Which metric expresses defects per million opportunities in Six Sigma?

Which metric expresses defects per million opportunities in Six Sigma?

• A. Throughput per hour
• B. Yield Percentage
• C. DPMO
• D. Defect Rate per Unit

Answer: (C)

In Six Sigma, the metric that expresses defects per million opportunities is DPMO. It measures quality by counting how many defects occur relative to how many opportunities there are for a defect, then scales that ratio to a million to allow fair comparisons across processes of different sizes or designs. DPMO is calculated as defects divided by opportunities, multiplied by 1,000,000. Here, opportunities mean every place a defect could occur in the process for every unit produced—for example, if a product has several features that could fail and you process many units, you count all potential defect locations across all units. This metric best fits the concept because it accounts for both the number of defects and the complexity or number of opportunities for defects. The other options don’t normalize defects to the amount of potential failure points: throughput per hour measures production rate; yield percentage looks at good output versus total input without considering defect opportunities; and defect rate per unit reports defects per unit, which can vary with unit size or number of opportunities. DPMO provides a standardized, comparably scalable measure of quality, useful for benchmarking and aiming for Six Sigma levels (often around 3.4 defects per million opportunities). Example: if there are 2 defects in 1,000 total defect opportunities, DPMO = 2/1000 × 1,000,000 = 2,000 DPMO.

In Six Sigma, the metric that expresses defects per million opportunities is DPMO. It measures quality by counting how many defects occur relative to how many opportunities there are for a defect, then scales that ratio to a million to allow fair comparisons across processes of different sizes or designs.

DPMO is calculated as defects divided by opportunities, multiplied by 1,000,000. Here, opportunities mean every place a defect could occur in the process for every unit produced—for example, if a product has several features that could fail and you process many units, you count all potential defect locations across all units.

This metric best fits the concept because it accounts for both the number of defects and the complexity or number of opportunities for defects. The other options don’t normalize defects to the amount of potential failure points: throughput per hour measures production rate; yield percentage looks at good output versus total input without considering defect opportunities; and defect rate per unit reports defects per unit, which can vary with unit size or number of opportunities. DPMO provides a standardized, comparably scalable measure of quality, useful for benchmarking and aiming for Six Sigma levels (often around 3.4 defects per million opportunities).

Example: if there are 2 defects in 1,000 total defect opportunities, DPMO = 2/1000 × 1,000,000 = 2,000 DPMO.