Chapter 5: Case studies: City-scale digital twins

The concept of a digital twin is not new. Michael Grieves (2014) introduced the term ‘Digital Twin’ almost two decades ago in 2002 in product design. Batty (2018) reflects that since the inception of digital twins, the concept has expanded to encompass a variety of digital simulation models that run alongside real-life processes of social, economic and physical systems. This evolution of definitions parallels the maturation of technology, such as artificial intelligence and machine learning applied to cities (ARUP, 2019; CDBB, 2018; IBM, 2021). Beyond variations in definitions, there are also significant differences relating to how the integrated modelling approach is set up and the practice of using digital twins. Siemens (2020, p. 5) describes current digital twins as a