Lean and Elimination of QC Inspection Points in a New factory

[DRic41]

My new factory follows Lean principles wherever possible and as a consequence has removed some of the inspection steps within the various processes.

my problem is that mistakes are being passed onto the next stage because they're not being inspected.

I would add an inspection step in but that goes against (in my understanding) 'Lean'.

How would you fix it?

TIA

 

[Al Rosen]

My new factory follows Lean principles wherever possible and as a consequence has removed some of the inspection steps within the various processes.

my problem is that mistakes are being passed onto the next stage because they're not being inspected.

I would add an inspection step in but that goes against (in my understanding) 'Lean'.

How would you fix it?

TIA

Prevention! Find the root cause up stream.

 

[Golfman25]

What Al said -- why is the mistake there in the first place?

 

[Miner]

Source inspection (Shingo definition) and mistake proofing.

 

[Sidney Vianna]

I would add an inspection step in but that goes against (in my understanding) 'Lean'.

How is scrap, rework or repair lean? Obviously, it isn't. There is a fundamental misunderstanding at your organization of lean concepts. Avoiding reliance on inspection is a noble cause, but BEFORE doing that, you have to develop processes robust and capable enough that you can logically justify the elimination of unnecessary inspection points.

Eliminating inspection points by wishful thinking is just silly. You mentioned being in a new plant. Chances are, the workforce and the production process are still not mature enough.

 

[Bev D]

This categorization of inspection as waste is misinterpreted.
By definition in the Toyota Production System an din some versions of American "lean" inspection is a waste because if you made defect free parts inspection would not be necessary. defects are the root of all waste...

TPS also requires that all waste be minimized (realizing that while you never reach perfection you can reach a much better state by embarking on the process of waste elimination. So the watch word for inspection is that when defects are present it far better to inspect for them as early as possible to reduce the downstream waste especially on the Customer experience. the long term plan of course is to work to understand the cause of the defects and prevent them as well as design your products and processes to prevent defects. The mantra is to push any necessary waste as far upstream from the Customer as possible and as far away from the production operators as possible.

 

[Rajasekar]

In simple term, lean holds that waste is caused by additional steps, processes and features that a customer doesn't believe adds value and won't pay for. Please look into the removed inspection steps. does it add any value & refer PFMEA with control plan. Does our system enough to produce defect free component. Then remove the inspection steps. we did like it in our manufacturing process & achieved our target PPM.

 

[LeanGreene]

We have had similar issues here, sometimes you have to make a call if you're running a product that has a higher defect percentage, you may want to add for QC inspections.
1. Add your QC back in for short term.
2. Contact customer and really listen to the VOC ( we have found some defects are acceptable to customer and we were scrapping them).
3. Start your investigation into the defects by using the various tools.

 

[RCH2016]

Deming said to reduce RELIANCE on testing, not to eliminate it.

 

[Bill Levinson]

Source inspection (Shingo definition) and mistake proofing.

This is exactly what one does in lean. The Ford Motor Company, as I recall, said "Don't take it, don't make it, don't pass it along" with "it" referring to poor quality, and this is described in Shingo's book on Zero Quality Control. https://www.amazon.com/Zero-Quality-Control-Inspection-Poka-Yoke/dp/0915299070

"Don't take it" is achieved through source inspection. "Inspection" should ideally be automated because inspection by people is labor intensive and usually not 100% effective. The general rule is that it is about 80% effective.

"Don't make it" is achieved through poka-yoke or error proofing. This is automatic and, by definition, does not rely on worker vigilance. As an example, the jig or fixture prevents the part from being inserted backward.

"Don't pass it along" is achieved by outgoing inspection, which again should be totally automated. Shingo gave an example in which drill bits sometimes broke, and the part left the drill press without a hole in it. They installed a rod (which worked in concert with the drill) that was supposed to go through the part that just came out of the drill press. If it didn't, it meant there was no hole and the press would stop (autonomation or jidoka) so the workers could replace the drill bit. Although it didn't stop the generation of one defective part, the part never reached the downstream customer and was then re-drilled to make it into a good part.

While non-value-adding, this kind of "inspection" is still mandatory to protect the internal or external customer, and may in fact be part of the control plan for the process. Another way of saying this is that inspection is value-assisting, a useful term for activities that, while they do not add value directly to the product, are still useful because we would soon notice their absence if they were not useful. Non-value-adding, i.e. total waste, is characteristic of waiting and waste motion that do absolutely nothing to add value or assist in the addition of value.