The Ohno Circle

At Toyota, having engineers or managers stand for a long time inside a chalk circle is one of the best-known learning practices associated with TPS. The method is known as the “Ohno Circle” because it is commonly attributed to Taiichi Ohno.

The purpose of this observation exercise is to understand processes on site and recognise waste (muda), unevenness (mura) and overburden (muri). By forming our own observations first, we work on the difference between looking and seeing.

What happened inside the circle?
The person standing inside the circle was expected to:
🔶 Watch movements
🔶 Notice waiting
🔶 Observe operator behaviour
🔶 Understand material flow
🔶 Identify departures from standards

In the first few minutes, it often seems that “there is nothing to see.” Over time, however, the following become visible:
⚫ Brief moments of waiting
⚫ Unnecessary walking
⚫ An irregular rhythm
⚫ Recurring disruptions
⚫ Hidden bottlenecks

Why was this apparently simple method so effective?

Because:
⚠️ The human mind tends to jump to quick solutions
⚠️ Managers often fall into the trap of premature diagnosis
⚠️ Understanding real problems requires patient observation

Let us separate observation from interpretation. We should record what happens before jumping to a solution. Then we speak to the person doing the work to fill the gaps in our observations.

How can you apply it on the shop floor?

1. Select a safe observation point and a task to observe; explain your purpose to the employee.
2. You can allow 20–30 minutes for an initial trial. This is a starting range I recommend, not a fixed TPS standard. Adapt the duration to the work cycle.
3. Record walking, waiting, stoppages and repetitions as observations; keep interpretations of causes separate.
4. Review the notes with the person doing the work. Compare different cycles before generalising from a single observation.
5. Select an improvement experiment and follow up its outcome.

A task that appears ordinary at first may generate new questions as we watch it closely. Learning to see also takes practice.