## 3 Methodology
### Data Collection  
A variety of methods were used to collect relevant data from the OC project. These data collections can be divided into three different categories:  
1. **Design-related data collection:** More than 30 h of (virtual and in-person) meetings were conducted with the computational designer and other stakeholders. Through these meetings, the research team gained insights into the computational approach to creating different design scenarios and performing computational optimizations for constructability in the OC project. Furthermore, the designer provided access to various design documents, including their BIM in Autodesk Revit format, their parametric model in Rhinoceros format, their computational algorithm in Grasshopper, the delivered shop drawings to the fabricators of the concrete panels, and the relevant electronic communication between the computational designer and other project participants during the computational phase. This close collaboration was a significant driver for this research and led to the inclusion of the computational designer as a co-author of this paper.  
Figure 2: Architectural design concept before the computational design for constructability (**left**) ©Perkins+Will; Constructed facade after the computational design for constructability (**right**) ©BIM TOPiCS Lab.  
2. **Fabrication-related data collection (off-site):** The research team visited the fabrication site two times and interviewed the fabricators to understand the constructability issues, the impact of computational design and optimization from their perspective, and the information exchange between designers, fabricators, and installers. Furthermore, the research team obtained access to the modified shop drawings of the concrete panels developed by the fabricators and the related calculations. The most noticeable change in the design was the addition of panel embeds by the fabricator. Panel embeds are responsible for the connection of the panels to the main structure. The panel embeds are discussed in more detail in the next section. It should be noted that the fabricators did not have the capability to use BIM and had to work with 2D drawings generated from BIM by the architect.
3. **Installation-related data collection (on-site):** The research team conducted weekly site visits over a span of six months. During these visits, the research team interviewed workers with different roles and videotaped and photographed various installation cases and issues. These included ongoing activities on the ground, i.e., at the truck that transports the panels, as well as the actual panel installation process on the building facade.  
It should be noted that as part of the data-collection efforts, 20 semi-structured interviews, each lasting about an hour, were conducted individually or in groups. The participants included practitioners from the manufacturing company, trades responsible for facade panel installation, project managers, and the design team, including the computational designer. In the interviews with the trades and manufacturers, the primary focus was on the constructability issues identified and the knowledge provided to the design team throughout the project. This is while the interviews with the design team, particularly the computational designer, were expanded to explore how the received expert knowledge was integrated into the computational design process.  
Additionally, the research team had access to two time-lapse cameras with 5-min intervals installed at the project site, enabling the research team to monitor the installation progress of the concrete panels at any time.