Enter units, opportunities and defects for one or more processes and get DPMO and the sigma level.
| Process | Units | Opp/Unit | Defects | |
|---|---|---|---|---|
| Process | Opportunities | Defects | DPO | DPMO | Yield % | Sigma | Rating |
|---|---|---|---|---|---|---|---|
| Assembly line A | 6,000 | 18 | 0.003000 | 3,000 | 99.700 | 4.25 | Good |
| Welding cell B | 2,000 | 30 | 0.015000 | 15,000 | 98.500 | 3.67 | Industry Average |
| Packing C | 4,800 | 7 | 0.001458 | 1,458 | 99.854 | 4.48 | Good |
| Overall (pooled) | 12,800 | 55 | 0.004297 | 4,297 | 99.570 | 4.13 | Good |
| Sigma level | DPMO | Yield % |
|---|---|---|
| 1.0σ | 691,462 | 30.8538 |
| 1.5σ | 500,000 | 50.0000 |
| 2.0σ | 308,538 | 69.1462 |
| 2.5σ | 158,655 | 84.1345 |
| 3.0σ | 66,807 | 93.3193 |
| 3.5σ | 22,750 | 97.7250 |
| 4.0σ | 6,210 | 99.3790 |
| 4.5σ | 1,350 | 99.8650 |
| 5.0σ | 233 | 99.9767 |
| 5.5σ | 31.7 | 99.9968 |
| 6.0σ | 3.4 | 99.9997 |
DPMO (defects per million opportunities) puts processes of different complexity on one scale: a part with 12 places where a defect can happen is not compared directly with a part that has 4. The calculator gives DPU, DPMO, the yield and the Sigma level for each process, and one combined figure for all of them.
Define the opportunities carefully and keep the definition fixed: counting more opportunities lowers DPMO without any real improvement.
The Sigma level uses the long-term convention of the published Six Sigma conversion tables, and the combined figure pools all processes correctly rather than averaging their sigma levels. The calculation is tested against the conversion table and a worked example.
The data behind “Try an example”: three processes.
| Process | Units | Opportunities / unit | Defects | DPMO | Sigma |
|---|---|---|---|---|---|
| Assembly line A | 500 | 12 | 18 | 3,000 | 4.25 |
| Welding cell B | 200 | 10 | 30 | 15,000 | 3.67 |
| Packing C | 1,200 | 4 | 7 | 1,458 | 4.48 |
| All processes | 1,900 | 55 | 4,297 | 4.13 |
Welding cell B has the most defects per opportunity and the lowest sigma, so it is the first target, even though Packing C makes more units.