advise me if I must open a new topic. I have obtained a great result thanks your help.
Starting from this model, I'd like to describe a more complex situation:
I'd like a source that produces simultaneously batches of entities with different name; Do I need a flow control with a buffer for each entity type? I suppose I need a Entrance Control (I can't write it) in parallel process beacuse I want a FIFO strategy, but always respecting the previous rule of empty/full buffer. If more than one predecessor buffer is full, I desire that entities that are waiting for more time enter in the parallel process.