What is a Digital Twin?

The first idea of Twin appeared at NASA with its Apollo program. At that time, it was a real copy of the module where it was possible to reproduce the problems encountered in space by the module and find a way to solve them from the earth. Grieves introduced the transformation into a Digital Twin in 2003 as mentioned in “Digital Twin: Manufacturing Excellence through Virtual Factory Replication”. NASA and the US Air Force then started to apply the Digital Twin in the aeronautic domain.

Since then, the concept of Digital Twin continuously evolved, passing from a three-dimensional Framework to a five-dimensional Framework. The 3Dimensional Framework was composed of the Physical Entity, that is the real physical object; the Virtual Entity consisting of a set of models, that are geometry model, physics model, behaviour model, and rules model; the Connections of data and information that bind the physical and Virtual Entity together.