Non-Functional Requirements (Usability, security)

Abstract

Ideally the use of software is determined by the performance of both its functionality, such as its usefulness, flexibility, functionality, synergy, security. However, there has been a third-party emphasis on software performance, even if the functionality is not helpful or used without he necessary non-functional features. we discuss the state of the art in the design of non-functional requirements (hereafter, NFRs), while providing hope for some future directions.