What is Poka-Yoke in Manufacturing?

Poka-yoke, or mistake-proofing, is a Japanese lean manufacturing strategy for eliminating human mistakes during production in order to prevent product defects. In Japanese, poka-yoke translates roughly to “avoid” (yokeru) and “mistakes” (poka). Lean manufacturing is the act of reducing waste while maximizing productivity to boost shop floor operations.

Essentially, this technique works to remove product deficiencies by preventing or immediately fixing human mistakes as they occur. Leaders use lean manufacturing tactics like mistake-proofing to cut waste, reduce costs, optimize procedures, increase innovation, and decrease time to market.

Learn when to apply poka-yoke in manufacturing and how to do it:

Three types of poka-yoke
When to use mistake-proofing in manufacturing
How to implement poka-yoke in manufacturing

Three types of poka-yoke

There are three types of poka-yoke used for product quality assurance: contact, fixed-value, and motion-step methods.

The contact method detects deviations in product form, position, and other physical attributes through smart devices that monitor each production part. For example, it can be used to identify goods that have shifted out of place on the assembly line, recognize when temperatures exceed regulations, and more.

Next, the fixed-value method is applied when a process needs to be executed a specific number of times, or when a fixed number of parts need to be in the same package. Typically, a signal goes off to indicate that a product is not ready for the next step in the production process.

Lastly, the motion-step method uses sensors and devices to track if a step has been completed on time and in sequence. An indicator light, for instance, will turn on if a step in the machine cycle is not completed in the right sequence or timeframe.

When to use mistake-proofing in manufacturing

Poka-yoke can be implemented at any stage of the production process where human mistakes are likelier to affect product flaws and issues. So it is critical to assess production procedures and pinpoint potential issues before applying mistake-proofing.

Examples of when to use poka-yoke methods include:

Machine operations to ensure equipment is running smoothly and industry best safety practices are followed
Quality inspection procedures to test for product defects before customer distribution
Process flow to prevent or correct products that may not finish on time or have defects
Handling of raw materials to guarantee items are safely moved and stored at the necessary workstations
Shop floor operations to gauge if the correct parts were assembled in the right order with the proper specifications
Packaging and shipping to ensure goods are delivered in pristine condition and on schedule

How to implement poka-yoke in manufacturing

Implementing poka-yoke can help revolutionize the entire production process and give companies a competitive edge. Basically, it works to eliminate all human error to ensure quality products for distribution, resulting in customer satisfaction.

Follow the steps below to get a better idea of how to successfully apply mistake-proofing to everyday processes.

Step 1: Pinpoint root cause of issue

The first step is to identify where the human error is occurring and what is causing it. Keep in mind that the problem may be the result of frequent worker mistakes or a defective machine. It’s important to carefully inspect each of your production processes to see where the issue is coming from to find the root cause.

Step 2: Apply appropriate poka-yoke technique

Once you know where the problem occurs, you can apply any of the three poka-yoke methods (contact, fixed-value, and motion-step) to troubleshoot it. You may have to apply all three techniques if a series of mistakes are found throughout different stages of the manufacturing process.

For example, you could use the contact method to detect issues stemming from an item’s physical appearance (such as irregular form, size, etc.).

The fixed-value method, meanwhile, could be helpful if a process is not being completed the right way. A signal will go off to alert the operator if a step was missed prior to the release of a product for the next stage of production.

Or you could use the motion-step method to monitor whether a production step has finished within the appropriate timeframe and sequence.

Step 3: Ensure production procedures are standardized

Having standardized procedures in place can help reduce product defects in production processes. Applying solely poka-yoke techniques without standardizing production procedures is useless.

Workers should know how to troubleshoot problems correctly each time. This is where standardization can help. Standardizing processes ensures all employees are following the same set of guidelines for each shop floor process each time.

Step 4: Train workers

Poka-yoke methods are only helpful if each employee is trained on how to apply them to production. Initiating training programs can be a great way to teach staff how to carry out techniques that are best suited for each manufacturing process.

Consider adding information on poka-yoke to your standard operating procedures (SOPs) guide to help workers gauge what is required of them to perform each task.

Step 5: Implement software for long-term error detection

A connected worker platform is a digital software tool that helps continuously detect errors. This software allows you to connect all of your shop floor smart devices to a centralized management platform and test production processes for errors.

Step 6: Monitor successful implementation of poka-yoke

Lastly, track how well your production processes are performing now that you’ve implemented poka-yoke strategies. Look for errors that may be impacting your overall performance to continuously improve everyday operations.

Augmentir is here to help you reap the benefits of successful poka-yoke execution. We are the world’s only AI-powered connected worker solution to optimize assembly line operations to reduce human error.

Request a live demo today!