Developing a graph-based algorithm for optimising scheduling and network planning as part of subway construction subject to limited resources

The growing urban development and expanding metropolitan areas emphasise the importance of sustainable, efficient, and environmentally friendly transportation systems that provide convenience and accessibility. In particular, the construction of subways plays a key role in improving accessibility and stimulating economic progress. Given the high complexity and financial costs that such large projects entail, innovative planning methods are needed to reduce risks and use resources efficiently. This study aims to develop an advanced graphbased planning algorithm that would be able to manage resources as efficiently as possible. Methods. The paper presents the results of a comprehensive study of topical publications as regards the improvement of civil engineering processes and integration of the graph theory to enhance the controllability of complex systems, e.g., as part of subway construction. The study focused on the monographic method of analysis that reveals each element of the examined problems, and the use of the reflexive method to comprehend the obtained information and draw substantiated conclusions. The combination of the above methods allowed not only to evaluate, but also to confirm the advantages of the proposed optimisation strategy focused on improving the efficiency and adaptability in construction projects, especially in the construction of subways, taking into account their specificity and real-world requirements. Results. The paper notes the significant role of the graph theory in improving the efficiency of subway construction. The application of this mathematical method allows improving the project management system taking into account the limited resources. The graph theory acts as the key element that brings structure and order to complex processes, as well as ensures rapid adaptation to any changes in the course of the construction activities. The developed algorithm is special in that it contributes to a most efficient resource allocation, reduced downtime and eliminates delays at various stages of a project. Thus, a higher accuracy of planning and the overall economic efficiency of construction activities are achieved. The paper also delves into multiobjective optimisation. This method enables a perfect balance of construction time, budget, and quality, which is important for such large-scale and resource-intensive projects as subway construction. Conclusions. An efficient use of the proposed algorithm will significantly improve the quality of management, reduce the costs and time required for the delivery of construction projects, which makes the method not only relevant, but also vital to their success. That opens up new opportunities for research and application of the above methods in urban planning and deployment of major infrastructures. The paper will be of particular interest to urban planners, civil engineers, process optimisation researchers, as well as project managers responsible for the planning and successful delivery of large-scale civil engineering projects.