The Daily Parker

Politics, Weather, Photography, and the Dog

When software bugs kill

The Daily WTF today takes us back to one of the worst software bugs in history, in terms of human lives ruined or lost:

The ETCC incident was not the first, and sadly was not the last malfunction of the Therac-25 system. Between June 1985 and July 1987, there were six accidents involving the Therac-25, manufactured by Atomic Energy Canada Limited (AECL). Each was a severe radiation overdose, which resulted in serious injuries, maimings, and deaths.

As the first incidents started to appear, no one was entirely certain what was happening. Radiation poisoning is hard to diagnose, especially if you don't expect it. As with the ETCC incident, the machine reported an underdose despite overdosing the patient. Hospital physicists even contacted AECL when they suspected an overdose, only to be told such a thing was impossible.

With AECL's continued failure to explain how to test their device, it should be clear that the problem was a systemic one. It doesn't matter how good your software developer is; software quality doesn't appear because you have good developers. It's the end result of a process, and that process informs both your software development practices, but also your testing. Your management. Even your sales and servicing.

While the incidents at the ETCC finally drove changes, they weren't the first incidents. Hospital physicists had already reported problems to AECL. At least one patient had already initiated a lawsuit. But that information didn't propagate through the organization; no one put those pieces together to recognize that the device was faulty.

On this site, we joke a lot at the expense of the Paula Beans and Roys of this world. But no matter how incompetent, no matter how reckless, no matter how ignorant the antagonist of a TDWTF article may be, they're part of a system, and that system put them in that position.

TDWTF's write-up includes a link to a far more thorough report. It's horrifying.

Comments are closed