Zero-defects Production due to Poka Yoke


People make mistakes. Mistakes are what makes us human. You can train people to make fewer mistakes, but you won’t be able to train a person that makes no mistakes. Fortunately, there are plenty of other techniques to avoid mistakes. An Intelligent product design, for example. The SIM card is missing a corner so it only fits in your smartphone one way. The French fries scoop at McDonalds immediately scoops the right portion and we all use the spelling corrector in Word.

These techniques are also known as poka yoke. Poka yoke is a Japanese technique developed at Toyota. The translation is as follows: avoid unintentional errors. Poka yoke is a technique used to prevent errors.

Errors cost money. Repairs, damage claims, waste are all unnecessary costs. And they can be perfectly avoided. Poka yoke is a company-wide strategy where errors are unacceptable. You implement various systems that make it impossible for mistakes to occur. In this way, poka yoke also ensures fewer accidents and a safer work environment. A win-win situation! 

Errors vs. defects

Every defect starts as an error. An error becomes a defect when that error reaches the customer. Poka yoke focuses on preventing this. Defects can lead to irreparable damage to your company or huge costs.

Fun fact: For each step that a faulty product progresses in the production process, the cost for correcting the fault must be multiplied by 10. This is better known as the 1-10-100 rule.

Therefore it is important to detect errors as soon as possible. Because fixing errors leads to unnecessary costs. In addition to limiting costs, you also reduce the chance of defects and gain the possibility to easily make adjustments so that similar errors are avoided in the future.

Error prevention

A swift error detection is crucial. But it is even better to avoid errors because:

Prevention is better than cure!

The big question is of course: How do you prevent human errors? Good training is obviously important but a misunderstanding or forgetfulness can easily happen. Therefore, One of the most important rules within poka yoke is: Don’t change the people, change the environment! By adapting the work environment and choosing an intelligent product design, you can manipulate your processes so that it becomes impossible to make mistakes.

Poka yoke on the factory floor

Poka yoke uses 2 systems:__ a warning poka yoke and a controlling poka yoke__. Warning systems signal the operator to stop the process and fix the problem. Some common examples are alarms, dials, flickering LEDs, and color coding. Control systems automatically shut down the process when errors or irregularities occur. The human factor is eliminated here.

On the shop floor, 3 methods are used to practically implement poka yoke. These are:

  1. Contact method: Evaluate the product by checking its physical properties. By checking properties such as the product shape, size or color, errors can be detected. The corner missing from the SIM card verifies the position by contact. In turn, the height bar in parking lots is a warning poka yoke.
  2. Fixed value / dosage method: Get a notification or reminder when an action hasn’t been performed or a component hasn’t been used. For example, a pill box is a controlling poka yoke. A tool drawer where each tool has its fixed location is an example of a warning poka yoke that uses fixed value.
  3. Movement method: The execution of certain steps is mandatory before the procedure can continue. A controlling poka yoke from everyday life is the child safety on the cap of a medicine bottle. Parking sensors provide a warning if you get too close to an obstacle.

Ideal partners: Azumuta and poka yoke

Thanks to Azumuta’s digital work instructions, no step in the production process is skipped. Via Azumuta you plan systematic product checks. The checks are bundled into handy digital checklists so that no check is overlooked. This way errors are discovered immediately and costs remain to a minimum.

If the operator discovers an error, he can immediately provide feedback via Azumuta. Thus ensuring that, a solution can be found to avoid similar errors in the future.

Team leaders automatically receive notifications of problems.

All information and data from the shop floor is orderly displayed within Azumuta. This allows managers and supervisors to check the current state of the factory floor at a moments notice. That way, problems are quickly addressed and resolved. Azumuta also allows work instructions to be easily changed or updated to the latest version.

Operators can report errors immediately within Azumuta. Following a quick analysis, the cause of the problem can be remedied and after adjusting the digital work instructions or the work environment, similar errors will be avoided in the future. Taking you one step closer to zero-defects production.

Take the first step towards zero-defects today!

Connect your people, machines and systems and see how Azumuta can help avoid errors by digitizing your factory floor. 

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