# Analyzing the Economic Performance of a TLS-Based Structural Safety Diagnosis Process
## 3 Results
### ROI Evaluation  
#### 3.5.1 Comparing Project-Level and Company-Level ROI  
The project-level ROI for the three cases was calculated using the following Equation (15):  
\[ROI_{project}=\left(\frac{Service\;Fee(b)-Total\;cost(a)}{Investment}\right)\times 1 00(\%) \tag{15}\]  
where _total cost (a)_ refers to the TLS-based inspection cost from Table 7, _service fee (b)_ is the actual contract fee received for each project, (\(b-a\)) is the revenue, and investment is the initial equipment purchase cost (KRW 120 million).  
Summarizing the project-level ROI analysis for the three case projects, Project B exhibited significant investment viability, with an ROI of 135.88%, as the revenue generated from adopting the TLS-based 3D scanning reverse modeling approach substantially exceeded the initial investment. In contrast, Project A yielded a ROI of approximately 13.81%, and Project C yielded about 12.12%, indicating that these two projects individually would require relatively longer periods to recover the initial investment. This suggests that ROI can vary significantly depending on project-specific characteristics, such as facility size and the extent of damage. Consequently, making decisions on equipment purchases based solely on a single project's ROI may lead to an under- or overestimation of investment effectiveness.  
The company-level ROI for the three cases was calculated using the following Equation (16):  
\[ROI_{company}=\left(\frac{Total\;Service\;Fee-Total\;cost}{Investment}\right) \times 100(\%) \tag{16}\]  
As a result of implementing all three projects (A, B, and C), the cumulative profit was about KRW 194.17 million, and the overall ROI reached 161.80% compared to the initial investment of KRW 120 million. This demonstrates that by continuously employing TLS-based 3D scanning reverse modeling across multiple projects, companies can not only fully recover their initial investment but also generate additional economic benefits.  
Detailed results of the project-level and company-level ROI analyses are provided in Table 8.  
\begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Classification**} & \multicolumn{2}{c}{**Project A**} & \multicolumn{2}{c}{**Project B**} & \multicolumn{2}{c}{**Project C**} \\ \cline{2-7}  & **As-Is** & **To-Be** & **As-Is** & **To-Be** & **As-Is** & **To-Be** \\ \hline Investigation period required & 40 & 14 & 80 & 55 & 154 & 66 \\ \(T\)C & 3,127,437 & 959,485 & 7,640,877 & 2,217,135 & 6,208,213 & 1,597,864 \\ \(T\)C & 125,097,493 & 13,432,793 & 611,270,187 & 121,942,416 & 956,064,776 & 105,459,050 \\ \hline \hline \end{tabular}
\end{table}
Table 7: Comparison of total cost savings of visual inspection and TLS-based inspection.  
Considering the project-level ROI outcomes, it is difficult to conclusively state that introducing digital technologies uniformly guarantees cost-saving effects across all projects, as ROI values can vary greatly depending on individual project conditions and complexity. Although individual projects, such as Project A and Project C, showed relatively lower ROI, larger-scale projects, such as Project B, could yield substantial results sufficient to recover initial investments. However, since construction and maintenance companies typically perform multiple consecutive projects, it is more rational to evaluate cumulative return on investment from a long-term perspective. If a company makes an initial investment in digital equipment and continually utilizes it across multiple projects, judging investment value solely based on the profitability of individual projects may not provide an accurate assessment. Ultimately, from a corporate perspective, investment in digital technology is economically more meaningful when considered in the context of executing multiple consecutive projects.