The takt time formula
Takt time = available time per day ÷ customer demand per day
Available time is planned working time less planned breaks — not machine capacity, and not overtime. Two 8-hour shifts with 30 minutes of breaks each give 2 × (28 800 − 1 800) = 54 000 seconds a day.
Daily demand is the customer's demand for the product family divided by the working days in the same period. 12 000 parts a month, at 5 days a week and 48 working weeks a year, is 12 000 ÷ 20 = 600 parts a day.
So takt is 54 000 ÷ 600 = 90 seconds: the customer takes one part every 90 seconds, and every process in the value stream has to keep up with that over the day.
Checking a process against takt
A stopwatch cycle time under takt doesn't mean a process can keep up. Stoppages and rework eat into it. Compare the effective cycle time instead: cycle time ÷ uptime ÷ first-pass yield. A welding cell with an 80-second cycle, 85 % uptime and 96 % first-pass yield is effectively 80 ÷ 0.85 ÷ 0.96 ≈ 98 seconds — over a 90-second takt, although the stopwatch said it had 10 seconds to spare.
Over takt means the line can't keep up without overtime or extra stock. Close to takt (above about 90 %) means any wobble will show. Both become improvement targets — uptime, yield, changeovers or the work content — when you design the future state.
From takt to a value stream map
Takt is the first of the future-state questions in value stream mapping, and every later decision — where work can flow, where pull replaces the schedule, which process sets the pace — is judged against it. The free Value Stream Builder takes the same numbers, draws the current-state map with the standard symbols, turns stock into days of demand and guides you through the rest. The VSM symbols cheat sheet and the worked value stream map examples show what the finished maps look like.
Questions
What is takt time?
Takt time is the rate at which the customer buys: the available working time divided by customer demand for the same period. If a line works 54 000 seconds a day and the customer needs 600 parts a day, takt is 90 seconds — one part every 90 seconds.
How do you calculate takt time?
Takt time = available time per day ÷ customer demand per day. Available time is planned working time less planned breaks: shifts × (hours per shift × 3 600 − break minutes × 60). Daily demand is the period's demand divided by the working days in that period.
What's the difference between takt time and cycle time?
Takt time comes from the customer: how often they need a part. Cycle time comes from the process: how often a part actually comes off it, timed with a stopwatch. A process can keep up when its effective cycle time — cycle time ÷ uptime ÷ first-pass yield — is under takt.
What's the difference between takt time and lead time?
Takt time is a rate (seconds per part). Lead time is a duration: how long one part takes to get through the whole value stream, mostly waiting in stock. A value stream map shows both — and usually that the lead time is days or weeks while the processing time is minutes.
Should overtime count as available time?
No. Calculate takt on planned time. Overtime that's needed every week is a sign that a process can't keep up with takt — a problem to solve, not time to plan with.
What is pitch?
Pitch is takt time multiplied by the pack-out quantity: the time it takes to make one container. At a 90-second takt and 20 parts to a box, pitch is 30 minutes. In a lean value stream, work is released to the pacemaker one pitch at a time.