Hi Lola,

I'm not sure exactly what you are asking, but let me try an answer. I am also unsure whether this is directly related to Papyrus as it appears to be more of a system/SCM architecture question.

When working on large systems, it is often a good idea to separate the model into multiple files ("modules"). this typically helps minimize (but not necessarily eliminate, conflicts when contributions ("check ins", "pushes", etc.) are made by the developers.

The way the model is segmented will depend on many things: architecture of the complete system, hierarchy of the components/modules, development team organization, platforms targeted, etc. The goals are typically to minimize dependencies in general and eliminate cross-dependencies (e.g., module A depends on module B that depends on Module C that depends on Module A) and to minimize conflicts when developers "check in" their changes. The dependencies, would be represented both as UML dependencies and relationships, but also as model imports (so that the module's elements are visible in the importing model). Note that a module should never have dependencies (import) to a module that is higher in the hierarchy.

Typically, each module will have their own diagrams. Modules that "contain" other modules will also have diagrams that show how they use the "sub-modules".

There would also be a single, "system" model that would show the dependencies at the highest level of the architecture.

Does that help?