The Theory of Constraints (TOC) is an effective tool for optimizing production processes by identifying and eliminating bottlenecks. This research developed an improvement model based on TOC, aimed at enhancing the efficiency and sustainability of operational systems. The model was applied at the UEB Fábrica de Acabado of the “Desembarco del Granma” Textile Company, which faced the challenge of increasing performance with minimal economic, environmental, and social impact. The approach integrated theoretical foundations and sectoral experiences, structuring a procedure in three phases, comprising 10 stages, four steps, and five actions organized in an operational sequence. Its implementation enabled the identification of the main constraint in the production process and the adoption of technical, organizational, hierarchical, and investment measures to improve the sustainable effectiveness of the critical operation and the overall performance of the UEB.