Description: Operational availability is the degree to which a network service is operational and accessible to users. This concept is fundamental in the realm of quality of service (QoS), as it determines a system’s ability to function continuously and without interruptions. Operational availability is typically measured as a percentage of the total time a service is available compared to the total time it should be available. A high level of availability is crucial for ensuring user satisfaction and operational efficiency within organizations and systems in general. Key characteristics of operational availability include system redundancy, fault recovery capabilities, and constant monitoring of service status. In a business environment, high operational availability can translate into a competitive advantage, as it allows organizations to provide uninterrupted and reliable services to their users. Therefore, operational availability is not only an indicator of a system’s health but also an essential component of risk management and business continuity strategies.