Point calculations are done by hand only for simple situations, most commonly for small areas or vertical illuminance. Computer programs use this calculation method to check uniformity of illuminance in combination with the Lumen Method to check the quality of a lighting design. Some computer programs calculate the illuminance at many points on the workplane and then take the average maintained illuminance, thus avoiding the Lumen Method. The high number of calculations required to do this make it impractical to do by hand.
