crackedAccording to the USDA Egg Grading Manual,  “Checks [aka ‘cracks’] are an unavoidable problem in the marketing of eggs because eggs cannot be assembled, graded, packed, transported, and merchandized without some breakage. “   Unavoidable.  That’s the standard, I guess.   The grading manual does not cite a specific AQL for cracks, but clearly it implies some number above zero.   According to ISO standard 2859,  AQL, Acceptance Quality Limit, is the “quality level that is the worst tolerable.”   ‘Tolerable to whom?’ I ask.

Who buys eggs without opening them to check for cracks?  Because the industry has decided that cracks are ‘unavoidable’, we, the customers, routinely inspect for broken eggs.  Most persons I meet, outside of a few in purchasing or quality, have never even heard of AQL or the statistics behind it, but all are routinely subjected to its outcome.  I first became aware of AQL in an oblique fashion when I worked in an IT department attempting to implement MRP.  One of about two dozen order modifiers provided in our MRP software, AQL, was the means by which our buyers enabled suppliers to pass inspection for incoming material with defects.  If incoming material could not pass a 1% AQL, it might be tweaked to 1.5%.   We unfortunately decided that inspecting defective lots was sometimes  more tolerable than running out of parts.  After a time, it became our standard, just like checking for cracked eggs.

For the last decade, more or less, I’ve carried an egg carton with me to customers as a prop.  The message attached to the egg carton  is this:

“The only acceptable level of quality from the customer standpoint is zero defects.”

This fundamental principle behind Shigeo Shingo’s zero quality control became a turning point for me in my own understanding.  As customers we should not consider any other level ‘tolerable.’  Once I seriously adopted this principle as a customer, our suppliers became better suppliers  — and we, too, became a better supplier to our customers.

Restated from a supplier’s perspective we say “Never pass a defect.”  That’s the ideal condition for our customer.   To emphasize this thinking, I’ve returned once more to the carton of eggs with a short video vignette about passing defects.   It’s taken from a new GBMP DVD entitled True North In A Nutshell.  Have a laugh: .  (When was the last time you had egg on your face?   Share a story.)

We’ll release the True North DVD at our Northeast Shingo Conference in Hyannis, Massachusetts, September 24-25 … less than two weeks away!  Hope to see you there.


BTW:  My next free webinar, “Tea Time with the Toast Dude”, entitled Managing Up (click to sign up) is coming up next Tuesday, September 10 at 3:00 p.m.  I’ve had many requests to weigh in on this subject.  And one lucky participant will win a free registration to our Northeast Region Shingo Conference.

6 thoughts on “Cracked

  1. CJames

    Not only do I open the carton and take a look – I physically touch each egg (rocking it a little in it’s slot) – I do it to be sure the bottom hasn’t cracked – leaking egg which turns to glue. ie the egg moves it is ok………..the egg doesn’t move – it has a crack on the bottom. I will never forget going to the grocery store with my elementary school aged child – who thought I was counting the eggs and in a very exasperated voice -asked me one day why I counted the eggs – “mom, the carton says a dozen, that’s 12 – there’s always 12 eggs – so why do you always have to count them?”

  2. Jason Rekker

    Hi Bruce,

    I’m not sure I understand.

    You have no doubt come up against the problem where aiming for zero defects becomes cost prohibitive. The customer simply won’t pay for the additional resources required for perfection.

    In the case of eggs, I’d much rather quickly check for broken eggs than pay an extra $0.25 (to pull a number out of thin air) to be assured of perfection. No doubt the egg farmers know this, and thus have a tolerance level that achieves their goals.

    I have dealt with this personally, where I am a manager of a greenhouse & nursery operation. Plants have an inherently high level of variation, and with over 1,000 varieties, grown in multiple sizes, and with quality standards changing through the season, combined with high turnover and seasonal staff who receive minimal training, the problem of picking orders first time with zero defects has thus far eluded us. When we tried to get the order picking perfect at the first stage, our productivity plummeted. When there was NO quality control at the first stage, productivity also plummeted (because it bogged down the upstream process with errors). We found that a moderate error rate was tolerable for the time being and has so far resulted in the highest productivity, because going too far either way destabilized the process.

    In the meantime we’ve been working very hard at reducing the root causes of variation so that plants require less grading to begin with.

    So, isn’t it okay to tolerate a certain level of defects if the cost of preventing them is greater than the value generated?

    Love reading your posts, keep them coming!

    Jason Rekker

    St. Catharines, Ontario


    1. toastguy


      Thanks for your question.

      The point of my post is that ideal quality, from a customer standpoint, is zero defects — nothing more. While you may not yet be able to achieve the ideal condition, it remains the ideal. A customer may tolerate less than that, but this a slippery slope. How do we rationalize the tradeoffs? Of course, in my example we are only talking about the quality of a dozen eggs. (Actually, to digress, a gentlemen from the U.K. responded to me a while back, “We don’t have cracked eggs in England.” I never verified that:)

      But suppose we are talking about tradeoffs in an automobile. Consider the position taken by Ford in the mid-70’s regarding exploding gas tanks on its line of Pinto’s: “Ford found it cheaper to pay off the families of the victims of Pinto fires than the $137 million it would cost to fix the Pinto immediately, according to an internal Ford memo introduced during a civil trial. That meant it was not cost-effective to do the repairs.”

      This idea of zero defects is not new, but it’s hard to ‘unlearn” the deep-seated AQL thinking that defects are unavoidable. This is one reason why so many organizations fail to gain the full benefits of TPS.


  3. Dan

    Today I went to bring my own egg carton to work as my prop, and discovered goop from a cracked egg inside…keep inspecting.

  4. Pingback: Ten Posts for Ten Shingo Principles | Old Lean Dude

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