Nothing Hokey About Poka Yoke

gombadmin Blog

by Scott Baird, Operational Excellence Consultant

I had just finished my delicious burger and fries and was heading out the door to my next appointment. Being the ever-gracious patron that I am, I picked up my tray, wrappers, cup, and used ketchup packages and headed out. Without thinking, I dropped everything—including my TRAY—into the garbage can.

About two steps out the door, my brain caught up with my actions and I stopped in my tracks—paralyzed after realizing my mistake and wondering what to do. Do I go back inside and fish the tray out of the garbage can? Do I tell the store manager? The ever-gracious patron was long gone and I took off as quickly as possible hoping not to be noticed.

While the impact of my one lost tray may not be significant, the cost of thousands or even millions of trays being thrown away at fast food chains across the globe would be sizable. Fed up with the loss of trays, fast food chains began looking for answers. They couldn’t get rid of their customers, or trays, or garbage cans, but they could remove the opportunity for error, and thus sprouted the invention of the round cover over the garbage can that rectangular trays do not fit through. By simply changing the shape of the garbage can opening they removed the opportunity for discarded trays.

This process of removing opportunities for human error is often identified in Lean Six Sigma communities with the Japanese term Poka Yoke, which roughly translates to mistake proofing. You have likely experienced this process in other areas. Think about the number of times you tried to submit an online form, only to be denied because you failed to fill out a “required” information box. Other examples of mistake proofing include, the auto shut off on your iron, the overflow drain in your sink, the dryer or microwave stopping once the door is opened, and the list goes on.

In government, we too are impacted by human error in the work we do. Most of us provide services and interact with the public on a regular basis. Any time people are involved in a process; there is the chance for error. We are, after all, human and will not be “perfect” all the time. However, as State of Utah employees, we should strive to serve our customers to the best of our ability and, in some instances, assist them in avoiding their own human mistakes.

The American Society for Quality (ASQ) lists several instances where opportunities for mistake proofing may be found:

  • Process steps where human error can cause mistakes or defects to occur—especially in processes that rely on the worker’s attention, skill, or experience
  • Service processes where customer error affects output
  • The hand-off step in a process when output or the customer (for service processes) is transferred to another worker
  • When a minor error early in the process causes major problems later in the process
  • When the consequences of an error are expensive or dangerous

As mentioned in the title, there is nothing hokey about Poka Yoke. Regardless of our agency, division, or job position, there is likely some aspect of work that allows for human error and thus provides an opportunity for mistake proofing. Real savings and value can be delivered to our customers as we strive to apply the principles of mistake proofing to our efforts of continual process improvement.

You can find more information on improvement principles and tools by visiting the Operational Excellence section of