Availability of business applications is required for a company to stay competitive, productive, and profitable. Application users require availability or else the business suffers. Service providers must establish an infrastructure to support the availability requirements, or they may be subject to fines and penalties. Unavailability is visible to the organization, to the organization’s customers, and to the media. Attaining the desired availability does not happen by just installing lots of hardware or software. It must be planned, designed, and implemented using specific techniques.