Although I agree with you Murad on clearly establishing roles and responsibilities, I think that the scope is also important to acknowledge early on in order to make sure the team stays on track and doesn’t veer off course. Working out of scope can also cost the company a lot of money and resources by missing deadlines of the DDP. As someone else mentioned below, the Gantt Chart is useful for keeping track of the schedule in order to prevent delays. Therefore, I think the best is to initiate a kick off meeting where roles/ responsibilities and scope are determined first as well as discussing the Gantt Chart in order to make sure everyone on the team is on the same page and approves.