This is a case of replacing the existing metal halide lighting in a Slovakian automobile production factory with eco-friendly LED lighting. This project is a demonstration of replacing the lighting in the largest single factory in Europe and enhancing work efficiency through improving the environment of the workplace by not only achieving energy savings, but also by boosting the illumination index that falls below the EN Standard (300 Lux). In the future, the second phase of lighting replacement will take place at the same company.