## 3 Results and Discussion
### Lean Construction Tools
#### 3.1.2 Validation of Lean Tools in the Building Design Process  
Validation of the Proposed Lean Tools in the Building Design Process  
Figure 3 illustrates the frequency of affirmative responses from experts regarding using or recommending Lean tools in the building design process. The \(x\)-axis presents the Lean tools identified in Section 3.2, corresponding to Lean Design, while the \(y\)-axis indicates \begin{table}
\begin{tabular}{c c c} \hline \hline
**Tool** & **Description** & **Applied Case** \\ \hline Linguistic Action & \begin{tabular}{c} This approach implies that conversations not only precede \\ action but are actions themselves due to the commitments that \\ arise. Conversations for action involve four fundamental speech \\ acts: (1) request or offer, (2) promise or acceptance, \\ (3) declaration of completion, and (4) declaration of satisfaction. \\ \end{tabular} & DS * [69] \\ \hline Visual Management (VM) & \begin{tabular}{c} Visual management refers to a set of practices that support \\ communication through the use of various visual elements. \\ \end{tabular} & ED * [70] ID, [71] \\ \hline Integrated Project & \begin{tabular}{c} It is a construction project execution method where key parties \\ unite under a single agreement. This promotes continuous \\ collaboration, reduces waste, improves efficiency, fosters team \\ respect, and enhances project outcomes, including the \\ benefits obtained. \\ \end{tabular} & HBD [61] \\ \hline Value Stream & \
\begin{tabular}{c} It is a highly effective tool for optimizing process flow and \\ reducing waste. Value Stream Mapping is an approach where a \\ team maps the value stream in repetitive processes, leading \\ team members to analyze where value is added and where \\ it is not. \\ \end{tabular} & BD [62; 72], HD [73] \\ \hline Integrated Concurrent &
\begin{tabular}{c} It involves collaboration among various actors, such as the \\ design team, specialized engineers, and consultants. This \\ process consists of three elements: performance metrics, BIM + \\ simulation, and process design. This problem-solving technique \\ accelerates solutions by considering multiple perspectives. \\ Design reviews occur in a room where stakeholders discuss \\ design aspects on large screens to speed up the process. \\ \end{tabular} & BD [62] \\ \hline \hline \end{tabular}
\end{table} 
Table 5: _Cont._the frequency of affirmative responses expressed as a percentage. Each tool is represented by four bars that reflect different levels of familiarity and application: general knowledge, reading, second-person application, and first-person application. This structure provides a comparative view of experts' level of adoption and practical experience with each tool in the context of building design. Figure 3 reveals various trends regarding the level of knowledge and application of Lean tools in the building design process. In terms of general recognition, tools such as BIM, LPS, VSM, IPD, CBA, and TVD are known by 100% of respondents, which may be attributed to their long-standing presence and the support of numerous studies in the construction field. Additionally, tools such as SBD, LAP, ADM, and DSM show a lower level of familiarity, likely due to their recent introduction or the complexity of their use. Regarding theoretical familiarity, IPD, CBA, TVD, and SBD are the most frequently read about, with 75% of respondents reporting having studied them in depth. In contrast, ADM, DSM, and LAP have a lower reading frequency. Concerning second-person practical experience, respondents demonstrate knowledge of applications for all tools, with BIM, VM, LPS, and TVD standing out with frequencies above 50%. This indicates that the respondents know cases where these tools have been implemented in building design projects, even if they have not participated directly. Regarding first-person application, BIM stands out as the most used tool, with 63% of respondents reporting direct experience in its application within building design.