> "Stable" [...] means that you have a mean and variance And software development, as a process, does not have a (finite) mean or variance. > I think bugs sho

> "Stable" [...] means that you have a mean and variance And software development, as a process, does not have a (finite) mean or variance. > I think bugs should be stable if you normalize it by a size metric. Bugs approximately follow a heavy-tailed distribution, such that as the number of samples increases, the empirical average work to fix (and possibly other measures of severity) does not converge to any finite value, but instead increases without bound. (I think roughly logarithmicly, but don't quote me on that.) In particular, it doesn't satisfy the requirements of the central limit theorem, so a lot of statistical techniques work poorly or not at all on software projects that are large enough, individually, to do statistics on (as opposed to doing statistics on populations of software projects, which seems to mostly work, usually).