Conflicts among non-functional requirements for robotic systems heavily depend on features of actual execution contexts. The main objective of this work is to design and experimentally evaluate a framework, called SCARS, providing: (a) a domain-specific language extending the ROS2 Domain Specific Language (DSL) concepts by considering the different environmental contexts in which the system has to operate, (b) support to analyze their impact on non-functional requirements, and (c) the computation of the optimal degree of non-functional requirement satisfaction that can be achieved within different system configurations. The effectiveness of SCARS has been validated on the Gazebo simulation for iRobot ^® Create ^®3 robot.