## 3 Search Results and Classification
### Construction/Manufacturing Time  
In 38 studies, qualitative or quantitative aspects were reported, or statements were made regarding the construction time associated with the use, application, or implementation of industrialized construction systems. Data on performance and background on traditional construction systems, such as masonry walls, were also provided. Figure 4 summarizes the data reported by the authors, where the reductions or percentage increases in construction times were grouped. The figure shows a trend towards reducing construction times for building projects considering the use of prefabricated or modular construction systems. In studies M3, M4, M7, M8, M13, P22, P23, P30, P45, P61, P62, and P67, a reduction in manufacturing time was reported (ranging from 9% to 50%), with notable contributions from the United Kingdom. However, there was also participation from countries such as Chile, Italy, the United States, New Zealand, Portugal, and Australia, among others. In contrast, in the work M10, an increase in this indicator (32%) was reported, which is attributed to a project from China, where a modular system based on steel and concrete was used, leading to slower fabrication times for the pieces and components compared to other materials. Of the studies that reported background, 76% correspond to prefabricated systems and 21% to modular systems, and only one study (3%) was associated with traditional systems. Additionally, two prefabricated systems from Italy and the United Kingdom (P22 and P62, respectively) stood out again, each reporting a time reduction that could reach up to 50% of the total project. Then, two modular projects (M8 and M13) from the United Kingdom and Chile, respectively, reported a 40% and 44% reduction in construction time. Several of the reported indicators lack data associated with the specific construction performance of the various construction systems. In 19 studies, no quantitative data were reported, but it was declared that there was a time reduction when using industrialized construction systems instead of traditional systems. Only one study reported an increase in project execution time with the use of industrialized systems, mainly attributed to the complexity of some industrial processes, low knowledge of the techniques, and preparation of the construction site where these systems will be implemented. In study P28, two highly relevant projects for industrialized construction were reported, referring to the construction of two hospitals in China in 10 and 18 days. This is a significant milestone and poses a challenge for global construction, as it pushes the limits of companies to minimize project execution times. Overall, there is high variability in reports regarding construction times. For example, in study P55, performance data for prefabricated construction was provided, showing that it took 10 weeks to construct 1000 [m\({}^{2}\)], while the performance of a traditional system, with a base performance of 2.11 [m\({}^{2}\)/h], equates to 844 [m\({}^{2}\)] for the same 10 weeks (considering 40 working hours per week). Based on these data, it can be said that prefabricated construction is approximately 16% faster than traditional construction. Studies M3, M7, P21, P41, P48, P54, P55, P61, P69, and P70 indicated that prefabrication and modular construction positively influence construction times. The use of 2D modules with CLT systems is faster than 3D modules. Modular production allows much of the work to be performed off site, optimizing the overall project time. The efficiency of these systems is further increased when combined with simultaneous work techniques on site. These methods not only reduce construction times but also improve design quality, flexibility in material selection, and efficiency in quality control and productivity. Additionally,  
Figure 4: Time variation of industrialized projects/solutions with respect to traditional projects/solutions.