Glossary · Reliability & operations
Availability
The proportion of eligible service interactions or time windows in which users can obtain the defined acceptable service under a stated measurement boundary.
Why it matters
A service can be running while users still cannot complete useful requests, so availability must be tied to user-visible success rather than process uptime alone.
In practice
Define eligible events and acceptable outcomes, exclude only documented cases, calculate the indicator over a fixed window, and investigate both total failures and prolonged partial degradation.
Common confusion
Availability is one reliability outcome. It does not describe latency, correctness, safety, or the experience of every user segment.
Related terms
Sources
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