The paper presents an approach to help staff responsible for running courses by identifying key milestones in the educational process, where the paths of successful and unsuccessful students started to split. By identifying these milestones in the already finished courses, this information can be used to plan the interventions in the next runs. This is achieved by finding the earliest time when the differences in behaviour or key performance metrics of unsuccessful students start to become significant. We demonstrate this approach in two case studies, one focused on a course level analysis and the latter on a whole academic year. This suggests its generic nature and possible applicability in various Learning Analytics scenarios
