Modeling activities conducted by different roles

Hi

To represent parallel process, the norm is to use a JUNCTION as this allows you to have one line flowing to the junction and multiple lines leaving the junction. However if your question is about how you model two roles, in the same model, performing the same task, at the same time, then you could probably use the RESOURCE tab by double-clicking on the activities.

Does this help? Otherwise you could consider dimensions, but that requires further explanation.