Inspection Process Optimization

Hi bill C,
In your case, it would seem that your process depend on operators for the checking of parts. So a way to make your process more capable is to have more training for the inspectors.
Other than more training for the operators, u can also standardize the way that a part is being inspected.
 
tcm

Bill C,
Why on earth would you exclude a gage or MSA study? To me that is where you need to start. The outcomes of that will tell where to go next.
Regards,
Dr. Scott

Hmmm . . . . is it just me, or does this sound like the Red Beads Experiment in real life?  If one more layer of inspectors is good, why not add two or three more layers, just ot make sure we catch them all?  In fact, adding layers of inspection only worsens the problem, robs the process worker of ownership for the quality of the products they make, and increases the costs of goods sold for no real benefit.  I agree with Doc – do the MSA and find out where the problem is.  Then solve it – or better yet, remove the reasons for the defects.  Hey, now there’s a unique thought – improve the process!

Bill,
Do you check after each step of the process or at the end of the process?
If you check at each step of the process, can you use automation?
If you check at the end of the process, can you re-design your process as a single-flow line?
If you can check after each step, can you collect or create some material or components with defects for a non-conforming materials library.
Once you have your own standards you can test the accuracy and repeatability of each operator as the gentleman suggested.
Once you detect defects, you should stop your production line and investigate the true cause until the production manager comes down from his office, kicks you butt, and tells you you’re only an engineer. You can then find a better paid job selling Toyota cars.
Aurum

Bill,
If you know you are missing some defects in the inspection process, do you know which ones are slipping through?  Are there any trends? This may be able to help you focus your improvement efforts.  With this information, you may also look back upstream rather than at the inspection stage, to see if you can mistake proof those errors or at least catch them earlier on.
Hope this helps,
Patch

I would pareto which failures you are seeing.  Which characteristics are causing you the most problem.  Once identified, you can start your improvement activities.  Why is it a problem?  Is it operator dependant?  Wrong tooling or gauging?  This is where MSAs can help you out.  Lots of times the Blue print dimensions are not being interpreted correctly.  In our facility we have several very old drawings, as well as new drawings, resulting in different GD&T standards over the years.  Are all the operators in agreement of what the different GD&T standards are and how it affects their measurements and interpretations?
You could also look at which of the characteristics are critical or key and really focus on them.  A lot of dimensions are lots of times not as critical as others.  
 

In theory perhaps, in reality when you inspect twice AOQL goes DOWN because human nature ASSUMES the other guy will catch it.  (Actually I have overcome this by CAREFULLY designing incentive payments which reward re-inspection at the cost of inspection!)  More effective is employing two inspectors and dividing the area of accountability in half.

Make inspection more effective …There are lots of answers as how to improve the inspection process
but … you should focus also on …
– eliminating inspection as it’s non-value addedAlternative proactive approaches include product re-design,
process automation etc etcSix sigma projects are successful if you do not have to keep baby
sitting them – by “tactically” improving the inspection process you
are doing just that.My alternative 2c worth.Adam

Thank you, Bill.
 
You may want to consider some of the following ideas.
 
Is this assembly problem related to care and attention of the operators? Then a photo gallery of defects may be useful. May be even a side-by-side comparison between a good (excellent) and a bad (absolutely worse) product or assembly step. This helps people to understand, to learn and to talk about it.
 
Did you consider talking to the operators? Many times they have enough observations, summaries of the situation or suggestions for improvement.
 
Did you consider poka-yoke, i.e. fool-proof assembly? This way you’d allow only one way to do it either by design or tools used at assembly. Operators report they now can think about quality rather than doing the assembly right (it can’t go wrong).
 
Can operators down the line recognize assembly faults done earlier? If so I still like the Toyota idea, where they encouraged doing a total belt-stop when recognizing a failure. It hardly performs in the beginning, but helps to spot trouble and sources of trouble in real-time. May be you can try this on one assembly line? If so, be sure to provide support for the nasty remarks to come – and to deal with people being envy on achievements.
 
I like FMEA, but it’s shortcoming is related to our own imagination (what we think can or can’t happen). Even worse, I’ve seen too many FMEA’s mixing freely cause and effect and elaborating minor issues. There’s a better analysis tool available today, which helps you to focus and to reveal all known, all hidden and all available failure modes (seen or unseen) in your assembly process. Engineers think the process does something, while parts simply obey the laws of physics and the specific conditions met.
 
If you want to know more about this FMEA++ method or would like to have a contact in the US please let me know (by posting your email address in a reply to this post).
 
To me it sounds like the product design itself might benefit from an update. The way it’s designed and assembled today seems to leave room for trouble: it seems to be too sensitive to, e.g., operators concentration, may be variability of parts and compounds etc., perhaps even to customers usage conditions. This would call for a DoE, and, if you want to achieve extraordinary results, even a Taguchi DoE.
 
Hope this helps.
 
If you’d like more, please let me know.
 
Kind regards, Michael Schlueter

AlexanderSO,
How do you think Toyota improve their processes after their autonomous inspection find defects and they stop the line?
What you seem to be advocating is the use of American TQM model, which eliminates checking and attempts to assure quality solely through the statistical approach. This implies the customers have to endure defective parts until you identify the sources of variation and eliminate them!
This in essence is what is wrong with the American Quality approach and why companies like Ford are now trying to implement the Toyota Production System.
Regards,
Ford-guy

With respect you do not seem to understand the Deming cycle and the principle of single-flow. You should not inspect at the end of the line or at a “problem stage” using extra muscle! Each step should check the work of the previous step, by whatever means.
 
 
 
 
 

Good point Stan …
If you still buy domestic products out of loyalty to your community, you ought to understand irony.

R/sir
This is hanmanth Patil from India . i wish u would like to inform that
i need some information in like
SPC, TQM, FMEA,PPAP,CP,CPK, DFMEA,KAIZAN MATHOD,5S& HOUSE KEEPING , 7QC TOOLS , APQP,
where is using the thease mathod & I need Quality Control Process & systems
 
Thanking you
Regards
hanmanth patil