Workload. According to the ECTS Users' Guide "workload indicates the time students typically need to complete all learning activities (such as lectures, seminars, projects, practical work, self-study and examinations) required to achieve the expected learning outcomes" (2009, p. 11).
According to ECTS, 30 hours of student work correspond to 1 credit point (CP). One semester covers 30 CP with 20 weekly contact hours (WCH) on average. That results in a semester workload of 900 hrs for full-time students.
Self-study. As layed out in the Resources-Engineering Workload Plan, students are expected to spend time during the semester parallel to course sessions. This self-study serves to prepare for classes and to revise notes for examinations.