A milestone can be completed by completing all available modules linked to the milestone.
Completing a crash course, classic learning path, single learning, info booster or quiz.
Watching a video and marking it as complete.
Opening an external link
Completing a SCORM package
Being confirmed for an event by your administrator
Once a milestone is completed, the user progress of the milestone will be locked at 100%. After this happens, the user will not lose his completion if the milestone is adjusted.