A New Metric of Adaptivity for Self-adaptive Systems

With focus on open-ended architectural adaptation, where individual components represent alternatives that can be added and removed dynamically at runtime, a new metric is proposed to provide insights on the effectiveness of architectural changes, such as the addition or removal of components. Specifically, the new metric allows to assess how much the system actually adapts to variations of the environment by properly applying a system reconfiguration. The approach is based on a statistical analysis of the system, which exploits the Bell inequality, conveniently adapted from the Quantum Mechanic theory. The formal definition of the new adaptability metric is presented, as well as an example of application in a simple case study.