The textile industry is an important foundation of Ecuadors economy because of its contribution through the generation of jobs for unskilled labor and tight integration with other industry such as the agricultural industry, livestock, plastics and chemistry. Within this sector is sub sector Apparel, which is taken as a reference and represents 27 percent of production in the Textile Industry. The project aims to develop a methodology to transform small and medium companies to lean manufacturing Enterprises. It seeks to define and evaluate administrative, production and service processes in a textile company which manufactures garment apparel, define problems in these processes, raise improvement plans and recommendations for themselves and determine a simulation model to search for the feasibility of the proposed improvement model designed. Some of the most important problems identified in the companies in this sector are the following: the high number of errors in production processes described informally by officials; a poor system for inventory control of raw materials; work in processes, finished products, production processes, and a disorganized workplace-office.