This master's thesis explores the application of ERP (Enterprise Resource Planning) and MES (Manufacturing Execution System) systems in improving the operational management of small and medium-sized enterprises, using the company Termo Sušak d.o.o. as a case study. The goal was to analyze the company’s operational challenges, such as uncoordinated communication, inaccurate inventory tracking, and complex project management, and to implement the Odoo ERP system to enhance these processes. The ERP system implementation included the integration of warehousing, procurement, sales, finance, and project management functions, resulting in significant improvements in accuracy and efficiency. Automated inventory tracking enabled precise control of material, while faster proposal generation allowed the company to respond more swiftly to market demands. The ERP system also simplified accounting processes, enabling automatic report generation and more transparent financial management. The study demonstrated that the implementation of ERP and MES systems significantly reduces operational costs, improves interdepartmental coordination, and enables strategic decision-making based on reliable data. The Odoo ERP system also serves as a foundation for the company’s future growth and development, ensuring better adaptation to market demands and greater competitiveness.