## 2 Literature Review
### Object-Oriented Information Classification System  
Studies focused on constructing an effective construction information classification system continue to be conducted separately from international standardization efforts. However, all classification systems are designed for the integrated management of substantial construction information, surpassing a simple arrangement of construction data [32; 33]. Although the developed classification systems are designed to conform to existing systems and enhance usability through careful analyses of requirements, design and construction work remain disconnected. Therefore, an information classification system that is widely used throughout construction projects is necessary. Some cite the lack of publicity and voluntary participation as reasons for low utilization in the early stages [34]. Nevertheless, the fundamental cause lies in the lack of integrated development for construction information classification systems. [PERSON] et al. [35] proposed an integrated approach, combining the cost breakdown structure and work breakdown structure (WBS) to facilitate budget management and quality control in construction projects. Their method involved breaking down project information into smaller cost-calculating scales and defining unit tasks, allowing its integration with BIM. This integration proved significant as it enabled the representation of construction information in a visual format, centered around the subdivision of information units based on construction costs. However, a challenge arises when directly linking construction cost units to tasks, making it difficult to handle information processing in scenarios involving changes in the project scope or construction methods during the construction phase. Reevaluating and reestablishing the construction information classification system is necessary to overcome this challenge and enable effective information processing, particularly concerning the interconnection of various stakeholders during construction. Research has been conducted from various perspectives on using BIM to digitize the construction industry. Specifically, in the context of architectural structures, studies focusing on the concepts and structure of object classification systems within BIM revealed that shape information for defined components could be systematically managed. This was achieved through the integration of the object breakdown structure, WBS, and project numbering system, as demonstrated in the construction of timber structures [36]. This approach is particularly suitable for buildings with independent spaces for completed  
Figure 2: Rate of infrastructure-related factors: (**a**) OmniClass, and (**b**) UniClass. objects. Developing specialized software to implement this approach can further enhance its effectiveness. Research on the requirements of information classification systems based on BIM information frameworks in infrastructure construction in South Korea yielded two key findings. First, it is necessary to implement three-dimensional (3D) integrated information, preferably linked to existing classification systems. Second, a comprehensive perspective calls for an integrated standards system rather than fragmented standards tailored to individual purposes [37]. Revising the construction information classification system is necessary to effectively utilize BIM, as it allows for the connection between BIM objects and items within the construction information classification system. Additionally, it should incorporate geometric and attribute information, representing it in 3D models, and enable the linking of attribute information to define individual objects [38]. Research was conducted to expand the model breakdown structure under the component classification system of the construction information classification system, which is based on the WBS used in road construction projects in South Korea.