SQAL Self-Adaptive System's Quality Assurance Language

Today's software systems tend to be flexible and dynamic by provisioning mechanisms to react quickly to the environment changes and to adapt system configuration accordingly, in order to maintain the required quality of service (QoS). The engineering of system self-adaptation requires new modeling methods and development methodologies that employ the principles of model-driven development in building self-adaptive systems (SASs). To tackle this issue, the present work proposes SQAL (self-adaptive system quality assurance language) a domain specific language for quality-aware SASs. This language allows describing SASs architectural elements and the corresponding interrelations in terms of hierarchical compositions. It also provides concepts for defining SASs behavioral aspects by identifying adaptation actions and mainly weighting them with QoS parameters. SQAL is defined in terms of its abstract and concrete syntaxes. This article associates a PSMaude-based semantics to SQAL in order to quantitatively analyze quality-aware SASs behaviors.