Availability
The proportion of time a system is accessible and able to serve its intended function.
Plain English
How often can users actually use it?
In context
Availability is usually measured over a time window and must define what counts as successful service.
Example
“The service reached 99.95 percent availability this month.”
When you'll hear this
- SLO planning
- incident review
- vendor evaluation
Common misunderstanding
Availability is one part of reliability and does not prove responses are correct.
Also known as
uptime
Commonly used by
Related terms
Updated: 2026-08-25
