The purpose of this research is to evaluate the effect on productivity of the application of the 3P (Production, Preparation, Process) Methodology on manufacturing and assembly production processes, in relation to ventilation and air extraction products. With this goal in mind we intend to review two cases of process improvements that were implemented in Mexico, wherein the components of the 3P Methodology will be analyzed to relate their importance with the results and its impact on different measurable factors related to productivity, such as standard product cost and percentage of defects. Data sources of a Transnational Company (Based in the United States) were used from 2017 to 2019. The results demonstrate the effectiveness of the 3P methodology in improving production processes in Mexico, that were later implemented in the United States, impacting positively and transcendentally on a higher level of productivity.