A fundamental premise of lighting is that light has value. This is easy to show when the choice is between no light and some light. When the choice is between some light and more light, it is much more difficult to demonstrate. Because of this difficulty, lighting recommendations have been based on consensus judgments of the value of light. There is no formal connection between these judgments and the basic premise upon which they are founded so they are not guaranteed optimal.

In this paper, we report on a successful attempt to formally analyze a practical problem: an evaluation of the relative economics of lumen maintenance control system vs the standard no-controls system. We digress briefly to describe a lumen maintenance control system.