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How about the SpaceX tank struts? These were presumably designed with the aid of a computer, and were not as strong as they were needed to be.

The news stories focused on testing, but testing is kind of the emergency fail safe of product construction. The fix involved a redesign, not more testing, so it seems safe to say the initial design was a failure.

It is also possible that the requirements were off.

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From their investigation, http://www.spacex.com/news/2015/07/20/crs-7-investigation-up...:

The strut that we believe failed was designed and material certified to handle 10,000 lbs of force, but failed at 2,000 lbs, a five-fold difference.

I could read that as either evidence that the CAD computations were wrong, or evidence that something completely different happened. For example, someone might have taken a shortcut in manufacturing.

Most of the struts performed to spec, with a fraction of a percent failing under much less force than they should have. That sounds like a manufacturing problem, not a design problem.

What I heard from a friend of a friend is that QA was not handled as well as it could've been.

I think that's why PG specified "general-purpose CAD tool", in order to exclude in-house software.

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