Reliability, security & resilience · Core
Availability
Also called: service availability
ELI5
How often the service is working when needed.
Used in conversation
“Availability is measured at the customer-facing service boundary.”
Definition
The proportion of time a service is usable under a stated definition.
Here “Availability” means: The proportion of time a service is usable under a stated definition.
Pitch context
You will see “Availability” in product strategy decks, roadmaps, experiments and architecture reviews when the discussion reaches reliability, security & resilience.
Why it matters: In reliability, security & resilience, the scope can change what data may be used, who may access it and which controls are required.
Sources & evidence · 2
Direct term-level sources and supporting source families.
- National Institute of Standards and Technology — Computer Security Resource Center GlossaryDirect source · primary · checked 2026-08-16
- Scrum Guides — The Scrum Guide — official current versionSupporting source family · primary · checked 2026-08-16