Asynchronous subprocesses and communication

Hi @Niall,

please find here conceptual design. In general we have a problem how to inform main process about changes in subprocesses. Subprocesses can be different depending on the object type, that is why I drew two of them.
We also want to start subprocesses, but not wait for them synchronously, but receives events about progress of their work. I think this can only be achieved with message start event, right?