Use the Timeline to visually define and track the relationship between tasks. You can access the Timeline view by navigating to Plan > Planning Views and then through the default view or any of the saved views, select 'View as: Timeline'.
Viewing Items over a Timeline
The Timeline view will show any item in your product that has either a start date or end date or both.
Visualizing Item Dependencies
Items displayed on the Timeline view will visualize any dependencies they have with the relevant shape arrows. You can also set and edit dependencies directly from the Timeline view. An item can be either blocked by or block another item, alternatively, items can be related to each other.
A conflict where the blocking task start date is later than the blocked task start date will be displayed as follows:
You may set dependencies as follow:
Creating a New Item
To add a new item to your Timeline View, double-click anywhere you would like to add the item to.
Managing Relationships on Item level
The relationship between items can be set and managed at the item level. You can add related items via the Related Items section in the item's properties panel; You can then set the relationship type: Related, Blocked By or Blocks.
The number next to the Related Item icon below the description will indicate the number of related items.