How to represent flows between business domains
I am looking for the best way to show two different kind of flows: flows inside a domain and flows between domains. The notion of a domain is not that important for this question, but the idea is that a domain bundles a set of business processes, applications and people and should for the most part be able to operate independently from the other domains.
There can be an arbitrary number of domains inside an organization.
Representing the domains and the intra- and inter-domain flows
One way to represent this, simply considering data flows between a couple of services is to draw a recursive flow relation:
The black flow represents a call inside the same domain, whereas the orange flow represents a call between two different domains.
However, that may be too abstract, especially when the flow requirements start to differ (e.g. a cross-domain flow must pass through a gateway). So a less abstract alternative could be the following:
Is that an acceptable way to represent flows between domains? I could perhaps add a 'generic' domain from which these two example domains are a specialization.
Specializing services per domain
As an extension to the above question, there may be situations where a generic application is set up that can be used by any business domain, to avoid that each domain must set up this application on its own (let's take the example of a message broker). Let's therefore assume this message broker application is not part of any domain. This generic message broker offers a message brokering service. However, even though the application along with the configuration etc. is not part of a domain, the actual service it provides must be.
In other words, there should be a message brokering service for each domain, since certain responsibilities must be taken up by that domain (e.g. managing the access control of that service). Therefore I have specialized them, and these specializations basically offer the same functionalities as the 'main' service.
Specializing them has another advantage, it makes it very clear that some calls from a service to the message broker occur inside the same domain (the black flow relations) and some occur cross-domain (the orange flow relations). If we would only have the main service, it would (IMO) be less clear.
An example representation would then be the following:
As you can see, the topics were also specialized for the same reasoning as the broker services.
Is this Archimate compliant? A there better ways to represent what I need?
Model attached: userForum.archimate