Enter your process steps, each step's daily capacity, and the work currently sitting in queue. Little's Law does the rest: your true lead time, your constraint, and how close each step is to breaking. No stopwatch required — yesterday's numbers are enough.
A process bottleneck is the step with the lowest capacity in a sequence — the constraint that determines total throughput no matter how fast every other step runs. Adding capacity anywhere except the bottleneck produces work in progress, not output.
Which step constrains your process, your current throughput ceiling, and how much additional output you would gain by relieving that specific step rather than any other.
Operations leaders deciding where to add headcount, automation, or capital — and anyone who has added resource to a process and seen no improvement in output.
The constraint sets the pace of the entire line. Improving a non-constraint step raises WIP and cost without raising throughput. Once you relieve the constraint, it moves — expect a different step to become the bottleneck.
Measure the capacity of each step in the same units and time base. The lowest-capacity step is the constraint. In practice it is also usually the step with the largest queue of work waiting in front of it.
Because throughput is set by the slowest step. Speeding up an upstream step only pushes more work into the queue at the constraint; speeding up a downstream step leaves it idle while it waits.
The constraint moves to whichever step now has the lowest capacity. Bottleneck management is continuous, not a one-time fix — which is why the calculation is worth repeating after each change.
No. It is often a policy, an approval, or a batch rule. A step that waits for a weekly sign-off has an effective capacity set by the meeting schedule, not the work.
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Built by Windy Hill Partners, a process improvement consultancy applying Lean Six Sigma and DMAIC. Every tool here is free and ungated at the point of use.