(2)? Reliability requirements: users' requirements for the frequency, severity, recoverability and predictability of software failures.
(3)? Ease of use requirements: user's requirements for ease of use and aesthetics of the interface, as well as user-oriented documents and training materials.
(4)? Security requirements: users' requirements in authentication, authorization control and privacy.
Extended data
With the increase of scale and complexity of software system, non-functional requirements have gradually become a new focus of software engineers. In the early stage, Party A has requirements for the system, such as development platform, technical genre and key implementation. Based on my understanding of software technology and my consideration of the convenience of system file maintenance, this is called "design constraint".
Judging from the contract between Party A and Party B, design constraint is also a kind of demand-a kind of "non-functional" demand. Later, the quality problem of software became more and more prominent, and the requirement of describing software quality objectives became a part of non-functional requirements. Therefore, the non-functional requirements for software in the industry generally include: quality attribute requirements and binding requirements.