Exploring anomaly detection in systems of systems

The loosely coupled interoperability of heterogeneous existing systems, together with the ongoing replacement of monolithic systems design with Off-The-Shelf (OTS) approaches, promotes a new architectural paradigm that is called System of Systems (SoS). In SoSs, independent and autonomous constituent systems (CSs) cooperate to achieve higher-level goals. Some inherent challenges are that boundaries of the SoS may be partially unknown and the components may be governed by different authorities, affecting the ability to observe the system as a whole. Further, novel challenges related to dependability and security are introduced, such as the detection of emerging and possibly unexpected behaviors resulting from the interconnection of previous disconnected CSs. In this paper we explore these challenges questioning if a novel mindset to error, malware or intrusion detection is needed when dealing with SoSs. With the support of a state of the art review, we first identify the design principles and the performance targets of a monitoring and anomaly detection framework. Then we discuss these principles at the light of SoS fundamentals. Ultimately, we propose an approach to design a monitoring and anomaly detection framework for SoSs aggregating i) monitoring approaches ii) SoS properties, and iii) anomaly detection techniques.