## 3 Materials and Methods  
The case study was the research method used. It is an empirical study that intends to determine or corroborate a theory. It suits operational and organizational dilemmas and allows the implementation of improvements to combat verified problems ([PERSON] et al., 2018). In this type of method, the central questions are \"how\" and \"why,\" and the researcher cannot control events. According to [PERSON] [21], the case study belongs to the typology that qualitative research uses. The context addressed in qualitative research is a real context. The data collection takes place directly at the research site, and descriptive data collection techniques are used [21]. To this end, the research design adopted for this article was focused on the PDCA cycle (Plan, Do, Check, and Act). In the initial phase of this study, it was necessary to gain an understanding of the factory's background and production process, from conformation to the selection section. This was achieved through direct observation and interaction with employees from different sections of the factory. It was also necessary to understand how the equipments work, specifically the ones more energy intensive. In the second phase, the focus was on the research objectives. Brainstorming sessions were conducted with employees at different hierarchical levels (from shop floor workers to the factory director) to explore solutions for improving equipment, methods, and processes. In these sessions, the importance of suggesting energy efficiency measures and monitoring the measures already implemented was perceived to not only anticipate their impact but also the impact of those already implemented. It is important to note that, bearing in mind the disorganization of the records of energy consumption, it was necessary to process and digitize them. Then, the follow-up on the measures implemented and the suggestions of others was conducted. To carry out the energy characterization of the equipment, a thermal analysis was performed, in particular on the different furnaces, using a thermographic camera. The data provided by the company was also analyzed to determine its energy needs. In turn, using the RESTcreen(r) software, the feasibility of implementing renewable energy sources such as photovoltaic panels and wind turbines was studied. The implementation of energy management systems was also suggested. At a later stage, the number of parts retouched was evaluated. Through these data, the energy gains represented by the reduction in the amounts of retouching were estimated, and the impact of this reduction on energy indicators was also analyzed. Quality control was carried out to reduce the percentage of retouched parts. On the other hand, the auditor was also accompanied in the data collection to conclude the measures implemented before this study and their effectiveness. In that analysis, some useful tools were used, standing out: \begin{table}
\begin{tabular}{c c c c c c c} \hline \hline \multirow{2}{*}{**Energy**} & \multicolumn{2}{c}{**Final Energy**} & \multicolumn{2}{c}{**Primary Energy**} & \multicolumn{2}{c}{**CO\({}_{\mathbf{2}}\) Emissions**} \\ \cline{2-7}  & & **Unit** & **[toe]** & **\%** & **tCO\({}_{\mathbf{2}}\)** & **\%** \\ \hline Electric Energy & 50,089 & MWh & 10,769 & 27.9 & 23,541 & 24.0 \\ \hline Natural Gas & 25,556 & t & 27,513 & 71.5 & 73,836 & 75.3 \\ \hline Liquefied Petroleum Gas & 28.3 & t & 31.8 & 0.1 & 84 & 0.1 \\ \hline Diesel & 177 & t & 181 & 0.5 & 561 & 0.6 \\ \hline Gasoline & 1.3 & t & 1.4 & 0.0 & 3.8 & 0.0 \\ \hline Total & & & 38,496 & 100 & 98,025 & 100 \\ \hline \hline \end{tabular}
\end{table} 
Table 1: Annual primary energy consumption and CO\({}_{2}\) emissions from IECMS installations [20]. * The Pareto chart: to display quality problems and present improvement projects that arise according to their importance [22]. * The Ishikawa diagram is a schematic diagram intended to represent and simplify complex problems through the identification and grouping of their different causes [23].