When is a simulation a digital twin? A systematic literature review

This paper presents a systematic literature review to analyze the connection between the capabilities of Digital Twin (DT) and simulation; it also reviews industrial applications of DT and its different definitions. After a systematic search of several databases and a careful selection based on established criteria, 120 journal academic publications regarding practical implementations of DT were selected and classified according to the capabilities of DT and/or simulation that they implemented. Based on the results of the SLR classification and analysis, the challenges in this area that are preventing the widespread adoption of a fully capable DT are presented. This work also identifies the current limitations and reasons behind some misconception of DT. There is still a disconnection between the DT concepts and applications, as people continue to construct DTs that are basically simulation models. Furthermore, those that build a DT only make use of a portion of its capabilities.