I'm modelling part of a software architecture on which several processes run as a workflow. The architecture involves data parallelism, where a certain serial process produces N pieces of data which need to be distributed to N processes that must run in parallel.
I'm looking for a good way of expressing parallelism in a diagram. The objective of this diagram is to be informative and will be included in a paper about the system architecture. It does not need to be a formal model or strictly follow UML.
I've drawn 3 ways of representing the parallelism, one of which (2) basically follows the UML 2.0 Activity Diagram. I would like to know which one, if any, will more clearly convey the parallelism. What other information this sort of diagram should include?