Principle-based digital twins: a scoping review

The Construction Innovation Hub and the Centre for Digital Built Britain's National Digital Twin Programme are calling on leaders involved in creating and managing the built environment to build the Gemini Principles into their digital strategies, especially for work on digital twins.The principles will enable a values-based approach to the development of digital twins and pave the way for secure, resilient data sharing, which is at the heart of the National Digital Twin.Published by the Centre for Digital Built Britain in 2018, the Gemini Principles introduce a novel approach to digital twins by setting out generic principles for -rather than specific technological solutions to or outcomes from -the implementation of digital twins.This paper provides an answer to the question of whether principle-based digital twins have been explored before in published literature.Existing applications of digital twins have been motivated in a variety of ways based on their contexts and intended outcomes.These motivations tend to vary by sector and by academic discipline.Whether or not these motivations qualify as principles is debatable.Similarly, digital twins may be intrinsically linked to organisational principles or strategies without this fact being evident in the literature.Therefore, a definitive assessment of how many principle-based digital twins exist would be exceedingly difficult.What is evident from a scoping review of the literature are different levels of strategy and motivation underlying the use of digital twins, from national and regional digital strategies, to organisational strategies, to the motivations driving individual academic or industrial case studies.In this paper, these have been loosely mapped to the Gemini Principles in order to draw some broad conclusions about their frequency in the literature.The most prevalent motivations are simulation, control, efficiency and structural health monitoring, with relatively few papers discussing digital twins in terms of public good, security, sustainability or collaboration.The most notable exception is the literature around smart cities. Due to their complexity and citizen-centric focus, digital twins for smart cities are more often based on principles that parallel the Gemini Principles.Additionally, a small number of maturity frameworks and strategic road maps capture elements of the Gemini Principles and wider work toward a National Digital Twin (NDT).Many of the papers focus on technical aspects of digital twins and also cite remaining technical barriers.However, many of these technical barriers intersect with social and organisational solutions.The gap around principles and service-or citizen-centric digital twins indicates that developing frameworks for principle-based digital twins is a challenge that very few academics or sectors are attempting to address.