I like to think of efficiency as a ratio, or fraction. Most often the input value of the equation is time or money. Efficiency is something almost everyone strives for in some aspect of their life.

Opinions expressed by Forbes Contributors are their own. Rhett is a DC based executive coach who covers entrepreneurship. Does that efficiency rate seem low for an average customer service agent?

Devices are designed to waste as little energy as possible. This means that as much of the input energy as possible should be transferred into useful energy stores. A very efficient device will ...

The efficiency of a device is a measure of how much of the input energy appears as useful output energy. The more energy a device wastes, the less efficient it is. useful output energy refers to ...