Taiichi Ohno

Words of Taiichi Ohno Sensei, Part 1: “I Never Said There Were 7 Types of Waste”

By Jon Miller Updated on January 3rd, 2022

One has to be careful these days when making statements about the origins of TPS and check the facts, or else be pinned to the mat for a count of three by the investigative tag-team of Art Smalley and Isao Kato. So I’ll confess to a terrible truth of Lean manufacturing that I’ve known about, but only for a short time: Taiichi Ohno never said there were 7 types of waste.

Kaizen consultant and author Yoshiya Ito was a journalist when he was younger, and knew Mr. Ohno. On his website Ito shares his memories of Mr. Ohno and words that he spoke. In a section called Words of Taiichi Ohno Sensei, Ito credits his teacher with the following:

“I don’t know who came up with it but people often talk about ‘the 7 types of waste’. This might have started when the book came out, but waste is not limited to 7 types. There’s an old expression “He without bad habits has seven” meaning even if you think there’s no waste you will find at least 7 types. So I came up with overproduction, waiting, etc. but that doesn’t mean there are only 7 types. So don’t bother thinking about ‘what type of waste is this?’ just get on with it and do kaizen.”

Wow. At this point it’s tempting to follow Mr. Ohno’s advice, give up thinking and writing about the 7 types of waste and TPS and just do kaizen. If I suddenly give up blogging, you’ll know why.

Mr. Ohno was known for making shocking statements. One of the other gems Ito attributes to Ohno was “Just because it says so in a book doesn’t mean I said it.”

So who did arrive at the number seven and codify the 7 types of waste? My guess is the managers at Toyota who in 1973 wrote down the Toyota Production System ideas and philosophy that was in the air. Perhaps on his next trip to Japan this summer the Green Hornet* (a.k.a. Art Smalley) can find out more about who actually coined the 7 types of waste if it was not Taiichi Ohno.

Bonus Section: 5S Contains 25% More S than You Need

While we’re shattering myths of Lean manufacturing… do you think there are actually 5S in the Toyota Production System? There aren’t. There are 4S, the first four. Who needs self-discipline if you do the first four properly? In some smart Japanese companies I have seen 3S, where they drop seiketsu which is literally “cleanliness” as in “spic and span” or “wash your hands with soap”. Who needs that if you Sweep properly. Originally 5S was seiri seiton which means “tidy up the place”. But 2S was too simple to make a book that sells.

The real reason we have 5S in the Lean manufacturing lexicon instead of 4S is that Hiroyuki Hirano wrote a book on 5S that was translated into English. Had a Toyota person written about workplace organization we would be calling it 4S. Just because it says so in a book doesn’t mean it’s the truth.

Kaizen. Read about it, think about it but most important, do it.

*For those of you who are not familiar with the Green Hornet, he is an American comic book hero and crime-fighting newspaper owner.

  1. Davod Ebrahimi

    July 11, 2006 - 3:19 am

    great! more types of waste? huh! i read an article in an International IE congress in Iran last year, about a new type of waste: “Knowledge waste”. have you heard about it? it was interesting for me. it’s about the knowledge lost when someone goes out of the organization. documenting of knowledges and know-hows is the first solvation. do you know abother way?

  2. Chris Nicholls

    July 11, 2006 - 4:35 am

    I’d like to say I’ve been reading your blog with interest for about 3 months following a tip-off about its existance from one of my Japanese collegues.
    I find the issues raised very refreshing and practical.
    However this is the first time I’ve been moved to comment.
    The points you make about just getting on and doing kaizen are very valid, I am a firm believer in JDI.
    The debate about the ideal number of categories of waste, I don’t think its important how many categories of waste there are. At Ricoh in Telford UK we added one more “Underutilisation of People” making 8 wastes. But in other Ricoh subsidiaries they have up to 12 wastes listed.
    Those original most frequently mentioned 7 original wastes are themselves now sub-divided.
    For example “Motion” has been categorised further into 12 wastes of motion in the guidelines of the Ricoh Production System.
    When I first joined Ricoh in 1984 we had 3S as our guiding principle and foundation for improving our factory this has since grown to include the other 2 S’s, its just like fashion everyone likes the latest. I believe that some organisations are even advocating 7S now, but I can’t think what a further 2 more S’s can bring but more complication.
    I believe in KISS ……. “Keep it simple, stupid”. All the most effective improvements at Ricoh have been dead simple.
    I have got great inspiration from your commentry on the Chapters of Mr Ohno’s book Gemba Keiei, please keep the comments and interpretations coming.
    Very Best Regards & Thanks
    Chris Nicholls at Ricoh in the UK.

  3. B. Huff

    July 11, 2006 - 6:11 am

    Thanks Jon, It would be really great if someone could translate more of what Onosan actually said in Japanese to English. I have read the three English Books, but there is a lot more in Japanese. It might help everyone’s understanding to hear more of what he actually said.

  4. Venkatesh

    July 13, 2006 - 10:28 am

    The seven types of wastes were also documented by yet another TPS sensei Suzaki Kiyoshi.
    As a matter of fact these are known as Suzaki’s seven wastes in many Lean circles.
    Suzaki’s ’87 book The New Manufacturing Challenge is a good read.

  5. Mark Jaeger

    July 13, 2006 - 7:52 pm

    Jon says, “While we’re shattering myths of Lean manufacturing… do you think there are actually 5S in the Toyota Production System? There aren’t. There are 4S, the first four. Who needs self-discipline if you do the first four properly?” In my time with Toyota, we practiced 4S, but it was “spic and span” that we omitted.

  6. Jon Miller

    July 16, 2006 - 8:21 pm

    Thanks for your comment Mark. It shows that what’s important is not so much how many S there are or what they are called but the underlying thought and behavior that is TPS.

  7. Michel Baudin

    July 18, 2006 - 11:37 am

    The number of elements in a list has to do with national culture. Japanese lists tend to have seven elements: the 7 tools of QC, the NEW 7 tools of QC, the 7 steps of automation, etc.
    On the other hand, since 4 (“shi”) sounds like “death,” that number is avoided and many buildings in Japan don’t have 4th floors. Maybe that is why 4S became 5S…
    The magic number in this culture in 10, as in the ten commandments or the 10 articles in the bill of rights, and 13 is avoided.
    These choices don’t always have to do with content.
    Best regards.

  8. David McGiverin

    September 3, 2006 - 9:51 am

    I guess I’ve never read or heard that there was a limit to the numbers of wastes, or that Ohno had anything to do with labeling them. Anybody with a brain knows of these wastes before being taught that they have been named by somebody. I do know the 7 very well but when originally taught about the wastes I seen a list of hundreds. Hirano’s manual shows a very large list.

  9. Louis (newbie to lean)

    December 6, 2006 - 1:48 am

    Since we’re on numbers, someone forgot to mention 7 days of the week (or of Creation)… either way your blog is very witty *and* very informative! Keep up the great work.

  10. Harish

    January 28, 2009 - 4:34 am

    Greetings Mr. Miller,
    I have been reading your archives and came up on this. I have a quick question about 5S (4S)?
    Traditionally (Hirano or Ohno’s Work Place Management) 5S is in a specific order – Sort, Set (Straighten), Shine (Spic & Span), Standardize and Sustain (if needed). I have seen a few books and even a DVD (5S Garage) where the order was altered to Sort, Shine, Set, Standardize and Sustain. Any comments on this? Which makes more sense? Why would people alter the order and still call it 5S instead of My Version of 5S?

  11. Rokibul Islam

    April 30, 2021 - 3:36 am

    Great article indeed, thank you so much.

    Now a days people are more likely to be a differentiator!
    That’s why many people publish diluted/ modified information adding some unnecessary things with original one!

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