Scoring system for likelihood of occurrence (O) used in FMEA
| Likelihood | Data | Score | Probability |
|---|---|---|---|
| Remote | No known occurrence | 1 | 1/10000 |
| Low | Possible but no data | 2–4 | 1/5000 |
| Moderate | Documented but infrequent | 5–6 | 1/200 |
| High | Documented and frequent | 7–8 | 1/100 |
| Very High | Documented, almost certain | 9–10 | 1/20 |