Using RELAX, SysML and KAOS for Ambient Systems Requirements Modeling

Ambient Systems are highly adaptive. They modify their behavior at run-time in response to changing environmental conditions. For these systems, Non Functional Requirements (NFR's) play an important role, and one has to identify as early as possible the requirements that are adaptable. Because of the inherent uncertainty in these systems, goal based approaches can help in the development of their requirements. Relax, which is a Requirement Engineering (RE) language for adaptive systems, can introduce flexibility in NFR's to adapt to any changing environmental conditions. We illustrate our proposal through a case study of an Ambient Assisted Living (AAL) system. We use an existing goal oriented approach, based on Kaos, which extends the SysML 1meta-model and our proposed Domain Specific Language (DSL) for Relax; that enables to derive requirements in graphical format from textual requirements in the form of SysML requirements diagrams. In this paper we show how we have integrated these two approaches for a better modeling of these systems