Lean Inventory Tools – Poka-Yoke – mistakes | avoid | warehouse
Lean Inventory Tools – Poka-Yoke
What if you were perfect? What if no one in your company ever made a mistake? There would be no reworks or scrap material in your factory. Purchasing agents would never order the wrong material or parts. The warehouse would never send out an incomplete or incorrect order. Your drivers would never deliver to the wrong customer. There would be zero returns anywhere. What would be the impact on your inventory? Clearly, inventory levels in every part of your company would be lower.
In fact, some inventories, like factory rejects, would be zero. I think you’ll agree. This would be a huge competitive advantage for your business. Now, lean can’t guarantee to eliminate every mistake, but there is a lean concept that’s designed to help you reduce errors throughout your entire organization. It’s called poka-yoke, and it’s the Japanese word for mistake-proofing. And this is one of the easiest lean concepts to implement. You probably have already experienced poka-yoke.
The last time you placed your order at a restaurant, did the waiter repeat the order to you? That’s poka-yoke. The goal of poka-yoke is to prevent the error from happening. In the service industry, like in the restaurant example, the customer is asked to verify there are no errors. Once this is done the order moves forward. But what about poka-yoke in the manufacturing area? In assembly operations, for example, parts can be made so that they connect in only one manner. It’s not possible to assemble the component backwards, so reworks are avoided.
At a factory workstation, if four bolts are needed to perform the required task, the bolts would be provided in packages of four. When the package is empty, you know the task is complete and the product can be moved to the next workstation. Again, reworks are avoided. Poka-yoke can be implemented in just about any part of the organization. And remember, it’s all about preventing the error from happening in the first place. If you want to implement poka-yoke where you work, a good place to start is with a specific customer return. Ask why the customer returned your product. Then keep asking why until you discover where the error was made. That’s where the poka-yoke is put in place.
Poka-yoke may be rather easy to implement, but finding the true cause of the error is often not so easy. Many companies use small quality teams to explore this. Once you find the right place to add the right poka-yoke, you should be able to prevent that mistake from happening again. By reducing customer returns, you can improve customer service and lower the amount of inventory in the return cycle at the same time. That’s good news for everyone.