DPMO View

What is the need to view defects "per million", can % view not suffice?

Defects per million gives a better insight into defect severity. This magnifies defects and makes the performance look better (if the process is efficient). For example, you can talk that your process has only 1% defects. When talking in terms of percentage, the severity of defects does not seem much. Defects look manageable!!!

Parts per million magnifies the defects and shows a more realistic picture. When translated to PPM, 1% is equal to 10, 000 defects per million! Now this seems too big a value to neglect.

Instead of PPM, a better way to denote variation is by calling points as defects. Thus, we have DPMO (Defects per million opportunities) instead of PPM.