Field Guide · Manufacturing · 8 min

The Clocks of Lean

Takt time, cycle time, lead time. Three clocks everyone mixes up — measured in the same units, answering completely different questions. Here’s each one, then the single relationship that decides whether your line can meet demand.

1 The demand clock

Takt time

Takt is the drumbeat of demand — how often you must finish one unit to keep up with the customer. You don’t choose it; the customer does. Speed the demand up and the beat gets faster.

1 unit
every beat

Takt = 84s

The pace you must hit. Available time ÷ customer demand.

27,000 s/shift ÷ 320 units = 84 s/unit

slower beatfaster beat ▶
Calculate your takt time →
2 The machine clock

Cycle time

Cycle time is how long a process actually takes — the time to complete one unit at a station, start to finish. It’s the one you measure with a stopwatch, and it’s set by your process, not your customer.

0units off the line

Cycle = 47s

How long the work actually takes. Measured, not chosen. Each time the bar fills, one unit is finished.

slowerfaster ▶
3 The customer clock

Lead time

Lead time is the one the customer feels — total elapsed time from order to delivery. Watch a single unit travel the line and you’ll see the truth: it spends almost all of its life waiting in queue, not being worked on.

Lead time

The clock the customer actually feels: from order placed to order delivered. Follow one unit and it spends almost all of that time waiting in queue — not being worked on.

order → … waiting … → delivered — the wait is most of it

Here’s how the clocks fit: lead time = every cycle time added up, plus all the waiting between steps.
Now put them together

Balance the line

Here’s the whole idea in one instrument. The dashed line is takt — the customer’s beat. The bars are your stations’ cycle times. Every bar has to finish inside takt, or demand walks out the door. Drag a station, or move demand, and watch what breaks.

Live · 5-station line✓ Line meets demand
Takt 84s
38sS1
52sS2
44sS3
61sS4
47sS5
Available time is fixed: one 7.5-hour shift = 27,000 seconds. More demand → shorter takt → the blue line drops toward your bars.
Takt time
84s
the beat you must hit
Bottleneck cycle
61s
Station 4 — slowest
Every station finishes inside takt (84s), with 23s of headroom at the bottleneck. Push demand higher and watch takt fall toward your tallest bar.
Why they get confused

Three clocks, three questions

Takt and cycle are both measured in seconds per unit and sound almost the same — that’s why people swap them. Lead time is a different kind of clock: not a pace, but how long one order waits. The cleanest way to keep them straight is the question each one answers.

TaktHow fast must we go?
CycleHow fast do we go?
LeadHow long does the customer wait?

Mix up takt and cycle and you staff the wrong number of stations. Confuse cycle and lead and you promise a delivery date you can’t hit.

Good to know

Frequently asked

What is the difference between cycle time and takt time?
Takt time is set by the customer — available working time divided by demand — and tells you how often you must finish a unit to keep up. Cycle time is set by your process: how long a station actually takes to complete one unit, measured with a stopwatch. Takt is the pace you must hit; cycle is the pace you have. When a station’s cycle time exceeds takt, that station can’t keep up and caps the whole line.
How do you calculate takt time?
Takt time = available production time ÷ customer demand for that period. If you run one 7.5-hour shift (27,000 seconds) and the customer needs 320 units, takt is 27,000 ÷ 320 ≈ 84 seconds — one finished unit every 84 seconds. Available time means real, workable time: subtract planned breaks and meetings, but not unplanned downtime.
Is lead time the same as cycle time?
No. Cycle time is how long the actual work takes at a station. Lead time is the total elapsed time from when an order is placed to when it’s delivered — and most of it is not work, it’s waiting in queue between steps. A part might carry only a few minutes of cycle time but sit for days of lead time. Lead time = every cycle time added up, plus all the waiting between steps.
Can cycle time be greater than takt time?
Yes, and it’s a problem. If a station’s cycle time is longer than takt, it finishes units slower than the customer needs them, so demand backs up behind it — that station is the bottleneck and it sets the pace of the entire line. The fix is to rebalance work off that station until every cycle time sits at or under takt, or to redesign the step.
How do you reduce lead time?
Because lead time is mostly waiting, the fastest way to shrink it is to cut the inventory and queues between steps — not to make the stations work faster. Reducing work-in-process, moving toward one-piece flow, and balancing the line so parts don’t pile up in front of a bottleneck all collapse lead time while the actual work content stays the same.
MS
Matthew Savas

Founder of Kaizumi, an AI-powered Lean training platform. More about Matthew →

Updated July 2026 · All figures are illustrative, created for teaching. Definitions follow standard Lean usage (takt = available time ÷ demand; cycle = actual time per unit at a step; lead = total order-to-delivery elapsed time).