Decomposição de requisitos de confiabilidade para sistemas autodaptativos utilizando o NFR framework

Abstract

Self-adaptive systems (SASs) can change their behavior at runtime according to their needs and problems, presenting dynamic and complex operations. One way to guarantee the quality of SAS is to correctly handle non-functional requirements (NFRs), such as security, usability and reliability. However, dealing with NFRs is naturally a difficult task, because they come into conflict and contradict each other. Other than that, NFRs are relative, and their interpretation can vary depending on many factors. Within the scope of SASs, there are also domain difficulties in addition to this natural difficulty. SASs have their characteristics directly linked to NFRs or quality characteristics that must be properly maintained for the system to work. Therefore, know-how these characteristics relate to NFRs becomes important. One way to deal with conflict problems within NFRs is to use SIGs (Softgoal Interdependency Graphs), basic units representing non-functional requirements or generic and flexible goals. The SIG concept was proposed by Chung et al. (2000) with the NFR framework concept. To support the implementation of NFRs in SAS and, consequently, contribute to improving the quality assurance of these systems, this work aims to propose a reliability SIG for SASs. In this work, a systematic mapping was carried out to provide an overview of the literature on the use of NFRs in SAS. At the end of the mapping, reliability was identified as one of the most recurrent characteristics in the selected studies. In addition, it was identified that reliability greatly impacts the functioning of SAS, which further motivated the choice of this characteristic. Then, the decomposition step of the reliability NFR was carried out, generating a reliability SIG for the SAS as a product. After that, the decomposition of the reliability NFR was carried out, generating as a product a reliability SIG for SASs.