Overall Equipment Effectiveness (OEE) is a key performance metric that assesses equipment availability, productivity, and quality, which are vital for understanding performance and identifying losses in production processes. The document outlines the calculation of OEE and discusses the six big losses that can impact equipment efficiency and effectiveness, emphasizing the need for proper data collection and the importance of acting on identified shortfalls. Additionally, it highlights the benefits of OEE, such as facilitating change, benchmarking, and setting achievable targets.