Manufacturing Execution Systems (MES) have become crucial in modern manufacturing, enabling companies to improve efficiency, monitor production processes, and optimize resource utilization. This thesis focuses on evaluating the benefits of MES implementation in One-of-a-Kind Production (OKP) companies, where production complexity and customization requirements pose significant challenges. The research is based on a case study of a company specializing in the fine-tuning phase of prototype manufacturing, a critical process that ensures the final product meets customer specifications. To assess the impact of MES, the evaluation objectives were first defined to ensure alignment with real industrial needs. The study then involved mapping the fine-tuning process to provide a comprehensive representation of its workflow, highlighting critical areas where MES data could offer the most significant improvements.