What does Little's Law tell us?

Little’s Law is a fundamental concept in Lean and flow-based systems. It states that the average wait time (Lead Time) in a queue or process is proportional to the number of items in the system (Work in Process, WIP) divided by the average processing rate. The easiest, most direct way to achieve better flow (reduce wait time) is to reduce the queue length (WIP). SAFe 6.0 specifically cites Little’s Law as the basis for limiting WIP to optimize flow. Other options are incorrect or incomplete: B is false; long queues increase wait time. C is only partially true but not always possible; reducing queue length is usually easier and more controllable. D is incorrect; Little's Law applies to average, stable systems, not varying rates. E is unrelated to Little’s Law specifically.
Reference: SAFe 6.0 Website: Principle #6 – Visualize and limit WIP, reduce batch sizes, and manage queue lengths SPC 6.0 Guide: “Little’s Law demonstrates that reducing queue length is the fastest way to reduce wait time and improve flow.” ===========