The fast-food industry, particularly in Latin America and Peru, has grown rapidly due to urbanization and rising middle-class demand. However, this sector faces critical supply chain challenges, including inefficiencies in demand forecasting, supplier selection, and process standardization. This research addresses these challenges by proposing a comprehensive supply management model integrating Sales and Operations Planning (S&OP), the Kraljic Matrix, and advanced demand forecasting techniques. The model was tested in a case study of a fast-food franchise in Lima, resulting in a 13.95% improvement in the Fill Rate, a 15.85% increase in OTIF, and a 25.49% reduction in cycle time. These outcomes highlight the model's potential to significantly enhance operational efficiency and customer satisfaction. This study provides valuable insights for both academia and industry, promoting further exploration of integrated supply chain management practices in fast-food operations.