Analyzing the Economic Performance of a TLS-Based Structural Safety Diagnosis Process

In a construction industry characterized by rapid change and increasing complexity, traditional labor-intensive methods of structural safety inspection suffer from numerous limitations, including low productivity, extended project duration, and high costs. Accuracy and speed are particularly vital for safety diagnosis in older structures, fire-damaged buildings, and large-scale facilities, yet conventional methods heavily rely on human expertise, leading to variability and potential unreliability of results. This study quantitatively assessed the productivity improvements and economic benefits of integrating terrestrial laser scanning (TLS) and building information modeling (BIM) into the structural safety assessment process. Both the conventional visual inspection and the TLS-based approach were treated as production systems, and queueing theory was employed to analyze waiting times, service rates, and costs. The analysis of three real-world projects revealed that the TLS-based 3D scanning reverse modeling method reduces total project costs—including survey duration, labor input, as well as service and waiting costs—by about 80–89% compared to the visual inspection method. Additionally, the return on investment (ROI) at the project level varies from approximately 12% to 136%, and when applied to multiple projects at the company level, the overall ROI reaches about 162%, demonstrating the long-term economic benefits of adopting digital technology. These findings suggest that TLS-3D scanning reverse modeling in the construction industry has substantial potential in terms of productivity gains and economic impact.