— This document analyses the overall configuration of an industrial digital twin system, and proposes a three-elements architecture, focusing on the twinning interface between the physical twin (PTw) and industrial digital twin (iDTw).

— The characteristics, and the visualization elements and visualization fidelity of iDTw are analysed.

a) analyses the twinning interface between the PTw and iDTw;

b) proposes a three-elements architecture;

c) analyses the visualization element and its fidelity, which is a key component of the interface among the three-elements architecture;

d) analyses the elements that constitute an iDTw system to understand the unique properties of iDTw;

e) explores the differentiation from cyber physical systems (CPS) or augmented reality (AR), which are similar to existing concepts of iDTw.

— applications of iDTw;

— implementation of iDTw.