Poka-yoke is a Japanese quality control technique developed by former Toyota engineer Shigeo Shingo. Translated as “mistake-proofing”, poka-yoke aims to prevent defects in the manufacturing process that are the result of human error. Poka-yoke is a lean manufacturing technique that ensures that the right conditions exist before a step in the process is executed. This makes it a preventative form of quality control since errors are detected and then rectified before they occur.
Some process errors cannot be detected ahead of time. In this case, the poka-yoke technique seeks to eliminate errors as early on in the process as is feasible.
Although the poka-yoke technique became a key part of Toyota’s manufacturing process, it can be applied to any industry or indeed any situation where there is potential for human error.
One of the most well-known examples of poka-yoke in action is in the case of a manual automobile. The driver must engage the clutch (a process step) before changing gears. This prevents unintended movement of the car and reduces wear on the engine and gearbox.
Another example can be found in washing machines, which do not operate if the door isn’t closed properly to prevent flooding. In both cases, poka-yoke principles mean that automation is in place to prevent errors before they occur.
The six principles of poka-yoke
To reduce the prevalence of process errors, poka-yoke is based on six principles in decreasing order of effectiveness.
- Elimination – the most preferable solution. It involves redesigning a product or process so that a particular step is no longer necessary.
- Prevention – or engineering a product or service so that it is virtually impossible for an individual to make a mistake.
- Replacement – can a more reliable process be substituted in to lessen the chances of an error occurring?
- Facilitation – or the adoption of techniques to make a task easier to perform. This may involve combining certain steps.
- Detection – or identifying an error before further process steps are undertaken. This allows the error to be rectified without further damage to equipment or personnel.
- Mitigation – the least preferable solution. Here, the aim is to minimize the effects of errors without necessarily solving them.
Benefits of poka-yoke principles for businesses
Error prevention is an obvious advantage to poka-yoke, but what positive ramifications does error prevention have for business?
Errors on production lines decrease profitability – whether that be through line shutdowns or expensive worker injuries. But poka-yoke principles improve a company’s bottom line in other ways.
For example, hotels now require that guests insert their key-card into a slot to activate electricity in their room. Since many guests do not bother to turn the lights off after they leave, the hotel can save money on wasted electricity consumption.
Preventing errors before they occur increases productivity. Online forms require that every field be filled out before submission. This reduces errors in forms resulting from incomplete or missing information, saving the company time and money in having to chase up consumers for the extra details.
ATMs also chime or flash to remind the customer to retrieve their debit card and cash. This greatly reduces the once common error of customers leaving their cards in the machine. It also saves the bank money in loss prevention, giving customer support the resources to deal with other problems.
Simplification of smaller, error-prone tasks
Small tasks with high probability of error are particularly prevalent in some industries such as the service and hospitality industries. Cashier errors in counting change, for example, are relatively inconsequential errors in isolation that have the potential to lose a business a lot of money over the long term.
To this end, poka-yoke principles have automated the change counting process and where automation is not possible, digital interfaces verify that the cashier has given the correct amount of change. Similar systems are now in place to prevent errors in order fulfillment and delivery of orders to a table.
- Poka-yoke is a Japanese quality control technique that aims to make processes error-proof.
- Although having origins in the manufacturing industry, poka-yoke principles are useful in any scenario where there is potential for human error.
- Poka-yoke error prevention is guided by six principles, with elimination the most desirable and mitigation the least desirable. All six principles can nevertheless improve productivity, profitability, and simplify smaller, error-prone manual tasks.
Other strategy frameworks:
- AIDA Model
- Ansoff Matrix
- Balanced Scorecard
- BCG Matrix
- Design Thinking
- Lean Startup Canvas
- Pestel Analysis
- Technology Adoption Curve
- Total Addressable Market