An availability percentage needs a defined denominator. If no valid observations exist for the selected scope and period, there is no defensible availability value. Display “No availability data” rather than 100% or a green Healthy state.
When only some assets have observations, report availability for that covered scope and name the coverage limitation. Distinguish an unreachable service from a disconnected collector. Both matter, but they support different operational conclusions.
Choose a half-open report interval: the start is included and the end is excluded. Store exact UTC boundaries and retain the IANA display timezone. A local calendar day can contain 23 or 25 hours across a daylight-saving change.
Respect retention resolution. Daily summaries cannot recreate full-resolution historical samples or justify a percentile derived from averages. Keep observed facts separate from narrative recommendations and disclose when a requested detail no longer exists.
Prepared with AI assistance and checked against supported collection and reporting behavior. Verify device scope and permissions for your environment; no customer outcome or vendor endorsement is implied.