What Are High Availability, Scalability, and Interoperability? The availability of hardware to users is a measure of how often it is online. A high-availability system continues running and performing at least 99 percent of the time. Scalability is the measure of how well computer hardware, software, or an information system can grow to meet an enterprise's increasing performance demands. An information system often must share information, or have interoperability, with other information systems within the enterprise.