if the course doesn't depend on time and the content of the course doesn't change, then using topic based course may make the course re usability easier by grouping the user. By combining topic based course with conditional activity, you may be able to have the student complete certain task before unlocking the next task.
If the course rely on time (For example, activity or assessment must due for a certain date), then restoring the course may be the answer.
regards,
Riady