it is ok to try and then evolves things as you learn more. One thing I would say though: You have Capabilities, Processes and the Activities. But also keep in mind that Activities are hierarchical. So “Minimuse exposure to hazards” is most likely not going to be a leaf activity, but a mother one with sub-activities (and could be sub sub sub sub activities depending on the complexity of your system)
- Good question. It is not that it is bad. But Capabilities are described by scenarios and processes that are made of activities and exchanges. Also, Capabilities are contributing to the Mission. So one may ask: if this exchange is not required for the mission, by bother with it? If you have a good explanation for that, that is ok. Keep in mind that the same process (and questions) will happen at the SA/LA/PA level, so all the knowledge you are gaining here will be useful in the later stages as well. Reason why I am saying this is: Typically, V&V activities (testing plans) are driven by Functional Chains defined at SA Level. If one of your exchanges is not covered, then you are in danger that it will not be tested.
- Yes you can, that is the whole point of OPDs. Typically, to achieve question 4.
- I don’t know if you forgot anything. But I would not wait to transition to the SA, as there is not such thing like "waiting for a finalized OA to transition to the SA”. Going to the SA will make yourself ask new questions and realize that you may have forgotten things at the OA level, or put too many things, etc… It is a completely normal things to do both in parallel. And with the stakeholders.
All the best,
Stephane