Afiqah R. Radzi, Nur Farhana Azmi, Rahimi A. Rahman

Smart cities often integrate multiple Internet of Things (IoT) devices, sensors, and other digital technologies to collect and analyse data from various sources, such as: 

• Traffic,
• Energy usage, 
• Air quality, 
• And waste management.

The data gathered by these tools are then used to improve city services and infrastructure to better meet the needs of its citizens. This article discusses the relationship between smart cities, digital twins, building information modelling (BIM), and construction readiness.

In 2015, the United Nations introduced the Sustainable Development Goals (SDGs). These goals act as a global call to take action to eradicate poverty, safeguard the planet, and ensure that by 2030, all people live in peace and prosperity. Accordingly, some SDGs can be achieved through smart city projects (Figure 1). 

For example, SDG 11 aims to make cities and human settlements more inclusive, safe, resilient, and sustainable. Traffic congestion and pollution can all be reduced, and public safety can be improved by developing smart cities. Smart city development is also related to SDG 7 (Affordable and Clean Energy), SDG 9 (Industry, Innovation, and Infrastructure), and SDG 13 (Climate Action). 

The development of smart cities may include using renewable energy sources, implementing smart grid technologies, and developing more sustainable transportation systems. Smart city development can generally contribute to a wide range of SDGs by utilising technology and innovation to create more sustainable, resilient, and livable communities. Aligning smart city projects with the SDGs can help cities achieve a more thorough and integrated approach to sustainable development that addresses citizens' needs while promoting global sustainability goals.

Digital twin and smart cities

“A digital twin is a virtual representation of a physical asset, process, system, or service used to understand and predict future issues over its life cycle.

The physical twin, the digital model, and the linkage between them are the three basic components of a digital twin. It is possible to predict how a physical system will operate over time and under varying situations by developing the system’s digital twin. When creating digital twins, sensors, data analytics, and machine learning are utilised to gather and analyse data about the replicated physical system. Then, the data is used for developing a virtual model that may simulate and optimise the physical system's performance, identify potential problems or issues, and make informed decisions about improving its performance. Thus, digital twins are a concept rapidly being implemented in various fields and applications to optimise the performance of complex systems and processes.

The performance of different kinds of systems, such as buildings, infrastructure, and even entire cities, is being optimised with the help of digital twins. City planners and administrators may enhance the efficiency and sustainability of city infrastructure and services by developing a digital twin of a city and simulating various scenarios, analysing data in real time, and making informed decisions. A digital twin can provide insights into how the city operates and where changes might be made using real-time data from sensors and other sources. City administrators can benefit greatly from digital twins because of their ability to collect, generate, and analyse data on the environment of the city (Figure 2). For instance, a digital twin of a city's transportation system may be utilised to;

                   ·        investigate traffic patterns,

                   ·        make congestion forecasts,

                   ·        and improve traffic flow.

Furthermore, digital twins can help recognise issues, anticipate future risks, and perform predictive maintenance. By combining IoT and digital twins, energy and maintenance expenditures can be lowered by up to 20%. Gathering real-time information about a facility and comparing it to historical information provides a more accurate estimation of maintenance requirements, hence avoiding downtime and potential failures. It is also possible to simulate and assess various solutions to anticipate problems or even extend the life cycle of a facility. Therefore, digital twins can aid in the development of smarter cities by offering city planners and administrators an effective means for real-time optimisation of infrastructure, services, and resources, enhancing citizens' quality of life.

Building information modelling (BIM) and smart cities

An accurate BIM model is crucial for creating a precise digital twin. BIM is a digital process that involves constructing a 3D model of a building or infrastructure asset and adding precise information about its physical and functional properties. The information from the BIM model can then be used throughout the entire lifecycle of the building or infrastructure asset, from the design and construction phases all the way through the operation and maintenance phases. Information regarding the geometry of the building or infrastructure asset, as well as information regarding the materials, components, and systems that comprise the asset, can be included in BIM models. An accurate BIM model is essential when creating a precise digital twin. A BIM model can assist in ensuring that the digital twin appropriately reflects the behaviour and performance of a building or infrastructure asset by providing a comprehensive digital representation of the physical asset.

The BIM model can create a digital twin of a building or infrastructure asset, allowing for the simulation and optimisation of the asset's behaviour under diverse situations and predicting its performance over time. An accurate BIM model can be especially helpful in the context of smart cities, where digital twins can mimic and optimise the operation of entire city districts, including buildings, transportation systems, energy networks, and other infrastructure assets.

In summary, BIM models and digital twins serve as essential components for developing smart cities because they enable more efficient and effective design, construction, and management of buildings and infrastructure assets.

Construction readiness and smart cities

Construction readiness is defined as the series of activities and procedures that should be completed or substantially completed before construction to productively start and sustain operations. Findings from prior research show that construction-ready projects performed better than construction-not-ready projects in several factors, including cost and schedule.

Construction-ready projects have, on average, 22% schedule reduction, 29% productivity improvement, 20% cost savings, 7% less rework, and 21% less change relative to construction not-ready projects.

 In addition, another study found that in addition to discrepancies between stakeholders, the degree of importance of each readiness factor can vary significantly between different types of construction projects. Therefore, there is a need to ensure adequate construction readiness for construction projects to be efficiently and effectively carried out, creating smarter, sustainable, and resilient cities that meet the needs of citizens while also reducing negative impacts on the environment.

Construction readiness involves ensuring all necessary planning, design, and engineering work has been accomplished and obtaining all relevant permits and approvals from regulatory agencies. To be ready for construction, a project team must have a thorough plan for construction activities, materials procurement, and project management in place, as well as an in-depth understanding of the project's scope, schedule, and budget. Extensive planning, design, engineering effort, and a thorough assessment of potential risks and mitigation measures are critical for construction readiness.

In addition, ensuring that all relevant resources and employees, such as labour, equipment, and materials, are in place and ready to begin work are some factors in ensuring the project is ready for construction. Creating a realistic and achievable construction schedule and ensuring that all essential permits and approvals have been secured from regulatory bodies are several ways to ensure projects are construction ready. Ultimately, establishing construction readiness is crucial to the success of any construction project since it guarantees that all necessary preparation has been accomplished before the start of work, reducing the chance of delays, cost overruns, and other potential issues. Figure 3 presents the relationship between construction readiness, BIM, digital twins, and smart cities.

There are numerous reasons why projects may not be ready to begin construction (Figure 4). For instance, a lack of planning. Construction projects require meticulous planning to ensure all aspects are properly coordinated and managed. Construction may be delayed or jeopardised if planning is weak or incomplete. 

On top of that, design errors are a common reason for construction projects to run behind schedule, especially if the errors are not spotted until the very beginning of the construction. Construction delays might occur when the design contains flaws or errors or when the design is not coordinated with other project components. In addition, several permissions and approvals must be obtained from local authorities and regulatory bodies before construction can begin. Delays in acquiring these permits can cause construction to be delayed. Furthermore, projects need funding to pay for workers, materials, and equipment. Construction may be delayed if funding is not available or is postponed. Finally, contractual issues, such as disagreements over project scope or being late in acquiring necessary approvals, might cause construction to be delayed.

In summary, projects may be delayed owing to difficulties with planning, design, permits and regulatory approvals, funds, and contractual issues. Avoiding these problems requires careful planning and coordination of all project elements, prompt acquisition of all required permissions and approvals, and adequate resolution of financing and contractual issues. Hence, a construction readiness assessment is necessary to ensure the project can start and sustain the operation, resulting in a successful outcome for all parties involved.

Stakeholders must establish specific measures to ensure that projects are ready before commencing construction. For example, completing a construction readiness assessment before starting construction. The assessment may include a review of the design documentation, cost estimates, construction schedule, and other essential project details to guarantee the completeness and accuracy of the project. Additionally, stakeholders must validate the design documents before construction to ensure projects are constructible and fit the project's criteria. A part of this process involves communicating with the design team to fix any problems that have been identified after analysing the drawings, specifications, and other design documents. 

Furthermore, all required permits and approvals from local authorities, including building permits, environmental permits, and other regulatory clearances, must be secured before beginning construction. In addition, efficient contract management can ensure the contractor is ready to begin construction and that all required resources and materials are on hand. Finally, it is important to prepare the site before beginning construction to ensure that it is ready for construction and that any issues have been identified and resolved. Project owners can reduce the risk of premature starts in construction, which can lead to delays, cost overruns, and quality issues, by adopting these measures to assure construction readiness. Project owners may increase the probability of a positive outcome by starting construction only when the project has been fully ready.

Conclusion

A tool is needed to assess the construction readiness of projects, specifically BIM-based building projects. BIM-based building projects are essential for developing smart cities because by leveraging BIM, these building projects enable collaboration, provide accurate information, increase efficiency, enhance sustainability, and improve maintenance. Additionally, completing successful building projects ranging from small-scale residential projects to large-scale commercial or public infrastructure developments can have significant economic and social impacts, creating jobs, stimulating growth, and improving the quality of life for individuals and communities. Hence, a construction readiness assessment tool may help ensure that BIM models are accurate and comprehensive, which is crucial to creating precise digital twins that can be utilised to enhance the performance of the built environment for smart cities. In addition, a construction readiness assessment tool for BIM-based building projects can assist project teams in identifying any issues with the BIM models before construction. This may involve verifying the model's accuracy and completeness, ensuring that all required components and systems are included, and ensuring the model is constructible. Moreover, the tool helps ensure that the BIM model accurately reflects the final design and supports a successful construction project by identifying potential conflicts, checking for accuracy, and optimising construction sequencing. In conclusion, a tool to assess the construction readiness of BIM-based building projects can help guarantee that the BIM models are correct and comprehensive, which in turn helps to produce more accurate digital twins and, ultimately, assists in the successful development of smart cities.

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