Toward a Performance Requirements Model for the Early Design Phase of IT Systems
Ahmad Alwadi, Abdulrahman Nahhas, Sascha Bosse, Naoum Jamous, Klaus Turowski · 2018
The importance of the Quality of Service (QoS) is widely acknowledged due to the increasing shifting towards client-oriented IT services. The QoS attributes of any IT system are strongly characterized by its Non-Functional Requirements (NFRs). It has been well-recognized that the NFRs are invariably more problematic and more expensive to meet in the later stages of the system lifecycle. Therefore, the desired NFRs have to be built-in during the earliest phases of a system lifecycle. Although the significance of quality attributes (NFRs) is becoming more acknowledged worldwide, a specific conception and treatment regarding NFRs continue to be not sufficiently examined and poorly understood. Among various NFRs, performance is considered to be one of the most pervasive NFRs in the system since some performance aspects are concerns that permeate the dominant decomposition of the system as well as a range of the system's functionalities. For years, it has been emphasized that insufficient or contrary determination of performance requirements has a critical impact on the IT system quality. Performance obstacles still often exist due to essential misconceptions in the requirements during the design phase. In order to investigate the earlier stated challenges, in this research, a comprehensive overview on the state-of-the-art quality models and various classification schemas in general and their treatment of performance, in particular, will be presented. Based on current understanding of performance and the findings of the analysis, a performance requirements model is proposed.