“Can’t we shorten a project plan by looking at the dependencies and starting some releases in parallel with others? Of course we could, but in doing so, we increase project risk. When working on several unrelated pieces of software at the same time, the individual developers may only work on one thing at a time, but the managers and the testers and especially the stake holders who are thinking about functionality and exercising change control are overloaded, so they will make poorer decisions.