One of the challenges faced by manufacturers of modular furniture is the occurrence of missing parts in products delivered to customers. Inefficiency in the packaging department poses significant issues affecting productivity, costs, customer satisfaction, and perceived quality. To tackle these challenges and minimize missing parts while improving processing times, a series of improvement measures is proposed based on Lean Manufacturing principles, utilizing tools such as Poka-Yoke and standardized work. Following the engineering design methodology, the proposals underwent validation through simulation using Flexsim software. The results enabled an increase in units dispatched from the packaging department and a reduction in the percentage of missing parts, ultimately leading to decreased costs associated with returns and replacements.