Difference between Poka-Yoke and Red Rabbit


I am a Quality Engineer on Wire Harness Manufacturing working with OEM's on Automobile Industry, following the principle of IATF 16949:2016 Quality System.

I would like understand one thing; On IATF 16949:2016, Article 10.2.4 Error Proofing;
It states that the the organization shall have an proper error proofing methodologies and shall have process control point documented.
The methodologies shall be documented with process risk analysis(e.g PFMEA) with their details and shall be documented on frequency with control plan.

As an company, We are using Poka-Yoke harnesses to understand if our processes detect the nonconformities.(As an Electrical Connectivity, We are currently using poka-yoke system for Terminal Position Out and Wrong Addressing nonconformities)

My questions is; What is the difference between Poka-Yoke and Red Rabbit methodology?
From my understanding; Poka-Yoke is a process system controller, Red Rabbit is more of an process operator controller, as we can see on attribute MSA, We are usually using Red Rabbit parts to understand the operator decision-mechanism.

Could someone give me an perspective on the difference between Poka-Yoke and Red Rabbit.

Many thanks for answering.


Forum Moderator
Poka Yoke is the actual mistake proof (e.g., sensors). Red Rabbit testing is the practice of verifying the effectiveness of the Poka Yoke by running known defective product through the Poka Yoke to verify that it works as intended.
We are using Poka-Yoke harnesses to understand if our processes detect the nonconformities.
This would be a red rabbit test.

John Predmore

Trusted Information Resource
Poka-Yoke is error-proofing which makes a mistake impossible (or impossible to not detect). If you make a wire harness and the connector is not symmetrical left-to-right, a poka-yoke would be a fixture which holds the connector during assembly where a reversed connector will not fit in the fixture. Another example might be if the connector will fit in the fixture upside-down, but then the opening is on the opposite side and the wires are not long enough to reach the opening.

A Red Rabbit is a test of your quality control measures. Suppose you mix a wrong part-number connector into a batch of connectors during a wire harness build, on purpose but without the worker's knowledge. The purpose of this experiment is to find out if your poka-yoke fixture will prevent the mistake, or if the worker will notice the error and react appropriately. Your control plan may call for a red rabbit test once a month (or whatever) to keep your workers paying attention. Of course, the engineer running the test must maintain control so that a non-conforming part in an assembly which escapes detection is not actually shipped to a customer.

If you rely on software or an automatic test to implement your poka-yoke, the poka-yoke itself should be tested occasionally. For example, if you rely on a continuity test to light a red bulb whenever there is an open circuit or short, what happens when the contact pins get stuck or corroded, or the red bulb burns out and no longer lights?


Thank you for your kind answers, it gives the glimpse of differences between them with the understandable examples as well.
Much appreciated.
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