>>Do I think it is possible to produce zero-bug software? Yes, I do,
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>I disagree, and so does the rest of the professional software testing industry. You can hit a piece of code 10K times, and it may be the 10K+1th time that it fails. You can do code coverage and think that a piece of code is unreachable, but your customer will find a permutation that reachs that code. In a complex system, there are enough possible permutations that you could spend a lifetime testing it.

My understanding is that it is possible to create bug-free software. I remember reading an article a number of years ago in the late, lamented Byte magazine which was titled, IIRC, "Demonstrably Correct Programming". Apparently a university group in England developed a language that could be used in narrow, critical domains (e.g. air traffic control) to eliminate bugs. However, I believe it included its own real-time OS, not a large general-purpose OS like Windows.

You claimed on another branch that you're able to crash your microwave and other embedded devices. That, I find surprising and interesting. I'd be interested to find out, in general terms, how your testing methods compare to those of the embedded/real time markets, whether you have much in common, etc.

My understanding is that testing for embedded/real time systems is the most stringent anywhere, because the consequences of bugs are so severe. At the very least, if low-cost consumer items like microwaves need to be recalled it totally destroys all profit for the product. Liability can be far worse than that e.g. those patients who were fried with massive, fatal X-ray overdoses. Then, you've got your Mars landers...

I totally agree with you that expecting 100% bug-free code in consumer software on a general-purpose OS is unrealistic at present. And stamping out every known, esoteric bug would probably price the product out of its intended market. As an engineer I'm very aware of this, when a product should be "good enough".

However, it would be nice to think that perhaps embedded/real time design, and testing techniques could be applied to more consumer and systems software (if they're not already).