How alike are my physical and digital twins?

A digital twin is a virtual replica of a system defined at a certain level of fidelity, and synchronized at a specific frequency. Digital twins are often used to replicate physical systems whose simulations are usually computationally costly. One of the solutions proposed in the literature to this problem is to define a hierarchy of multi-fidelity digital twins, where we use one twin or another depending on the specific purpose. However, one of the challenges of this proposal is the need to determine whether these twins are equivalent to each other and the physical system according to their purpose. In this work, we explore different methods to measure this equivalence by analyzing the state and behavior of the twins using high-level software models.