A digital twin (DT) is both a digital shadow ―reflecting the status and operation of its physical twin and a digital thread―recording the evolution of its physical twin.

DTs not only help SAS system engineers, developers, and operators understand how such systems perform now―and in the future, but also facilitate their continuous integration and delivery.

Through effective representation of intelligent cyber-physical systems (CPS) ― physical (e.g., airport), conceptual (e.g., transportation system), or even software (e.g., digital cloud), DTs facilitate reasoning, what-if analyses, and decision making.