Textile SMEs currently have a high demand for orders; however, there is a trend of increasing customer dissatisfaction, which is mainly related to shortages, low product quality and failure to meet deadlines. Therefore, a model was developed using the Lean Manufacturing methodology and analysis tools, including 5S. The case study is about a garment manufacturer and merchant SME in Peru, which developed a model to improve the low level of service they provide to their customers. The investigation shows the improvement of the level of service from 70% to 93%, likewise in the economic aspect a saving of 25,363.53 soles is shown, which represents 77%. This model proposal was implemented through the pilot test and simulation through the Arena V16 software, it also shows that the application of the Lean methodology together with analysis tools provide an improvement in processes such as warehouse management and quality. This study can serve as a guide to lay the foundation for business improvement for SMEs facing similar quality and logistics issues that is needed to improve service level growth.