Definition: Stale alarms are alarms which are/were on for 24 hours or more.

For a defined reporting period (e.g. 1 Oct 2020 00:00:00 - 1 Nov 2020 00:00:00) the identified the Top 20 worst offending stale alarms.

The calculated metrics are:

• Count: Number of Stale Alarms / Total Number of Alarms, for reporting period

• Total on Time (days): The accumulated on-time within the reporting period that is attributed to stale instance of the alarm.

Alarm Analysis operates on Reporting Periods. That is, Alarm Analysis compiles metrics for a given date-range and will only detect a Stale Alarm if it transitions (annunciates or returns) within the reporting period.

With reference to the above illustration, the Stale Alarm report includes alarms that…

• were on for 24 hours in the selected period (1).
• transitioned after 24 hours (or more) in the selected period (2,3)
• were on for longer than 24h but haven't returned to normal within the selected period (4).
• were on for longer than 24h but haven't started inside the selected period boundaries (5).

Examples 6 and 7 transition outwith the reporting period and are therefore omitted