Propuesta de mejora aplicando la metodología DMAIC en una planta inyectora de plásticos

In a constantly growing global plastics market, continuous process improvement has become essential to ensure quality and customer satisfaction, which in turn allows the company to maintain its competitiveness. This study focuses on the application of the DMAIC methodology to improve the manufacturing process of plastic caps in a medium-sized company with more than 30 injection machines. The analysis begins with the definition of the most important problems that affect the quality of the product, using tools such as the QFD matrix. After identifying that the variability of the quality of the final product must be reduced due to the amount of scrap used and the variability of the dimensions of the caps. Information on the relevant variables is then measured and collected to determine the magnitude of these problems. The analysis to determine the root causes of both problems is carried out using the Ishikawa diagram and R&R analysis, identifying that the lack of experience of the inspectors is the main cause of the problem of the high variability of the inspectors when measuring the variable cap diameter. And the high percentage of scrap use is the main cause of the problem of batches with inferior quality. Next, it is proposed that the personnel who measure the variable diameter of the cap should be trained. In addition, the standardization of raw material acceptance criteria is proposed, which are implemented and remeasured to evaluate their effectiveness. As part of the control stage, indicators and the tools to control them are established. Likewise, activities are proposed for quality management, including periodic audits and the promotion of a culture of continuous improvement. The systematic approach used is data-driven and has proven to be effective in addressing quality issues, reducing the variability of physical attributes associated with quality. This will improve competitiveness in the market. The results and recommendations derived from this study provide valuable guidance for quality management and continuous improvement in the plastic injection plant.