## 4 Case Study  
The KBimVdi System, developed based on the algorithm optimized for the BIM environment, was applied and tested to a small-sized design firm in Korea, where BIM projects were being undertaken. The selected firm was considered small in size, with less than 10 employees in the design department, and used BIM tools including Revit, ArchiCad, Midas, and Tekla. Validation tests were conducted on four projects undertaken by this firm with four BIM users each in charge of the projects used for validation. The selected projects were also small to medium in size making them suitable for the scope of this study. Specifically, the structure of selected projects fell within the size requirements of two underground floors and four above ground floors, which is small in size compared to projects typically undertaken by larger architectural design firms. These four projects selected for validation consisted of: a residential new construction building, a dormitory extension, remodeling, \begin{table}
\begin{tabular}{c c c} \hline \hline  & \multicolumn{1}{c}{\(\quad\)KBimVdi Login} & \multicolumn{1}{c}{\(\quad\)BIM Management} \\ \hline  & \multicolumn{1}{c}{\(\quad\)Selection of Software Type} & \multicolumn{1}{c}{Selection of Design Phase} \\ \hline  & \multicolumn{1}{c}{\(\quad\)Selection of Project Size} & \multicolumn{1}{c}{Selection of Type of Work} \\ \hline \hline \end{tabular}
\end{table} 
Table 6: Screen capture of key components of the KBimVDI system. After the validation projects were selected, a detailed analysis of the personal computer environments of the four BIM users was conducted. Then, both their predecessor's desktop (PC) performance and KBimVdi virtual machine's performance were evaluated after establishing VDI resource values via KBimVdi. A considerable difference on specification of PCs was found between the high-performance PC assigned to one BIM user, which had an Intel(r) Core (TM) i7-4710 MQ @2.50 GH CPU, NVIDIA GeForce GTX 750 graphic card, and 16 GB RAM, and a lower-end PC, which had the E7400 CPU, Radeon 4800 Series graphic card, and 4 GB RAM, used by another BIM user. The virtual machine's environment of the VDI, calculated to be compared with PCs of the BIM users, was as follows: CPU, GRID K1 4, 16 GB (4 GB/GPU); 16 GB RAM; and 4 GB RAM leading to lower specifications of the VDI environment compared to the existing desktop environment of the users. Tables 11-14 summarize the specifications of existing PCs occupied and used by the four BIM users and the matching virtual machines recommended. Measurements of both the KBimVdi and the users' existing desktop showed that all the users under the two environments had differences in resources (high and low). However, under the KBimVdi server environment, the difference between the high-performance and lower-performance server was found to be smaller compared to the users' existing desktop environment. This indicates that the VDI system had provided neither too much nor too little support for computing resources and was operated and maintained in a stable way. The test on performance of the BIM design environment showed that both the desktop and the KBimVdi server were capable of running smoothly, and it was found that both servers had used the BIM tool effectively. A test to compare and analyze both the VDI server and the existing desktop was conducted by measuring how much the flexible VDI resource was used with the fixed desktop's performance set at 100%. Among the components of hardware, a test performed on the CPU, which is a key hardware component, showed that BIM User 1 could save resources by 26% compared to the existing desktop, whereas the resource saving could be 29.7% for User 2 (refer to Figure 8). Similarly, User 3 and User 4 could save resources by 16% and 20%, respectively (refer to Figure 9) making the average for savings 22.9%. For User 1 and 2, who had high-performance PCs, the saving effect stood out specifically during the early phase of design at about 35%, which was the highest.