====== Stale Alarms Report ======

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

{{ :alarm_analysis:stalealarmreport_01.png?direct&800 |}}

The picture above shows an example Stale Alarm Report.

By default, the report shows the Top 20 stale alarms (sorted by "Total On Time") for a defined reporting period (e.g. 1 Oct 2020 00:00:00 - 1 Nov 2020 00:00:00).

The calculated metrics are:

  * **Count:** Number of Stale Alarms / Total Number of Alarms, for reporting period. 
  
  * **Total on Time (days):**  The accumulated on-time of stale alarms.

===== Stale Alarm Detection =====

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. 

{{ :alarm_analysis.reports.stalealarms:stale-alarms-vis.png?direct&600 |}}
{{ :alarm_analysis.reports.stalealarms:stale-alarms-legend.png?direct&200 |}}

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).

Example 5 has no associated Alarm, therefore no on-time can be calculated and is therefore omitted.

Examples 6 and 7 transition outside the reporting period and are therefore **omitted**