## 3 Results and Discussion
### Lean Construction Tools
#### 3.1.1.1. Lean Tools Applied to Design  
Table 5 presents a set of 12 Lean Construction tools that have been used or recommended for application in the design phase, according to the literature review of 26 documents. The tools marked with an asterisk (*) indicate those whose implementation is suggested at this stage. A general description of each tool from the design perspective is provided, along with various cases in which they have been applied or their application has been proposed. \begin{table}
\begin{tabular}{c c c} \hline
**Tool** & **Description** & **Refs.** \\ \hline Big Room & A project approach streamlining communication, & \\  & improving decision-making, and reducing silos. & [53] \\ \hline Total Productive Maintenance & A maintenance tool focusing on proactive and preventive & [40; 41] \\  & equipment care. & \\ \hline Ishikawa Diagram & A tool for identifying and analyzing the root cause of & [54; 55; 56] \\  & a problem. & \\ \hline \end{tabular}
\end{table} 
Table 4: _Cont._ \begin{table}
\begin{tabular}{c c c} \hline
**Tool** & **Description** & **Applied Case** \\ \hline  & It is an approach that considers Architecture, Engineering, and & \\  & Construction as a complex system with definition, design, and & BD * [57; 58; 59], \\  & construction phases. This approach reverses conventional & \\  & design practices by making costs guide the design instead of & \\  & design determining the costs. & \\ \hline  & Designers generate design solutions that incorporate multiple & \\  & criteria, considering the schedule and budget. These solutions & \\  & are collaboratively improved until a satisfactory resolution is & \\  & achieved, while progressively adapting to time and cost constraints. & \\ \hline  & & It is a proven and effective decision-making method that & \\  & & involves evaluating the advantages of each option and & BD [63], CRD * [47] \\  & determining the best alternative. & \\ \hline  & & The implementation of an agile approach in design & \\  & Management & management involves the ability to embrace changes flexibly & DS [64], SD [65] \\  & and continuously add value for both designers and clients. & \\ \hline  & & It is a visual tool for modeling networks that represents system & \\  & & elements and their interactions, facilitating problem & \\  & & decomposition and integration. & \\ \hline  & & This tool increases process clarity, promotes collaboration, and & \\  & facilitates communication among designers while strengthening & BD [66; 68], SD [65], \\  & workflow stability and reliability. & \\ \hline  & & It refers to the development and use of software to simulate the & \\  & & creation and operation of a building. The result is a detailed & \\  & & building model enriched with intelligent and parameterized & \\  & data, offering insights and analysis useful for decision-making & \\  & and process improvement in construction. & \\ \hline  & & \\ \end{tabular}
\end{table} 
Table 5: Lean tools applied to design (* Application is suggested: Building Design (BD), Social Housing Designs (SHD), Hospital Building Design (HBD), Hydraulic Infrastructure Design (HID), Concrete Reinforcement Design (CRD), Subway Design (SD), Infrastructure Design (ID), Structural Design of a Building (SDB), Engineering Design (ED), Housing Design (HD), Design Stage (DS).). Among the most commonly used tools in the design phase, Building Information Modeling (BIM), Last Planner System (LPS), and Target Value Design (TVD) stand out. LPS has been adopted for planning and scheduling activities in engineering design projects, optimizing task organization, and improving deadline compliance [74]. BIM enables the creation of detailed 3D virtual models, fostering communication and collaboration among various design stakeholders [68]. TVD is used to maximize the cost-value relationship of the project from its early design stages, ensuring that decisions reflect a balance between value and resources [60]. These tools have gained recognition due to the strong body of research supporting their effectiveness in design.