NumberOfComponents - NumberOfFaultyComponents <= AtRiskThreshold
As above condition does not hold true, an event is not generated.
The complete AtRisk logic checks for few other alarms and parameters as well before giving AtRisk as follows:
if (NumberOfComponents > 0)
check (!IsGroupPartOfSingleUnresponsiveSystem &&
IsAnyComponentDown &&
!IsEveryComponentDown &&
NumberOfComponents - NumberOfFaultyComponents <= AtRiskThreshold);