From our analysis of the situation within a manufacturing company in the metal-mechanical sector in Lima, Peru, we found problems due to the noncompliant products index. They originated mostly during the galvanizing process, for which analysis of the current situation was initially developed. To reduce nonconforming products, we designed and implemented a proposal using lean manufacturing tools. Then we validated the attainment of positive results compared to the initial situation. For example, we achieved a 6% reduction of nonconforming products, a 10% decrease in claims, a 6% reduction of reprocessing, and a 0.8% lower percentage of elimination.