How to Create a Yamazumi Chart
A Yamazumi chart stacks each station's work content against takt time — the clearest way to see imbalance and waste on a line. Here is how to build one, step by step.
Steps to build a Yamazumi chart
- 1
Define the process and scope
Pick the line, cell or workflow to study and fix its start and end points. A clear boundary keeps the chart comparable over time.
- 2
Collect task times
Observe the work and time each task. Record several cycles and use the average — a single cycle hides the natural variation.
- 3
Categorise each task
Tag every task as Value-Added (changes the product the customer pays for), Necessary Non-Value-Added (required but not value, e.g. inspection) or Waste (waiting, walking, rework).
- 4
Calculate takt time
Takt = net available time / customer demand. This is the line on the chart every station must fit under.
- 5
Stack the bars
Draw one bar per station, stacking its task times and colour-coding by category, then add the takt line across the chart.
- 6
Analyse and rebalance
Bars over takt are bottlenecks; bars well under takt are under-loaded; large waste segments are your first targets. Move work between stations to level the load under takt.
Frequently asked questions
What does a Yamazumi chart show?
Each station's total work content, broken into value-added, necessary and waste time and compared against takt — making imbalance and waste visible at a glance.
How many cycles should I time?
At least five, and ten or more when the work varies, so the average reflects real conditions rather than one lucky or slow cycle.
How is it different from a normal bar chart?
It is purpose-built for balancing: bars are per station, segments are categorised by value, and a takt line shows the target — so it drives rebalancing, not just reporting.
Related lean tools & guides
From chart to balanced line
Yamazo Studio builds Yamazumi charts straight from production video and lets you rebalance against takt in drag-and-drop scenarios — offline.
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