Poka Yoke

The term Poka Yoke comes from the Japanese and can be translated into German as "avoidance of unintentional errors". It was coined in the 1960s by Shigeo Shingo, a quality engineer at Toyota. "Poka" means error and "Yoke" means avoidance.

Poka Yoke is a concept or method for quality improvement and product optimization, whereby Shigeo Shingo started from the insight that people and systems are not able to completely avoid involuntary errors. The aim is to exclude possible sources of error in a process from the outset or to detect errors in production at an early stage. The focus here is on areas of application in which people in particular can make mistakes due to carelessness or fatigue, for example.

Poka Yoke is usually used as a reactive method to prevent errors. This means that measures have to be subsequently integrated into existing production systems or process steps. However, even if this is often associated with costs and effort, it is generally more cost-effective for companies to eliminate potential errors during production.

The Poka Yoke principle is also present in many of our everyday processes. For example, when inserting the SIM card into the card slot, it is prevented from being accidentally inserted the wrong way round from the outset, as it only fits into the SIM card slot in the correct orientation due to its shape. Many new cars have a system with sensors and warning messages that warn or inform the driver of possible dangers and errors.

Poka Yoke for error prevention in everyday life

Even though we come into contact with the Poka Yoke principle almost every day, we are sometimes not even aware of its use. One example: when withdrawing money from an ATM, it is ensured from the outset that the user cannot forget the debit card in the ATM, as the money is only dispensed once the card has been removed by the user. Mistakes and errors in the process can therefore be effectively prevented by Poka Yoke.

Poka Yoke is not only used to prevent errors in physical products, but also in digital applications. In order to develop high-quality software, it is important to design it in line with the user's expectations. Thanks to Poka Yoke, the user should be able to operate the software easily and without costly errors.

An example of Poka Yoke as a method in the software application is the display of password strength to motivate the user to use a secure password with combinations of characters and numbers. The search engine function with automatic suggestions and spelling corrections for search queries also serves to avoid unintentional errors.

The main goal and basic idea of Poka Yoke is therefore to completely eliminate errors in the process in order to ensure error-free production. However, it is impossible for humans to completely avoid errors. By using Poka Yoke techniques, at least the recurrence of the same errors is prevented and the aim is to minimize sources of error.

Examples of the poka-yoke method

CEE plugs have different colors and contact arrangements depending on the voltage and frequency in order to avoid confusion. This means, for example, that a 16 A plug cannot be inserted into a 32 A socket.
TAE telephone plugs cannot be inserted the wrong way round. The same applies to USB plugs. Newer plugs work on both sides.
In Germany, ATMs only dispense money once the card has been removed. This prevents the card from being forgotten.
Due to their shape, SIM cards can only be inserted in the slot in the correct orientation.
Eye color query in forms for customer service employees to ensure eye contact with the customer.