Each production facility has its maximum theoretical capacity, which must be achieved without any disturbance and quality loss. Of course, it is impossible to achieve completely zero loss or error in actual production. OEE is an independent measurement tool used to express the ratio of actual production capacity relative to theoretical capacity, grouped by key elements of availability, performance, and quality index.

Lean production emphasizes customer-oriented, waste elimination, and continuous improvement as the core, and obtains the maximum benefit with the least input cost.