We're all aware of the two mega-recalls of Toyota vehicles. The quick and easy explanation is that "cars are too complicated" and "cars have too many processors and too much software." Certainly, there is some truth to that (software-controlled cars creep me out), but the sticking-accelerator problem has nothing to do with electronics; it's a mechanical problem with a mechanical solution. But the real problem which designers of mass-market, high-volume products really face is the law of large numbers. When you have tens or hundreds of thousands of a product out in the market, some of its incredibly obscure and...