This is exactly my request. In fact I would like an option to make a task "Dependent" on another task's completion. So it will remain denoted as pending until it's parent task is completed then it becomes available for completion. We have this a lot in our projects (Work needs to be completed by one team and the product passed to another team for additional work; the second team cannot start their work until the first is completed. If we could easily denote this in Workast, it would be very helpful.)