Mary Jean Harrold 1 CS 4001D Spring 2004

Class 9

Questions, comments On-line discussion Term paper proposal Therac-25 paper Quick Quiz at end Assign

Readings Gift of Fire: Ch 3 (due 2/5) Assignment 8 (due 2/10) Term paper proposal (due 2/17)

Mary Jean Harrold 2 CS 4001D Spring 2004

Discussion

1. Do you think it is likely that throttles will disappear from airplanes and steering wheels and gas pedals will disappear from automobiles as more control is given to computer systems operated by the pilot or driver on a console or by voice? How soon do you think this might happen?

2. Which if the following models do you think would produce very accurate results? Which do you think would be less reliable? Give your reasons. Models that predict the effect of an income tax charge on government

revenue. Models that predict the position of the moon in relation to the earth, 30

years from now. Models that predict how much optical fiber will be needed in a major

city 30 years from now.

Mary Jean Harrold 3 CS 4001D Spring 2004

A factory contains an area where all the work is done by robots. The area is fenced and human workers are not supposed to enter while robots are working. When the fence is opened, it automatically cuts off power to the robots. A worker jumped over the fence to repair a robot that was malfunctioning. Another robot, bringing parts to the malfunctioning robot, pinned the worker against a machine, killing him.

Suppose your class is a consulting team hired (by a neutral party) to investigate this case and write a report. Consider several factors relevant in safety-critical software. What was done right? What was done wrong? Is there important information not included in this summary of the case that you would ask about? If so, what?

What degree of blame should be assigned to the software company that designed the robot system, the company that operates the factory, and the worker? Why? What changes, if any should the factory operators make to reduce the likelihood of more deaths?