## 3 Analysis and Results  
### Quantitative Analysis  
#### 3.1.1 Comparative Analysis of Investment Cost  
Although questions involving 16 areas were designed for quantitative research when the researchers developed the quantitative research template. However, in analyzing the results, it was found that there were some data virtually unchanged with or without the involvement of a professional BIM consultancy (e.g., code a-d), or had very little impact (e.g., code k-p). In addition, because railway engineering construction is a large and complex project, this process involves a very complicated amount of work; in order to simplify the calculation, we assume that all other conditions are fixed situation, selected the three aspects of the greatest impact on the project investment to measure the comparison (e-g). The cost-effectiveness of BIM in the construction phase primarily manifests in labor costs and construction duration. With the intervention of BIM information, it becomes possible to proactively prevent common occurrences in the construction process, such as clashes, design inconsistencies, or other issues leading to design changes. This proactive approach helps reduce construction duration and lower costs. However, it is crucial to note that rework caused by issues like substandard construction quality is something BIM cannot entirely prevent. To conduct a comprehensive cross-sectional analysis of the impact on cost-effectiveness between the involvement of professional BIM consulting services and the use of BIM by construction companies themselves, the quantitative survey focuses \begin{table}
\begin{tabular}{c c} \hline \hline
**Area of Questions** & **Calculation Formula** & **Code** \\ \hline Cost of Building & a \\ Collaborative Environment & & b \\ \hline Cost of Initial Clash Checks & c \\ \hline Cost of Shop Drawing Information Work & c \\ \hline Cost of Coordinating and Resolving & & d \\ Other Issues & Average Labor Cost per Rank \(\times\) Number of Workers \(\times\) Working & e \\ \hline Labor Costs & days + Other Expenses 1 & e \\ \hline Costs of Resolving Clashes and & & f \\ Preventing Delays & & f \\ \hline Rework Costs Incurred due to Design & & g \\ Changes and Errors & & \\ \hline Risks Costs Arising from Design Errors & h \\ \hline Costs of Rebuilding after Rework & Average labor cost per rank \(\times\) Number of workers \(\times\) Working days & i \\  & + Material cost + Other expenses & \\ \hline Costs of Preventive Measures for Rework & Average labor cost per rank \(\times\) Number of workers \(\times\) Working days & j \\  & + Other expenses + Service fee & \\ \hline Costs of BIM-Related Support & Average labor cost per BIM department \(\times\) Total number & k \\ Department Involvement & of employees & k \\ \hline Software and Hardware Procurement & BIM software acquisition cost + BIM hardware acquisition cost & 1 \\ \hline Software and Hardware Upgrades & BIM software maintenance cost + BIM hardware maintenance cost & m \\ and Maintenance & & \\ \hline Costs of Quantity and & & \\ Drawing Preparation & Average labor cost per rank \(\times\) Number of workers \(\times\) Working days & n \\  & + Other expenses & o \\ \hline Operational Costs in Case of Data Loss & & \\ \hline Employee Skill Development and & & \\ BIM Training & Training cost \(\times\) Number of training sessions & p \\ \hline \hline \end{tabular}  
* Other expenses: According to the state regulations should be paid in the project construction investment and included in the cost. Such as management fees, subsidies, transport costs, taxes, etc.  
\end{table} 
Table 3: Quantitative measurement calculation formulae. on factors that significantly affect economic benefits under professional BIM consulting involvement. Factors with relatively minor impacts, such as BIM training costs and BIM investment costs, are excluded from the analysis.