Apply Little's Law to predict how long work will spend in your process — so you can manage queues, set realistic delivery promises and target WIP reductions.
Enter your current WIP and throughput on the left, then press Calculate.
Little's Law states that average lead time equals average WIP divided by average throughput. It applies to any stable system — factories, hospitals, software teams, call centres — making it the most widely-used flow equation in Lean.
If throughput is fixed by your process capability, the only way to reduce lead time is to reduce WIP. Halve the WIP, halve the lead time. This is why visual boards, WIP limits and Kanban work so powerfully.
Use this lead time as the basis for delivery dates and customer promises. If a new item joins the queue today, expect it to take roughly this long to come out the other side — assuming no priority changes or capacity shifts.