This report uses a weighted average to calculate node availability. This may be useful in circumstances where you may prefer to configure the maximum weight to filter out records that happen after the polling marks the node down or the node was unmanaged. This report should be used with detailed response time records only as hourly and daily records will be aggregated using normal averages.
For more information on how Orion calculates Status and Availablity visit https://documentation.solarwinds.com/en/success_center/orionplatform/content/core-calculating-node-availability-sw1184.htm