A bottleneck or constraint is anything that restricts the throughput of a system. A constraint within an organization would be any resource where the demand for that resource is greater than its available capacity. In order to increase the throughput in a system, the constraints must be identified, exploited if possible, and removed if necessary. Bottlenecks occur in many parts of our lives: the exit to a concert hall, rush-hour traffic, the telephone receptionist, or the cashier in a cafeteria line. You can usually find bottlenecks by looking where people are waiting or where work is piling up.