The SLA engine does not process manual outages in the same way as it does for real-time outages. While a real-time breach is created when real-time outage occurs, a breach is not created as a result of a manual outage. Therefore, there are no breaches corresponding to manual outages listed in Alarms view while viewing Historical > Outages.
However, manual outages are considered when calculating the SLA reports. Because manual breaches are simulated during report generation, and not queried breaches saved in the Service Warehouse, they are included in the SLA reports for any manual outages.