Research Article
Fuzzy Risk Graph Model for Determining Safety Integrity Level
Table 2
Example of qualitative and quantitative definitions of parameters.
| | Risk parameters | Qualitative descriptions | Quantitative descriptions |
| | Consequence () | Minor injury
| No deaths per event | | Marginal:
one death or permanent injury
| probable deaths per event | | Critical:
several deaths
| probable
deaths per event
| | Catastrophic:
many deaths
| >1 probable
deaths per event
|
| | Exposure () | Rare | <10% of time | | Frequent | ≥10% of time |
| | Avoidance () | Possible | >90% probability
of avoiding hazard
| | Not likely | ≤90% probability
of avoiding hazard
|
| | Demand rate () | Very low | <1 in 30 years
<0.03 per year
| | Low | 1 in years per year
| | Relatively high | 1 in years per year |
|
|
