As detailed in each study program's Studien-und Prüfungsordnung (Curriculum and Examination Regulation), students must write a final bachelor or master thesis in order to graduate. This thesis, supervised by a professor, is prepared in many cases outside the University as project in a company.
If the student has exceeded the maximum program duration, but the thesis is the only study credit outstanding in order to graduate, it is possible to finish it as "Externer Examenskandidat" (external candidate). For this, the student de-registers at his / her own request at the end of the semester, but the thesis can be handed in within two more semesters after deregistration. The candidate is not registered as a student, does not need to apply for extension of the program duration, and does not need to pay further study fees.