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Although many of us may be fascinated by the sight of airplanes when we visit an airport, it is important to note that the airport's primary focus is to provide a smooth passenger flow. This involves a complex system of protocols and procedures to facilitate check-in, security screening, boarding, and other essential processes.
While the airplanes themselves may be the stars of the show, the careful orchestration of behind-the-scenes operations truly keeps the airport running smoothly and safely.
An airport is a complex system comprising many facilities and involving many stakeholders that contribute to maintaining passenger flow.
Managing that flow involves collaborating and coordinating multiple elements, making it a highly intricate and multifaceted system. This includes, but is not limited to, the various terminals, gates, check-in counters, baggage handling areas, security checkpoints, and airline personnel working in tandem to ensure a seamless experience for travelers.
An airport digital twin, in essence, is a tool that allows airport management to maintain a smooth passenger flow through the airport while maximizing the use of the available facilities, maintaining a high level of safety, and providing the passenger with a great customer experience.
With the help of a digital twin, airport management can optimize the airport's resources and provide passengers with a smooth journey while maintaining the highest safety standards and delivering exceptional customer service.
Before explaining what an airport digital twin is, we must first understand the concept, and clarify what it is not. The digital twin model was introduced in 2002 as a concept for Product Lifecycle Management (PLM)—it is the information construct of its physical twin. 
The idea of a digital twin completely changes our approach to technology. It is a virtual replica of a process or a physical object like a machine, vehicle, or building, which enables us to simulate and analyze real-time data. This technology has the potential to drastically transform how we create, construct, operate, and maintain physical assets.
The use of digital twin technology has numerous benefits. It speeds up the process of prototyping and testing new designs, while also allowing for quick adjustments to changing circumstances.
By having a thorough comprehension of how a physical asset operates, a digital twin can predict the possible consequences of a situation and identify potential areas for improvement.
Moreover, digital twins enable the remote supervision and management of physical assets, which opens up new prospects for maintenance, operations, and asset management. The incorporation of a digital twin helps to mitigate system complexity by providing more and better information about the real-life physical twin.
As Dr. Michael Grieves, who is credited with the introduction of the concept, indicated in a recent interview, the underlying reason for digital twins is that “information is a replacement for wasting resources.” 
When completing a task, it is essential to use the minimum required physical resources and while information cannot replace physical resources, it can be utilized to reduce waste and achieve faster and cheaper results in accordance with the principles of Lean Thinking.
Digital twin concept breakdown.
© Adapted from multiple sources: , , .
A digital twin must have three components, as shown in the diagram above:
A model: This is the stored representation of the physical twin. Structured information organized through Building Information Management (BIM), Geographic Information Systems (GIS), and Computer-Aided Design (CAD).
Simulation and Predictive Analytics: This is the computational representation of the physical twin. It can be achieve via simulation representing the behavior of the physical twin, and algorithms such as Artificial Intelligence algorithms like machine learning and fuzzy logic.
Synchronization: The application of Operational Technology (OT) and Information Technology (IT) to the collection of data and feedback of information in real-time. Typically displayed on Dashboards from which airport staff can take proactive actions.
If any of these three elements is not present, we do not have a digital twin. This statement acknowledges the relevance of BIM/GIS/CAD, simulation, AI, and OT/IT as relevant tools, but that they do not constitute digital twins on their own.
An airport digital twin is not just one digital replica of the entire airport. Rather, it is a compilation of numerous ones that work together as an integrated, interoperable, and synchronized system. This approach allows for a comprehensive simulation of all aspects and components of the airport, from the terminal buildings and runways to the air traffic control systems and baggage handling processes.
By utilizing this technology, airport operators can gain valuable insights and make data-driven decisions to improve the overall efficiency, safety, and passenger experience of their facility.
Digital Twins can be used for time critical systems like baggage handling, and some airports, for example Hong Kong International Airport, are already using it. Lily Lai, Chief Information Officer, of HKIA Airport Authority says that digital twinning “has enabled the airport to accelerate its understanding of complex systems, explore hypothetical changes, and enable faster and better business decision-making.”
Last summer, Hamad International Airport (HIA) in Qatar also officially launched a digital twin initiative as part of its Smart Airport program. The digital twin provides a real-time view of the gateway through a 3D interface. A powerful analytical engine integrates information from multiple systems to provide intelligent recommendations to optimize operations.
Suhail Kadri, Senior Vice President Technology & Innovation at Hamad International, said at the time: “Hamad International Airport, in conjunction with SITA, is actively shaping the future of the airport industry by being one of the few airports in the world to develop a functioning digital twin and experiment with challenging use cases, ushering in a new era of efficiency.”