Robustness: A natural Definition based on Nets-within-Nets

In modern distributed systems robustness is a major requirement. In previous work on availability, the analysis required an additional model part that specifies the assumptions about where in the model there are areas of unreliability. So, there are two models: the system itself and the error model. The error model usually requires specific domain knowledge. Therefore, the approach is not applicable outof-the-box. Instead, we like to derive an error model directly from the system model. We will show that for Elementary Object Systems we have a natural candidate to describe such a localised area of failure: the net-tokens. They are clearly localised and can be understood as computational entities (like containers in Kubernetes).