## 2 Research Background
### Constructability Knowledge  
In this discussion, it is necessary to clearly distinguish between the terms \"data\", \"information\", and \"knowledge\". **Data** is defined as \"symbols\" or \"signs\" representing the characteristics of objects, events, and their environment [27]. In essence, data represents an unstructured set of symbols stemming from observations [28]. **Information** is useful in answering questions that begin with words like who, what, when, and how many [27; 29]. Additionally, information can be considered as structured data useful for analyzing and resolving problems [28]. **Knowledge** is obtained by experts based on their experience, values, and contextual information [28; 30]. Knowledge is also known as \"know-how\" [27], \"information about information\" [28], or \"a fluid mix of framed experience, values, contextual information, and expert insight\" [30]. These definitions of data, information, and knowledge are foundational for understanding how constructability knowledge can be effectively utilized in the design process. In the context of construction, data and information provide the basis for generating actionable knowledge, shaped by experts' experience and contextual understanding. In other words, constructability knowledge encompasses experts' experience on constructability, which is critical for addressing the challenges of designing and building complex prefabricated building components and executing their associated processes. Processes related to prefabricated building components are often categorized into manufacturing and assembly, with the associated design activities classified as design for manufacturing and assembly (DfMA) [31]. Manufacturing includes all off-site activities involved in constructing or building a component, while assembly refers to all on-site activities required to erect or install the component. However, a third set of activities is occasionally incorporated to these processes, covering the transportation and supply chain of prefabricated building components [32; 33], which can become critical when approaching just-in-time deliveries [34]. Therefore, discussing the constructability of a prefabricated building component involves investigating whether the component is manufacturable, transportable, and installable under the given design conditions. As mentioned earlier, when conducting comprehensive research, constructability knowledge for prefabricated building components can be analyzed using a two-dimensional framework. One dimension focuses on constructability knowledge regarding individual components. For example, such knowledge is essential to determine whether the anticipated geometry (shape and size) of a prefabricated component is feasible for manufacturing, transportation, and installation in an effective manner. Examples in this regard include the extraordinary geometries implemented in the Eight Spruce Street project in New York [35], the Galaxy SOHO in Beijing [36], and the Palazzo Italia in Milan [37]. Additionally, on this dimension, constructability knowledge is crucial for assessing whether the semantic (non-geometric) attributes of individual prefabricated components are reasonably assumed. For instance, the authors in [17; 20] discuss knowledge related to materials, the authors in [15] focus on associated costs, and the authors in [17; 38] address the sustainability attributes of prefabricated components. The second dimension of constructability knowledge pertains to the role that prefabricated building components play and the building system they belong to, which subsequently determines the field of expertise required for the constructability review. For example, the authors in [19; 39] provide insights into the constructability of manufacturing and assembly processes for mechanical components, while the authors in [20; 31; 40] focus on structural expertise, and the authors in [35; 36; 37] emphasize the architectural domain. It is also noteworthy that in this dimension, the required expert knowledge often spans multiple fields.