Inspection: is it a necessary evil? That’s always a good opening line to get the debate going, but one thing is for sure: it is waste!
When I tell plant managers that their reliance on Inspection is a cause for some of their self-inflicted muda, nine times out of 10 they look at me like I have three heads. How on earth, they argue, could Inspection be wasteful? Isn't Inspection where waste gets caught and eliminated?
Pause and think about that statement for a moment…paying people to check other people’s work? Moving product to inspect it (conveyance waste) and holding product to inspect it (wasted time and tied-up inventory) don’t sound like very healthy business practices to me.
Our goal with lean is to build processes (not necessarily human-dependent) for checking for defects. This could involve enhancing our quality assurance (QA) capability within the process itself (using andons, for instance) or applying automated checking applications, if funding allows. The bottom line is, the more we rely on human dependability in Inspection, the more defects are likely to slip through the cracks.
It's built-in quality that is the key to eliminating waste as a consequence of having to have Inspection. And it should be in the form of error-proofing and poka-yoke devices – when we accomplish that we create the robust, right-the-first-time processes we need to make defect-free products
My new sketch and animation video explain more about the waste in Inspection. Once you've reviewed them, I ask you to think about how you have your processes set up…have you fully grasped error-proofing opportunities? Do you provide your employees with the means to call for help to stop defects being passed downstream?
Maybe it’s time to re-think your current approach…
Dave LaHote, Dave Logozzo & Ernie Richardson
Ernie Richardson & Tracey Richardson
By Jim Womack
By Mike Rother and John Shook
Could the airplane be designed such that the human inspection would not need to occur? Have older airplane designs had potential failures that no longer exist in new airplanes?
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There is a certain degree of inspection that is necessary, but I think the point is to build quality into the production system so you don't RELY on inspection.
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Fantastic animation, very well done.
I agree with Ken's statement. Tolerance for failure varies by customer needs. If I buy a notebook of 8.5 x 11 paper, I don't mind if it is "off" by .2 inches, or has a few missing (or extra) sheets of paper.
However, if I'm flying an airplane (or using some other product that can cause my demise if it fails), I'm comfortable paying for the added inspection steps. I do understand that it is wasteful by having employee #2 inspect what employee #1 just worked on... But an inspector sometimes has a "bigger picture" systems view that can find things that an individual employee can't.
Either way, it is a healthy debate. In a perfect world it wouldn't be an issue!
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Maatje, my previous employer was a major hospital system. They also had a lot of legal compliance concerns, as well as compliance for various certifications. The result was a lot of "business value added" activity.
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It is interesting to observe that many industries are still requiring to mature and include the concept of different levels of Mistake Proofing within their DNA.
I have personally experienced the push back from teams who assemble medical equipment to implement Mistake Proofing to ensure that controls ensure Prevention and Elimination of defects but due to getting the whole process recertified from customer (which could take long time before a product could be shipped due to change of process after implementing Error Proofing).
I completely agree Inspection is TOTAL waste, but how does one move the cheese in industries that have yet to embrace the concept?
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There will almost always be some "necessary" quality inspections. The trick is deciding what is absolutely necessary and what is not, then the frequency of the inspections, what R&R work has been done to ensure that only the minimum amount inspections are carried.
I have a toolshop manager here in China who over inspects everything multiple times, it's very much a case of who guards the guards, who guard the guards, that guard the guards.
Slowly bringing him around, but even though he can see it's waste and is costing him (and us) time and money it's deeply ingrained and takes more time than I would like.
Dave LaHote, Dave Logozzo & Ernie Richardson
Ernie Richardson & Tracey Richardson
By Jim Womack
By Mike Rother and John Shook
In our industry we have inspections that MUST take place or the airplane doesn't fly. We call that "Non value added but necessary".
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