Visual display, which is usually electronic, used to convey the current "scorecard" status of a process. Andon boards are commonly used in manufacturing plants to display production relative to target, current demand rate (Takt Time), and quality performance. They may also be used in call centers to convey the performance metrics such as average call time, average wait time, and abandonment rate.
Andon boards display current production information such as actual production vs. target, generally on a daily or shift-by-shift basis. The concept can also be applied to service operations, such as call centers or retail environments.
An Andon Board example from a Virtual Factory: - http://www.taylor-home.com/VF/2_1_3.html