>Hey Jim,
>
>>Do I think it is possible to produce zero-bug software? Yes, I do, and yes, I feel that MS is (at least since W2K was well under way) working toward that objective.
>
>The number of potential bugs is geometrically proportionate to the lines of code. When code is tested and subsequently revised, new bugs may be introduced or old bugs may reappear. Of course, everyone is working towards zero-bug software but some researchers consider it an impossibility with moderately complex code.
>
>In manufacturing, they strive for 99.9999% QA. I think it's called "sigma". 100% QA is considered unrealistic.

John,

Well I'll take a 99.9999% objective any day!
MS makes it even tougher on itself (no doubt customer demand has MUCH to do with this) in that they support a huge combination of versions/fix-levels of a HUGE number of individual and semi-independent "pieces" (components). I'm betting that MS will eventually reduce the number of semi-independent parts SIGNIFICANTLY in favour of delivering 99.9999% reliable software.