 Nancy Leveson gained her degrees (in computer science, mathematics and management) from UCLA, including her PhD in 1980.Previously she worked at University of California, Irvine and the University of Washington as a faculty member.She has studied safety-critical systems such as the Traffic Collision Avoidance System (TCAS) for the avoidance of midair collisions between aircraft and problems with the Therac-25 radiation therapy machine.