Viewing task dependencies on the timeline
Tasks that depend on one another are connected visually on the timeline so you can see how a delay in one task affects others. This article covers reading dependency lines.
Reading dependency lines
Open Timeline — any task with a dependency shows a connecting line running from the end of the task it depends on to the start of the dependent task. Following a chain of lines left to right shows the order tasks are expected to complete in.
Dependencies are view-only here
The timeline is a good place to see how tasks relate to each other, but you can't create or edit a dependency by dragging on it — links aren't drawn or reconnected from this view, and you can't drag a task's progress indicator either.
To add or change a dependency, open the task from its Task Board and set it there. See Setting task due dates and dependencies.