Saturday, January 19, 2013

Redundant Quality Tests & Inspections: The #Lean Waste of Overprocessing!

 A friend of mine, Bill Neale, Plant Manager at Radiall, (New Haven, CT) has a very interesting perspective on redundant quality tests and "inspections". Why is it that people very seldom get pulled over on the highway for weaving or tailgating? Yet thousands of people get ticketed every day for speeding? And yet weaving and tailgating probably cause as many or more accidents as speeding. But, there is no tool to measure weaving or tailgating. Speeding is supported by real data that usually holds up in court. You can put numbers to it. 

So, how much of the redundant testing and inspection we do is due to the fact that we have the fancy, expensive instrumentation or meter? Many of us heard during our Lean basic training that if the only tool you have is a hammer, everything looks like a nail. Is it heresy to go to Gemba and ask why are we doing all of this testing or inspecting?  I like to think of unnecessary inspection/testing as the waste of overprocessing. (that's the one where you go way beyond what the customer needs, wants or  is willing to pay for).  Can we AT LEAST ASK WHY? If there hasn't been a defect detected or a failure found in years, stop testing! If the supplier already tests it, stop testing! If you do it just because your quality system says to, change it! Sometimes, a required, unneeded test is done because of some catastrophic event that happened decades earlier. (Is a new non-value added test or inspection really the best countermeasure?) If a human needs to go find someone to sign-off (sometimes without even looking at it), then eliminate it. The worst kind of overprocessing is when someone else "over rides" the test result, and says, "no, that's OK, ship it!". In the words of Homer Simpson, dohhhhh!

Our endless journey toward flow is not about finding shortcut after shortcut in our processes. The whole point of approaching flow is how visible and "out of place" a defect becomes. It's all that inventory, motion, waiting, transport, etc. that hides problems. I have seen so much done in the name of "quality" and "safety" that has zero impact on either. All I'm suggesting is to ask "why"! 


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  2. I couldn't agree more! I have come across so many 'required' inspection processes that call for extra steps that were put in place 10+ years ago because of one instance of part failure. A lot of other factors have changed over the years as well. Is the part even produced the exact same way as it was back then? Same material? Same machinery? Maybe at some point the process was tweeked slightly and eliminated the need for an extra inspect step. It's at least worth taking a look into it!

  3. Thank you for that Ashley & thank you for reading my drivel!

  4. Great points. But "Stop Testing" can have risks. The fact that you have not had a defect in a long period of time needs to be considered in relation to the damage that would be done if it re-occurred. Would you want a food plant to stop testing for e.coli just because they had not had a positive for a long period. Risk analysis, frequency of defects, and cost of the test should all be factored into determining test frequency.