Availability means that Correct Data is available when required.
Correct Data requires Integrity of the data to confirm that only Authorised people have changed it.
Authorisation requires the Authenticated individuals.
Authentication requires a Shared Confidential secret.

While Compliance with regulatory standards is a cost to the business, the Availability of information will often be of critical importance to a business.

Availability can be used to drive any Information Assurance activities.