Incidents allow you to schedule one-time or recurring maintenance windows and annotate unplanned outages for one or more collections in ArcGIS Monitor. To accurately calculate metrics, monitoring and alerting should be turned off for scheduled maintenance and the duration of incidents should be edited to reflect the incident's actual length of time.
If you need to perform routine maintenance on a subset of components in one or more collections, you can create a collection that only contains the components that require maintenance. You can then create an incident for the new collection and turn off monitoring and alerting. This ensures that the remaining components in your existing collections aren't affected. This can also be applied to incidents for unplanned outages.
You can configure a reminder that displays a banner at the top of all collection and component pages associated with the incident to remind Monitor users of upcoming and active incidents. When an incident is active, an Incident button appears on all affected collection and component pages; you can show more information about the incident by clicking the Incident button. You can also configure email and webhook notifications to be sent to the collections' subscribed users to notify them of the incident.