
The predecessor is really used for scheduling, but it is not a "hard" dependency meaning that t2 can still be completed even if t1 is not complete. In order to make these hard dependencies, you would have to create a small validation rule that would prevent tasks from being marked as complete if there are any active predecessors. This is something that can either be done with your CSM or demonstrated on an advanced Q&A forum ( http://www.clarizen.com/live-demo.html)