Quality of service requirements fall under which category of requirements?

Quality of service requirements are categorized as non-functional requirements. Non-functional requirements describe how a system performs its functions rather than what functions it performs. These requirements address aspects such as usability, reliability, performance, security, and maintainability, which directly contribute to the overall quality of the service delivered by the system.

For instance, quality of service requirements may specify a certain level of response time, availability, or throughput that the system must meet to ensure a satisfactory user experience. Unlike functional requirements, which define specific behaviors or functions of the system, non-functional requirements focus on the attributes that enhance the effectiveness and efficiency of those functions. This distinction is crucial in ensuring that while the system meets its functional goals, it also adheres to expected quality standards that determine user satisfaction and system performance.