UML22 — Ports in Protocol State Machines

Protocol machines should not have ports in them. It should be an
extension in the ports package. Otherwise there is a backwards
dependency onto composite structure.

Discussion
Statemachines already depend on ports via triggers, so the proposed change will not remove the dependency.
Furthermore, creating a dependency from composite structures to statemachines would create a more serious
layering problem. Therefore, resolving this dependency requires a non-trivial restructuring that shall be done
by an RTF at this point.
UML 2.5 has a different modular structure than UML 2.4 and earlier versions, with a single-level “flat”
structure in which inter-module dependency concerns, which are at the core of this issue, are no longer
relevant.
Disposition: Closed - No Change