A related cause of accidents is failure of control software, as in the cases involving the Therac-25 medical radiotherapy equipment: the elimination of a hardware safety interlock in a new design model exposed a previously undetected bug in the control software, which could have led to patients receiving massive overdoses under a specific set of conditions.
Srodan uzrok nesreća je kvar software-a, kao u slučajevima koji su uključivali Therac-25 medicinske radioterapijske opreme: eliminacija hardware-skog sigurnosnog zaključavanja u novodizajniranom modelu otkrila je prethodno neopažen bug u kontrolnom software-u, koji je mogao dovesti do toga da u određenim okolnostima pacijenti prime velike prekomjerne doze.