Required illumination levels in an electronics manufacturing facility were studied in order to provide feedback for architects and engineers. The study was carried out for the production floor of an electronics company in Ankara. The space considered was a Printed Circuit Board Assembly (PCBA) and Surface Mount Device (SMD) production department. The selected area was subdivided into different areas according to required illumination levels for each year. These levels were determined according to the specific work types over the total area according to each individual department. Data compiled by the field survey was analyzed and evaluated for investigating the relation of the potential effectiveness of the lighting systems regarding time, together with illumination levels needed for specific work areas. Changes in the sizes of areas needing various illuminance levels over past years were analyzed. It was found that there had been a decrease in the total required illumination levels.