## 3 Results and Discussion
### Lean Construction Tools
#### 3.1.2 Validation of Lean Tools in the Building Design Process
Likewise, VSM and LPS are identified as relevant tools in this category. Notably, IPD is mentioned as a standard for applicability in various countries, aiming to standardize certain practices [75]. Although application frequencies vary for other tools, all have been used in building design, validating the 12 Lean tools in the design process described in Section 3.2. To statistically validate the observed differences in familiarity and application levels among the Lean tools, a Friedman test was conducted across four dimensions: general recognition, literature reading, application in the third person, and application in the first person. The results revealed statistically significant differences in all four dimensions (\(p<0.001\)), indicating that not all tools are equally known or applied by the experts. Subsequently, Wilcoxon signed-rank post hoc tests with Bonferroni correction were applied to identify  
Figure 3: Validation of Lean tools applied to design. specific differences between tool pairs. Although global significance was detected, pairwise comparisons did not yield statistically significant results after correction, suggesting that differences are more general than specific. These findings reinforce the uneven adoption of Lean tools in design and highlight the need for targeted dissemination and training efforts depending on the tool. Recommendation Rating of Each Lean Design Tool  
Figure 4 presents a box plot illustrating experts' recommendations on the 12 Lean tools in the building design process, evaluated on a scale from one to seven. The \(Y\)-axis represents this recommendation scale, while the \(X\)-axis lists the names of each tool. This analysis is relevant for identifying the level of acceptance and preference that each tool has in the field of building design, allowing an understanding of which are considered more effective or applicable based on professionals' experience in the area. Interpreting these recommendations provides valuable insights for research, guiding future implementations of Lean tools in design projects. It highlights those that may offer greater benefits or are better supported by the expertise and knowledge of the consulted experts. Figure 4 shows a strong consensus among experts regarding recommending Lean tools in the building design process. Among the highest-rated tools, Agile Design Management (ADM), Building Information Modeling (BIM), Visual Management (VM), and Target Value Design (TVD) stand out due to their low response dispersion, indicating a high level of agreement. ADM, with a standard deviation of 0.7, is positioned as the most recommended tool, followed by BIM and VM, with a standard deviation of 0.8. TVD ranks fourth in consensus, while the Last Planner System (LPS) holds the fifth position, consolidating all these as key tools in building design projects. In contrast, some tools generated greater variability in expert opinions, reflected in a wider dispersion of their ratings. These include Value Stream Mapping (VSM), Linguistic Action Perspective (LAP), Set-Based Design (SBD), and Design Structure Matrix (DSM), whose ratings show greater diversity. This dispersion could be attributed to lower famil  
Figure 4: Box plot illustrating experts’ recommendations on the 12 Lean tools in the building design process, evaluated on a scale from 1 to 7.  
iarity among experts, as shown in Figure 4, where LAP and DSM appear less known or used in the building design field. Additionally, this variability may be related to individual interpretations of their applicability and effectiveness in this context. Finally, although some discrepancies are observed in the recommendation of tools such as LPS, BIM, VM, and ADM, where outlier ratings were identified, these tools--except for LPS--generally maintain a low dispersion in their evaluations. This suggests that, despite some divergent opinions, there is a high overall consensus on their utility and effectiveness.