Terms related to trustworthiness · 3.5.3
availability
the property of being reachable and usable on demand by a party that is authorised
What this term settles
This is the sense the standard gives availability. A firm is free to use another sense, but then the difference belongs in its own glossary rather than in an assumed shared language.
Who it binds
The entry has no shall in it, and the force of availability comes from use: once it appears in a procedure or a supplier term, this is the meaning the reader may rely on.
What to do in your practice
Take the firm's own definition of availability, put it beside this one and mark the differences. Each difference is either a deliberate local choice or an inconsistency to fix.
Evidence an auditor or regulator asks for
- A controlled vocabulary entry for availability with the citation 3.5.3, an owner and a review date.An auditor can check that availability is controlled rather than assumed.
- An assurance argument that links the property to the test, the review or the incident record behind it. The row names availability.Shows availability in use in the artefact the firm relies on, not only in a glossary.
- A register row with the owner, the date and the evidence reference for the claim. The record carries the availability entry and its date.The assurance case asserts the property without naming the test, review or incident record that supports it. The gap is tested against availability.
Common gaps this page catches
- availability is used in the assurance argument without a written definition, so two teams can mean different things.
- The entry for availability is reviewed when someone remembers, not on a cadence, so it drifts from the artefact it describes.
What to prepare before the amendment lands
Take the next policy revision and replace the loose use of availability with the entry and its citation. Record the change in the vocabulary change log.
How to test it here
Take one live artefact rather than a template, find the sentence or field where availability is used, and put this page beside it. Record the answer, the artefact and the date, because that record is the evidence and a glossary entry on its own is only an intention.
What this page does not claim
The page does not reproduce the standard, certify the firm or predict the wording the amendment will use; it states availability at the claim level "definition" and stops where the public record stops.
Common questions
- What does availability mean in ISO 22989?
- the property of being reachable and usable on demand by a party that is authorised
- What evidence should we keep for 3.5.3?
- A controlled vocabulary entry for availability with the citation 3.5.3, an owner and a review date. An assurance argument that links the property to the test, the review or the incident record behind it. The row names availability.
- Is availability a requirement?
- No: availability is a definition or clause of a terminology standard, and it becomes binding only when a firm writes it into a policy, a contract or a procedure, or when another standard incorporates it.
Related units
Source. ISO/IEC 22989:2022, Clause 3.5.3, Terms and definitions. Open the ISO public entry. Retrieved 21 October 2026.
https://www.iso.org/obp/ui/en/#iso:std:iso-iec:22989:ed-1:v1:en
ISO catalogue record 88145, the amendment status, stage and dates. Catalogue record 74296, the base standard.
Claim level: definition. The definition is in the public preview. This page states it in our own words and does not reproduce the text.
Last updated: 2026-10-21 · Markdown version · Check your vocabulary