Compositionality and CPS from a Platform Perspective

Cyber Physical Systems (CPS) comprise the integration of embedded computer systems and the physical processes that these computer systems interact with. Examples of such systems stretch from small embedded devices, e.g., intelligent sensor systems, to larger and often complex industrial systems, e.g., industrial automation systems. These systems are not only subject to functional requirements, but also non-functional requirements such as timing, resource usage, and reliability. CPS development (including software development) is substantially facilitated if the system parts can be developed and verified in isolation, and if the correctness of the system can be inferred from the correctness of its parts. Such modular and compositional design of software systems has for a long time been considered the holy-grail of system design, and is unfortunately only possible in selected scenarios. This paper covers one such scenario: using hierarchical runtime mechanisms in the platform to enable predictable resource usage and temporal isolation of CPS software. Our overall goal is to develop cost efficient mechanisms that are applicable for a wide range of systems.