What is the primary focus when defining non-functional requirements?

The primary focus when defining non-functional requirements is on the qualities that characterize how the system performs its functions rather than what specific functions it performs. Non-functional requirements address attributes such as performance, usability, reliability, security, maintainability, scalability, and compatibility. These qualities are crucial as they directly influence user satisfaction and overall system effectiveness.

For instance, performance requirements may specify the response time of the system under certain conditions, while usability requirements may define how intuitive the user interface should be. By focusing on these aspects, non-functional requirements help ensure that the system not only meets its intended functionalities but also provides a positive user experience and operates well within its intended environment.

In contrast, other choices involve aspects of the system that are more aligned with functional requirements or project management. Specific functionalities, integration with other systems, and stakeholder engagement strategies primarily concern what the system should do and how to manage its development, rather than how it should operate or be perceived by the end users.