question

You know that this model just works once. You create a token for each process row, that fills the rack, then if the rack is full the process empties the rack. And then there isn't any token left that can do anything in your processes at all. You need more transporters in your groups and you need more tokens moving in your processes. You have build a single sequence of activities in each row, in which only one token flows from one activity to the next.