## 3 Analysis and Results
### Quantitative Analysis
#### 3.1.2 Comparative Analysis of Working Days and Worker Numbers  
To further understand the impact of BIM applications on labor quantity and construction time, Table 6 compares the changes in the number of workers and working days between scenarios with and without the participation of professional BIM consulting. These data are collected from measurements conducted separately by the construction units and BIM consulting units of the two projects. For readability, unchanged data are represented by \"--\".  
The results indicate that, in terms of the number of workers, the scenarios of addressing collision issues, preventing delays, and rework costs due to design changes and errors did not result in changes, regardless of the participation of professional BIM consulting companies. However, with the involvement of BIM consulting, the number of workers increased by one person and three persons at the two construction sites (from two to three persons and from two to five persons, respectively). Although the number of construction  
\begin{table}
\begin{tabular}{c c c c c c c c c} \hline \hline \multirow{3}{*}{**Code**} & \multicolumn{4}{c}{**Non-BIM**} & \multicolumn{4}{c}{**BIM**} \\ \cline{2-10}  & \multicolumn{2}{c}{**Project 1**} & \multicolumn{2}{c}{**Project 2**} & \multicolumn{2}{c}{**Project 1**} & \multicolumn{2}{c}{**Project 2**} \\ \cline{2-10}  & **Worker** & **Working** & **Worker** & **Working** & **Worker** & **Working** & **Worker** & **Working** \\  & **Numbers** & **Days** & **Numbers** & **Days** & **Numbers** & **Days** & **Numbers** & **Days** \\ \hline e & 2 & 120 & 2 & 100 & 3 & 24 & 5 & 18 \\ f & 17 & 48 & 9 & 46 & — & — & — & — \\ g & 12 & 29 & 14 & 61 & — & — & — & — \\ Total & 31 & 197 & 25 & 207 & 32 & 101 & 28 & 125 \\ \hline Average of & & & & & & & & \\ total workers & & & & & & & & \\ \hline Average of working days & & 202 days & & 113 days & & & \\ \hline \hline \end{tabular} Note: Worker numbers are calculated per working day.  
\end{table}
Table 6: Difference in worker numbers and working days between using BIM and non-BIM.  
\begin{table}
\begin{tabular}{c c c c} \hline \hline
**Title** & **Division** & **Cost** & **Percentage (\%)** \\ \hline \multirow{2}{*}{Project 1} & Basic Cost & 145,126 & 214.0 \\  & Investment Cost & 67,828 & 183.3 \\ Project 2 & Basic Cost & 143,920 & 197.6 \\  & Investment Cost & 77,853 & 183.3 \\ Average total cost & Basic Cost & 143,920 & 197.6 \\  & Investment Cost & 72,840 & 197.6 \\ \hline \hline \end{tabular}
\end{table}
Table 5: Comparative analysis of investment cost percentage.  
personnel increased when compared to self-construction by the construction units, the total working days at the two sites reduced from 120 days to 24 days and from 100 days to 18 days, respectively.  
Comparing the data from the two construction sites, the total number of workers slightly increased when BIM consulting was involved, from 31 to 32 persons for Project 1, and from 25 to 28 persons for Project 2. The average total number of workers also slightly increased from 28 to 30 persons. However, the total working days at the construction site of Project 1 rapidly decreased by 96 days, from 197 days to 101 days, and the construction site of Project 2 also reduced by 82 days, from 207 days to 125 days. The average total days decreased significantly from 202 days to 113 days, a reduction of 89 days. This indicates that the involvement of BIM consulting companies, while increasing the average number of workers, effectively shortens the working time, thereby reducing the overall investment cost of construction projects.