A sub-alarm is an alarm that contributes to the status of a higher level virtual alarm. Sub-alarms can be grouped together, and the group itself can become a sub-alarm of a higher-level alarm. Each sub-alarm may or may not have the same status as its higher-level alarm. The effect of a sub-alarm’s contribution is determined by the way in which the higher-level alarm is configured. A sub-alarm’s contribution to a higher-level alarm can, in some cases, be modified.