In our Definition of Digital Twins we have discussed our interpretation of digital twins, which is pretty compatible to the original definition that includes simulation, but is not reduced to simulation only.
There is one domain, namely the human medicine, where the term digital companion is used instead of digital twin. This is a smart move, because of course “twin” has a different connotation there, but it also reflects that the digital companion is actually in close contact with the physical system (including human, machine, process, etc.) to collect data and thus become an extended brain for the physical system. Moreover, the digital companion is an assitive system for the humans that can help in many situations, for example enabling the handicapped in their daily life, but also improving and simplifying daily processes in various forms.
We actually lean towards using the term digital companion for the piece of software that accompanies a physical system, collects the data and also interacts with the physical system for example by providing context information are also guiding and controlling the physical system. Therefore, the definition would be:
Definition: Digital Companion (aka. Digital Twin)
A digital companion of a system consists of
- a set of models of the system and
- a set of digital shadows, both of which are purposefully updated on a regular basis, and
- provides a set of services to use both purposefully with respect to the original system.
The digital companion interacts with the original system by
- providing useful information about the system’s context and
- sending it control commands.
All further discussions on this definition can be found at our above mentioned Definition of Digital Twins.