01 · Purpose
Why and when to use it
Use it when distinct defect opportunities are meaningful and defined consistently. It compares opportunity-based burden rather than simply the proportion of defective units.
Who takes part?
The measurement owner works with people who understand the process and the recorded data. Statistical or measurement-system decisions should involve someone able to check the assumptions and study design.
02 · Application
How to apply it
Start with an agreed measurement purpose, explicit units and trustworthy observations. Identify missing cases and assumptions before calculating.
- Define the unit and each eligible defect opportunity.
- Record units, opportunities and defects consistently.
- Use the actual total eligible opportunities if they vary by unit.
- Divide defects by opportunities and multiply by one million.
- Report the opportunity definition and distinguish defects from defective units.
03 · Example
A worked measurement example
Original fictional teaching example. Small datasets illustrate the method; they are not proposed as sufficient study sizes. Supplied parameters are assumptions, not estimates from a real process.
| Illustrative input / result | Value |
|---|---|
| Units / opportunities per unit | 100 orders / 3 checks: part, quantity, label |
| Defects / total opportunities | 12 / 300 |
| DPMO | 12 / 300 × 1,000,000 = 40,000 |
04 · Interpretation
What the result tells you
A 40,000 DPMO result is a 4% defect rate per defined opportunity. It is not necessarily 4% defective orders because an order may fail multiple checks.
Completion check: An opportunity-based defect rate with a transparent denominator.
05 · Judgement
Mistakes and limitations
Adding artificial opportunities makes DPMO look better. Comparisons require comparable opportunity definitions; do not automatically convert DPMO to a sigma level using an unstated shift convention.
07 · Reading
Sources and further reading
The tool list follows the accepted LeanTrainingLab overview and its reference to Six Sigma+Lean Toolset, second edition (Lunau, editor; Springer, 2013). The book chapters were not available for direct review during this build. Explanations, examples and worksheets are original teaching material. Further reading supplies professional background; local conventions are stated explicitly.