Towards modelling and analysing non-functional properties of systems of systems

Systems of systems (SoS) are large-scale systems composed of complex systems with difficult to predict emergent properties. One of the most significant challenges in the engineering of such systems is how to predict their Non-functional Properties (NFP) such as performance and security, and more specifically, how to model NFP when the overall system functionality is not available. In this paper, we identify, describe and analyse challenges to modelling and analysing the performance and security NFP of SoS. We define an architectural framework to SoS NFP prediction based on the modelling of system interactions and their impacts. We adopt an Event Driven Architecture to support this modelling, as it allows for more realistic and flexible NFP simulation, which enables more accurate NFP prediction. A framework integrating the analysis of several NFP allows for exploring the impacts of changes made to accommodate issues on one NFP on other NFPs.