Here’s a news story about career day at a High School and someone talking about Lean (I guess Wahl, the clipper company, is using Lean):
“‘Poka yoke … allows you to dummy-proof something to guarantee your success’ and ‘Takt time’ is when a company makes only enough product to fill its orders. The new language is part of a Japanese-inspired, lean manufacturing philosophy that helps companies produce products with the least amount of labor, equipment, materials and power – ‘so, you’re working smarter, not harder,’ Segura said.”
I’ll nitpick (because I can) about the Poka yoke definition. I really dislike the phrase “dummy proof” or “fool proof.” There’s another Japanese phrase, “Baka Yoke,” I believe, that translates to dummy proof. Poka yoke means mistake proof… a less judgmental phrase. Maybe this is urban legend, but there’s a story about how Ohno (or Shingo) used the phrase “dummy proof” and somebody started crying at the factory, so they moved to error proof.
But, the phrase “Baka Yoke” is still in Ohno’s book Toyota Production System: Beyond Large-Scale Production. Does anyone have a better recollection of the history?
Either way, I think the phrase “dummy proof” misses the point, and ranks low on the “respect for people” scale. Errors aren’t made because people are dummies, or because they don’t care. The system made it too easy for an error to occur, that’s the assumption we have to go by, so solutions are most often with the system. This is different than Western management, which typically points the finger of blame first.
Update: Corrected “bakta” to “baka” per comments. I’ve seen it both ways in print, but will assume baka yoke is correct since it’s spelled that way in the Ohno book.
Thanks for reading! I’d love to hear your thoughts. Please scroll down to post a comment. Click here to receive posts via email.
Now Available – The updated, expanded, and revised 3rd Edition of Mark Graban’s Shingo Research Award-Winning Book Lean Hospitals: Improving Quality, Patient Safety, and Employee Engagement. You can buy the book today, including signed copies from the author.