Balance the Line
Five stations, one drumbeat. Here's how work gets shared so the line flows — and what to do when it won't.
Every line runs to one beat: takt
Takt is the customer's pace — available time ÷ demand. Sell a car a minute and takt is 60 seconds. It's the line every single station has to fit its work under. Get below it and you keep up; go over and you can't.
A station's work is a stack of elements
A station isn't one lump of work — it's a sequence of small tasks, or work elements: Clip trim, Fuse box, Harness route… Time each one and stack them up, and the bar you get is a Yamazumi — a picture of exactly where every second at that station goes.
Some elements move, some don't
Look closer and the elements split in two. Boulders are bolted down — tied to a machine, impossible to split (a door comes off here). Pebbles are hand work you can pick up and hand to a neighbor. Balancing means rearranging the pebbles around the boulders.
Now stack every station — the imbalance jumps out
Line all five up against the takt line and it's impossible to ignore: one station pokes over takt while others sit half-empty. That's a Yamazumi of the whole line.
The bar over takt is a jam you can see
That over-takt station can't keep pace, so cars pile up in front of it — and the stations downstream starve, waiting for work that never arrives on time. Time and flow are the same story told two ways.
Now you balance it
Drag a work card off the overloaded station onto a lighter one — or use the − / + buttons. Watch the bars, the bottleneck, and the cars on the belt all move together.
Sometimes you can't balance it
Move every pebble off this station and it's still over takt — because its boulder alone exceeds the beat. No amount of reallocation fixes that. This one needs a process redesign — split the boulder, automate it, or change the work — not another round of balancing.
And takt never holds still
Demand drops, takt gets longer — and a line balanced for the busy season is now over-manned. The skill isn't balancing once; it's rebalancing fast. With your fixed/variable split and a reserve of pebbles, a takt change is an afternoon of moving cards, not a re-engineering project.
That's line balancing.
Share the work so every station fits under takt, keep the pebbles movable so you can rebalance when takt shifts, and redesign the boulders you can't move.
Build your own Yamazumi →Frequently asked
- What is line balancing?
- Distributing work elements across stations so every station’s cycle time sits just under takt — no station overloaded, none idle — and the line runs at one steady pace. In practice it also means keeping the line easy to rebalance when takt changes.
- How do you calculate the number of stations on a line?
- Add up all the real work content and divide by takt, then round up: stations = Σ cycle time ÷ takt. If 800 seconds of work runs at a 60-second takt, that is about 14 stations. You then load each to roughly 90% of takt, not 100%.
- What’s the difference between line balancing and takt time?
- Takt time is the single pace customer demand sets (available time ÷ demand). Line balancing is arranging the work so each station fits under that pace. Takt is the target; balancing is how you hit it.
- Why not load every station to 100% of takt?
- A line with no slack stops the moment anything varies — a quality check, a small jam, a slightly slow cycle. Loading to about 90% leaves a buffer that keeps the line moving and gives quality somewhere to live.
- What if a station’s work is over takt and can’t be moved?
- If a single fixed element (a “boulder” — bolted to a machine, impossible to split) already exceeds takt, no amount of reallocation fixes it. That station needs a process redesign — split the task, automate it, or change the work — not another round of balancing.
Related
Founder of Kaizumi, an AI-powered Lean training platform. More about Matthew →
Updated July 1, 2026 · Drafted with AI assistance and reviewed by Matthew Savas for accuracy.