Poka Yoke is a Japanese phrase that simply means making something ‘fail safe’ or mistake proof. Poka Yoke was devised within the Toyota Production System when it was originally defined as being ‘baka yoke’ which in English can be translated as idiot proof or foolproof.
However, after it began to be used, it was then changed to Poke Yoke, meaning mistake proof.
Poka Yoke is central to the concept of ‘Lean’ thinking, which aims to reduce waste and make sure that everything and every process is as efficient as possible.
Poka Yoke In Action
Poka Yoke is any process that can stop mistakes being created, thereby ensuring that there are no defects within the production process. So if a machine is designed to stop or at least sound a warning signal if it is not aligned correctly then this is ‘Poka Yoke’ in action. The operator will be alerted to the fact that the machine has not been correctly aligned and instead of faulty goods being created, or the machine continuing and then perhaps breaking down the operator will take the necessary steps to ensure that the problem is resolved before the faulty goods are created or before the machine breaks down.
This concept of stopping defects or mistakes from happening is central to Poka Yoke thinking. It is not about rectifying mistakes or defects; it is about ensuring that they simply do not happen.
Mistakes Will Happen!
The ‘creator’ of Poka Yoke, Shigeo Shingo was quite honest about mistakes and how they happen. He stated that mistakes are an integral part of any mass production process; the more you produce, the more likely you are to have mistakes.
However, he argued that mistakes need not result in defects or substandard work being created. If a company devises enough Poka Yokes, then it will ensure that mistakes are identified and then resolved before the defects happen and when there are no or very few defects, then the operating costs of a company will be substantially reduced.
How Can Poka Yoke Improve Business?
The concept of Poka Yoka is both brilliant and incredibly simple. If a company makes photoframes, but around 5% of the frames produced do not meet quality control standards, because they are damaged in production, then this has a serious effect on the company’s profits.
However, if the company introduce ‘Poka Yoke’ techniques to ensure that at least 99% of the frames produced are fit for purpose and meet quality control targets, then the company will have substantially more profits.
Poka Yoke need not be terribly complicated. Even having staff visually check products at the early stages of production can be ‘Poka Yoke’. This can ensure that all products are fit for purpose when they progress through to other stages of production. Mistakes can be easily rectified the earlier they are spotted, so instead of defective goods, the end result is high quality goods that all pass any quality standards.
Poka Yoke can even involve markings on the floor that show an operator where he or she must stand in order to operate a piece of machinery. Basic as it may sound, if they do not stand in the right position there may be a risk of the machine not being loaded correctly and this can result in the machinery being damaged. Painting the correct standing position on the floor is a quick, easy and cheap way of ensuring that the machine will be loaded correctly and there is no possibility of damaging the machine – simple, but at the same time brilliant: just like Poka Yoke!