1. Introduction
In software engineering (SE), there is no doubt that quality attribute requirements are an important and critical issue to improve the quality of the system [1]–[4]. However, many software developers and software engineers focus primarily on satisfying the functional requirements and rarely put much attention to meeting the quality attribute requirements [2]. Although conflicts among quality attributes are inevitable [1], software developers do not understand quality attribute requirements precisely [5]–[7]. Because the study for a consensus on the semantics of quality attributes is still lacking, it is difficult to understand the exact quality attribute requirements of the system in the SE process.