## 3 Results
### Phase I: Defining PC On-site Assembly Optimization Principles via BIM-GA Hybrid System
#### 3.2.2 Application of Genetic Algorithm
\begin{table}
\begin{tabular}{c c c} \hline \hline
**Type** & **No.** & **Evaluation** \\ \hline \multirow{6}{*}{Advantage} & \multirow{3}{*}{2} & In digitized construction sites, such management approaches are essential, and they are expected to aid in systematic on-site management. \\ \cline{3-3}  & & When undertaking construction projects with PC structures in urban or similar areas, the scarcity of space for PC component storage necessitates a thorough assembly and delivery plan. \\ \cline{3-3}  & & Considering this, the study is anticipated to contribute by identifying the optimal assembly sequence to address these challenges. \\ \cline{3-3}  & & A system that verifies the anticipated assembly sequence through simulation proves highly beneficial for on-site management. \\ \hline \multirow{6}{*}{Limitation} & \multirow{3}{*}{1} & Consideration of additional variables occurring on site is essential. Developing an assembly plan that comprehensively integrates factors such as weather, manpower, and equipment would contribute to a more systematic assembly plan. \\ \cline{3-3}  & & As construction sites continue to heavily depend on manpower, a successful application of this methodology requires a comprehensive management system, encompassing not only the construction phase but also information from all preceding stages, including transportation and delivery, to enhance feasibility. \\ \cline{1-1} \cline{3-3}  & & As construction sites continue to heavily depend on manpower, a successful application of this methodology requires a comprehensive management system, encompassing not only the construction phase but also information from all preceding stages, including transportation and delivery, to enhance feasibility. \\ \hline \hline \end{tabular}
\end{table} 
Table 5: Evaluation of research. (Source: own elaboration). shifting from subjective reliance on the experience and judgment of on-site managers to a computer algorithmic environment for assembly sequence derivation. To achieve this, factors to be considered during on-site assembly planning and execution such as task complexity, adjacency of the work radius, and feasibility of component installation were objectively evaluated and scored to assess the assembly sequence of the components. A Genetic Algorithm was utilized to generate assembly plan alternatives, minimize constraint violations, and enhance the workflow. The validation process involved in-depth interviews with PC site managers, considering the characteristics of the site that involved additional information related to labor, equipment, and the ability of managers to incorporate changes in on-site conditions. Although suggestions were made for additional functionalities, the basic operational principles and flow of the research results were well reviewed, emphasizing the need for such research in the context of digitizing the construction industry. This study aims to shift from subjective to systematic on-site management using computer algorithms, thereby contributing to enhanced construction site productivity. Moreover, it identifies direct assembly-phase factors at PC construction sites and seeks to define the assembly-phase mechanism. The study operated under three defined constraints, prioritizing the assembly in the sequence of the column-beam-slab, starting with the closest component. However, it acknowledges a limitation owing to the oversight of component connection relationships, necessitating active user intervention to ensure structural stability. Therefore, future research should include the interconnection relationships among the components to generate more rational assembly plans. This study, in summary, establishes a systematic approach to OSC-based construction assembly sequences, providing a foundation for future research. It is noteworthy that the integration of time-cost analysis into the proposed approach can provide a more comprehensive perspective on both the feasibility and efficiency of a construction practice.