## 5 Economic Analysis  
This section discusses the overall economic feasibility evaluated based on the module design effort, additional material input, and fabrication effort analyzed in the previous section. The economic feasibility was evaluated using the following:  
\[\text{Structural Framing Cost}=\frac{\text{Design Cost}}{\text{m}^{3}}+\frac{ \text{Material Cost}}{\text{m}^{3}}+\frac{\text{Fabrication Cost}}{\text{m}^{3}}, \tag{1}\]  
where  
\[\text{Design Cost}=\text{Engineering Input (person-day)}\times\text{Labor Cost (USD per day)};\]  
Material Cost = System Channel Input (meter) \(\times\) Unit Cost (USD per day);  
Fabrication Cost = Fabrication Effort Labor Input (person-day) \(\times\) Labor Cost (USD per day). Because the size of PMR is affected by length, width, and height, the basic unit of economic analysis is area (cubic meters). Structural framing cost is the sum of the design cost (person-day input for design phase), material cost (system-channel input for manufacturing), and fabrication cost (person-day input for manufacturing phase) per cubic meter, as analyzed in Section 4. The cost of BIM engineers, the cost of the system channel, and the labor cost of system channel assembly engineers were calculated using Korean price information (www.kpi.or.kr, accessed on 11 June 2022) and the input per cubic meter discussed in Section 3, and the total cost per cubic meter was calculated. The calculated results are tabulated in Table 2. The numbers in brackets corresponding to the total design, material, and fabrication costs represent the ratio of each cost to the total structural framing cost. \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline
**Phase** & & **Type A** & **Type B** & **Type C** & **Type D** & **Type E** \\ \hline Design Cost & Engineering Input & & & & & \\ (per cubic meter) & (person-day) & & & & & \\ Labor Cost & 198.57 & 198.57 & 198.57 & 198.57 & 198.57 & 198.57 \\  & Total Design Cost & 71.49 & 73.47 & 71.49 & 83.40 & 65.53 \\  & (USD) & (29.61\%) & (37.07\%) & (25.62\%) & (25.45\%) & (38.67\%) \\ Material Cost & System Channel Input & & & & & \\ (per cubic meter) & (meter) & 6.75 & 4.13 & 4.55 & 6.61 & 4.05 \\  & Unit Cost & & & & & \\  & (USD per meter) & 15.0 & 15.0 & 15.0 & 15.0 & 15.0 \\  & Total Material Cost & 101.25 & 61.95 & 68.25 & 99.15 & 60.75 \\  & (USD) & (41.94\%) & (31.26\%) & (24.46\%) & (30.25\%) & (35.85\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 2: Results of economic analysis. The most economical structural framing was Type E. Type E showed the most economical values in all aspects of design, material, and fabrication costs. Initially, it was predicted that there would be inefficient parts in the design and the fabrication stages; however, the two stages in the case study also showed the lowest cost input. The second-best economical framing was Type B. Type B, with which economic feasibility was pursued by expanding the supporting interval, generally required low design, material, and fabrication costs. Adjusting the supporting interval within a range that ensures the safety of the PMR module may be one method to produce economic structural framing. The third best economical structural framing was Type A. Type A was found to be the most disadvantageous in terms of material cost; however, its design and fabrication costs were relatively low. The ratio of material cost to total cost was 41.94%, which was the highest. If the material cost in the region where PMR is applied is lower than in other regions, a higher economic feasibility of Type A may be achieved. The fourth best economical structural framing was Type C. The design and material costs required for Type C frames were relatively low; however, the fabrication cost was high. The ratio of fabrication cost to total cost was 49.92%, the highest among all types. If automated facilities that can increase labor productivity in the fabrication stage are introduced, the economic feasibility can be improved.