Availability comprises 4 distinct components, which in combination, assure that system are running and business can be conducted.
•Manageability–the ability to create and maintain an effective environment that delivers services to users
•Recoverability–the ability to reestablish service in the event of an error or component failure
•Reliability–the ability to deliver service at specified levels for a stated period
•Serviceability–the ability to determine the existence of problems, diagnose their cause(s), and repair the problems