As I originally pointed out, Sigma software is physics based and goes deeper by determining what is going on behind the development of a defect, which is more useful in identifying future defects.
Senvol is all data driven (slide 39) and only looks for correlations between test samples/builds and post build testing to identify when defects are likely to occur in a similar build. Much more of a brute force and expensive method. Lots of test samples and post build testing.
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