Poka-yoke is a Japanese term that means “mistake-proofing” or “error-proofing”. Simply put, poka-yokes are mechanisms that make errors visible or, in their most advanced form, impossible to do. The world is full of poka-yokes, some designed on purpose, some not.
You can find one example in the picture. A broken subway turnstile with a sticker that a) tells everybody that the mechanism is broken, and therefore, not ready to use and b) prevents any customer from putting the subway ticket in the slot (what will have unexpected consequences)
People who don’t take risks generally make about two big mistakes a year. People who do take risks generally make about two big mistakes a year.
One of the basic concepts of PDCA (Plan-Do-Check-Act) is that you should plan your improvement work before you actually start doing it. In many cases taking baseline data, talking to experts and, of course, going to the gemba is needed for a good “plan” phase.
But unfortunately some people stop here and data is taken as if having a check sheet or an excel file is enough. It is NOT. The plan phase has to be done looking for subsequent action. In other words, get the data you need to move to action in a meaningful way with a controlled level of risk.
Two notes on this:
- “Meaningful” does not mean “be sure that you will be right”. It means “be sure that you’ll learn something”. Don’t do useless tests just because you forgot to measure a critical parameter. Sometimes you are lucky enough to prove the root cause of your problem. Hurrah! But proving some hypothesis wrong can be even more important.
- Every change has a certain level of risk. There is not such a thing as “no risk”. I’m serious. The good thing (?) is that doing nothing can be even more risky. Not being scared of trying (controlling risk, of course) is key. Creating an environment for safe testing is fundamental.
Once the Plan-Do is done, it’s time to Check and Adjust as needed!
Plans are nothing; planning is everything.
Dwight D. Eisenhower
Standards are just like plans, their power is not in their existence (they are, of course, fundamental to reduce variability and great tools for training, but this is another story). A standard work sheet by itself means nothing. It will not improve anything. However, standardizing is critical because it forces you to think what is the best way of doing the work. Then it helps identify when something in the process is not working as it should; they set a baseline to make problems visible. A process without a standard is very difficult (impossible?) to improve. If anything is valid, how will you know if things are going wrong? Standards are the keystone for continuous improvement.
Standards are nothing, standardizing is everything.
P.D. If after reading this post you still agree with the message on the mug , you can buy it here:
One of the best ways of applying lean is using the simplest solution possible. In these days it looks that IT and automation must be part of the perfect solution, but it’s not always the case. In this brand new modern restaurant they have decided to use a simple system to link customer-table-food. Nice, visual and cheap.
Don’t take me wrong, I have nothing against computers, they are powerful and make our life better. However sometimes they make the process objectively worse: more complicated, difficult to use, difficult to learn, information is hidden, problems are difficult and expensive to solve. And all that is waste.