Page 18 - Redefining smart city platforms: Setting the stage for Minimal Interoperability Mechanisms - A U4SSC deliverable on city platforms

The need for cities to manage unified data repositories that allow inter-domain solutions to be
offered where required is clear. The concept of data spaces seems to be a promising approach to
enable cities to address the need for informational or semantic interoperability.

2.6 Local digital twins

The development of digital twins can play a pivotal role in the establishment of smart and sustainable
cities by providing accurate, real-time, digital representations of the city to help with city planning
and management.

In general, a digital twin can be considered as “a digital representation of a physical asset or the
service delivered by it, used to make decisions that will affect the physical asset. Any changes to
the physical assets will be reflected in the digital twin.” 12

The digital twin provides a means to simulate, predict outcomes, forecast behaviour, and possibly
control the real-world entity where applicable. Digital twin models can help organize data and pull
it into interoperable formats so that it can be used to optimize infrastructure use. Digital twins can
also share these data, with defined levels of access, to inform better decisions about which future
infrastructure to build and how to manage current and future infrastructure.

The digital twin concept has its origins in mechanical engineering and the use of digital models
to represent a component or a machine in such a way that it does not simply look the same for
visualization, but also behaves in the same way. As the model framework is spatially and temporally
accurate, and also has dynamic properties that enable it to deal with the things that change for a
system during operation, as well as changes that occur because of the effect of its environment,
the digital twin can be used not only for visualization but also for interaction. In this way, it can
enable simulation and prediction of what would happen to the physical asset based on the digital
behaviour.

This has been brought across to support modelling at urban scales relating to urban environments.

The “Living-in EU” initiative defines local digital twins as: “a virtual representation of a city’s physical
assets, using data, data analytics and machine learning to help simulation models that can be
updated and changed (real-time) as their physical equivalents change” (European Commission,
n.d). 13

A local digital twin could be a comparatively simple model used, for instance, to identify the impact
on traffic flows in the city or help decide whether a major development site in the city would best
be used for housing, retail, or offices. Or it could be a comprehensive and detailed model of the
city, allowing the drilling down from an overall view of the city to the detail of individual pieces of
street furniture. It may be focused on the physical assets and infrastructure of the city, or it may also
include detailed information about the profiles and behaviours of the people and organizations
that use those physical assets and infrastructures.

8 Redefining smart city platforms: Setting the stage for Minimal Interoperability Mechanisms