User guide / Tasks / Subtasks and milestones
Managing a projectSubtasks and milestones
Split a task into subtasks and mark key deadlines with milestones.
1 min read updated October 2026
A task that is too broad can be split into subtasks; an important deadline is marked with a milestone.
Subtasks
A subtask is a task in its own right (assignees, dates, status), attached to a parent task.
- 1Open the task to split.
- 2Add a subtask from its sheet, or directly below the task in List view.
- 3Enter its title, assignees and dates.
The parent task's progress is calculated from its subtasks: it goes up as they are completed.
Milestones
A milestone marks a key deadline: steering committee, delivery, approval. It has no duration, just a date. In the Gantt chart, it is shown as a diamond; in the calendar, on its date only.
Project milestone
A deadline specific to the project, created like a task and marked as a milestone.
Reference milestone
A stage shared by the whole organisation (for example "Kick-off" or "Closure"), defined by the administrators and marked with a halo in the Gantt chart.
Good to know: the dashboard's Milestones widget shows the project's next deadlines, with a badge if one of them is late.
Frequently asked questions
Does a subtask appear in "My tasks"?
Yes, if it is assigned to you, like any task.
Can I turn a task into a milestone?
Yes, from the task's sheet, by marking it as a milestone.