DPMO: Defects Per Million Opportunities
DPMO is a Six Sigma* calculation used to
the amount of defects in a process per one million opportunities.
To calculate: Total Number of Defects / Total Number of Opportunities for a
Defect. Then multiply the answer by 1 Million.
The challenge here is determining exactly what qualifies
as a defect. Some defects can pass through a quality inspection and have little
impact on the end product. Other defects can result in re-work or scrap.
DPMO is sometimes used instead of Defect per Unit to allow
for comparison between processes with different levels of complexity.
*Six Sigma uses statistical analysis to measure a
companies performance by identifying defects in a manufacturing process. The
goal of Six Sigma is to reduce process output variation to + or - six standard
deviations. This results in no more than 3.4 defects per million opportunities.