From Thayer Solutions:
Lighting Design is a design tool intended to speed the process of designing indoor lighting systems for simple rectangular rooms with a single Luminaire Type. For indoor lighting situations, the Zonal Cavity Method is used with data from manufacturer coefficient of utilization tables. It is ideal for designing classrooms, warehouses, offices, and other common rectangular applications. The program quickly calculates fixture quantities, spacing, average illuminance, and fixture quantity per circuit.