Milestones can be linked to the lifecycle phases in the Projects or Transformation items Fact Sheets.
The lifecycle field has a new date selector represented by the calendar icon. On clicking the icon, users get an option to select between the absolute date 'Date picker' and 'Milestones.' By default, it is set to the absolute date. If milestones are to be linked to the lifecycle phase, the date selector has to be switched to 'Milestones.' If a milestone date changes, it will automatically update all the dates of the projects that depend on it. This functionality enables managing the dependency of certain projects with the milestones from the same or different projects.
For more details about this feature, please refer to the 'Dependencies of milestones in lifecycle' section in LeanIX user documentation.