Examples of derived metrics include source lines of code per staff-hour, defects per thousand lines of code
, or a cost performance index.
As commercial software is developed, it typically contains 20 to 30 bugs for every thousand lines of code
, according to Carnegie Mellon University's CyLab Sustainable Computing Consortium.
* CMM-like process improvement efforts at Schlumberger have produced a variety of positive results, such as improving schedule adherence rates from 50% in 1990 to 99% in 1992, while reducing delivered defect rates from 0.22 per thousand lines of code
to 0.13 per thousand lines of code
It found that "Linux code averaged .17 bugs per thousand lines of code
Others showed how additional effort in the early stages of a project increased the number of lines generated by each programmer while reducing the number of errors per thousand lines of code