This study aims to analyze the problem of schedule discrepancy between the schedule prepared in the basic design stage and the schedule applied during actual construction in turnkey projects, which are one of the main ordering methods for large-scale ...
This study aims to analyze the problem of schedule discrepancy between the schedule prepared in the basic design stage and the schedule applied during actual construction in turnkey projects, which are one of the main ordering methods for large-scale domestic construction projects, and to derive the cause and improvement measures for this. The basic design schedule is a document for bidding and evaluation, and is often prepared optimistically according to the requirements of the ordering party and the construction company’s plan. This causes a discrepancy with the actual construction schedule, which leads to problems such as schedule delays, quality degradation, and legal disputes. This study compared and analyzed the basic design schedule and the actual construction schedule focusing on two actual turnkey project cases (the construction of the Hwado-Yangpyeong section of the Seoul Metropolitan Area’s Second Ring Expressway and the Busan Eco Delta City Phase 2 Section 4 construction project) to identify the cause of the discrepancy. The analysis results showed that external factors such as soft ground treatment, equipment and material supply, design changes, and permit delays were the main causes of the schedule discrepancy. In addition, the practice of underestimating the schedule at the design stage and establishing plans centered on evaluation purposes was also analyzed as the main cause. Accordingly, this study pointed out the limitations of the existing air estimation method and proposed improvement measures such as the introduction of a data-based air estimation technique, the use of a real-time process monitoring system (BIM, IoT, etc.), and the establishment of a cooperative air adjustment process between the ordering party and the construction company. The results of this study are expected to contribute to improving the reliability of air estimation and process management of turnkey projects.