While implementing the deployer decision model I noticed that the two representations of Human Impact on the reference page appear to differ. I'd like to know which is normative.
The ssvc:HI:2.0.2 value definitions and the generated decision table ssvc:DT_HI:1.0.0 give different results for these combinations:
| Safety Impact |
Mission Impact |
HI:2.0.2 definitions |
DT_HI:1.0.0 |
| Marginal |
Degraded |
Medium |
Low |
| Marginal |
MEF Support Crippled |
Medium |
Low |
| Marginal |
MEF Failure |
High |
Medium |
| Critical |
Degraded |
High |
Medium |
| Critical |
MEF Failure |
no matching condition |
High |
The last row appears to be undefined in the prose. Low requires Safety Negligible. Medium requires (Negligible AND MEF Failure) or (Marginal AND Degraded/Crippled). High requires (Critical AND Degraded/Crippled) or (Marginal AND MEF Failure). Very High requires Catastrophic or Mission Failure. Safety Critical with Mission MEF Failure satisfies none of these.
I checked the Dryad calculator's standalone Human Impact model and it agrees with the decision table in all four cases.
One consequence, if the decision table is normative: Safety Impact Marginal produces the same Human Impact as Negligible for every Mission Impact value, so the four-value decision point behaves as three values for deployers. I wanted to check whether that is intended.
Which representation should implementers follow?
While implementing the deployer decision model I noticed that the two representations of Human Impact on the reference page appear to differ. I'd like to know which is normative.
The
ssvc:HI:2.0.2value definitions and the generated decision tablessvc:DT_HI:1.0.0give different results for these combinations:The last row appears to be undefined in the prose. Low requires Safety Negligible. Medium requires (Negligible AND MEF Failure) or (Marginal AND Degraded/Crippled). High requires (Critical AND Degraded/Crippled) or (Marginal AND MEF Failure). Very High requires Catastrophic or Mission Failure. Safety Critical with Mission MEF Failure satisfies none of these.
I checked the Dryad calculator's standalone Human Impact model and it agrees with the decision table in all four cases.
One consequence, if the decision table is normative: Safety Impact Marginal produces the same Human Impact as Negligible for every Mission Impact value, so the four-value decision point behaves as three values for deployers. I wanted to check whether that is intended.
Which representation should implementers follow?