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.”

===========