Benchmark 11A
Common Themes: Systems
Grades 9-12, page 266

The successful operation of a designed system usually involves feedback. The feedback of output from some parts of a system to input for other parts can be used to encourage what is going on in a system, discourage it, or reduce its discrepancy from some desired value. The stability of a system can be greater when it includes appropriate feedback mechanisms.

See the general discussion in Unifying Concepts and Processes: Systems, order, and organization