In the Masterplan, when you hover the mouse on top of an activity name, a button appears as shown below:
Click on the button to add a new sub activity as the selected activity's child activity. Keep in mind that when a sub activity is added under an activity, this activity becomes a Parent activity of that sub activity.
[ A Parent activity's duration is non-editable, and is determined by the total duration of its sub activities. Parent activity's progress is also made up of the total progress of all of its sub activities. ]
Enter required details (Activity Name, Base and Expected Duration and Start Date) and click on Tick button.
The Masterplan will be updated once you click Tick.
Repeat the above process to create as many activities as needed and schedule the Masterplan in Lean PlanDo.
Note: Sub activity cannot be added to an activity with existing dependencies, either predecessor or successor. Existing dependencies need to be deleted before a sub activity can be added to the activity.
Watch the video below to learn how to add new activities under an existing activity from the Masterplan: