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PHP 5.3 (538 KLOC), and PostreSQL 9.1 (1106 KLOC). Figure 10.5 shows
how the defect density can vary (Coverity 2011). Note that the defect densities
reported by Coverity in these three open source systems are approximately
100 times lower than defect densities reported in commercial systems 25
years ago (Grady and Caswell 1987).
Defect density is certainly an acceptable measure to apply to your proj-
ects, and it provides useful information. However, the limitations of this
metric were made very clear in prior chapters. Before using it, either for
your own internal quality assurance purposes or ...