Seeking examples - Error-Proofing Methodology - Used with regard to corrective action

[Lewis]

I am in need of assistance! Could someone please provide some examples of "error-proofing methods" used with regard to corrective actions?

We've undergone an internal audit to the TS standard and had a finding written against paragraph 8.5.2.2. Basically, the finding stated that we had not incorporated error-proofing into our corrective actions. I disagree with the finding because for each corrective action, we address what is being done to correct the problem and we also address what we're going to do to keep the problem from recurring. I contend that the activity performed to prevent the recurrence of a problem is a form of error-proofing.
Am I correct in my interpretation? Any guidance would be greatly appreciated.

 

[D.Scott]

You may be partially correct. It depends on the corrective action.

Let's say you have an assembly problem where the operator is putting a component on upside down. You re-train everybody and add an inspector to the end of the line to ensure zero defects get through. The corrective action proves to be 100% effective for the validation period and the corrective action is closed.

You haven't error proofed the nonconformance. The assembly can still be made incorrectly. If you had redesigned the part so it only fits one way, it would be impossible to assemble it upside down.

Both approaches may have worked but the error proofing, once done, eliminates the need for an extra inspector - cost savings. It isn't always possible to use error proofing but you should be able to show instances where it was used - or at least considered. There are hundreds of examples of error proofing and I'm sure you will find a lot with a search here. If you would share the N/C and something about the process, I am sure there are many here who would be willing to make a suggestion.

Dave

 

[Kevin H]

Error Proofing isn't 100%

Dave, I agree with your exposition 100%, but my real life experience shows that "the can't fit/be assembeled that way" isn't a 100% answer. I spent about 8 years working in the industrial gas industry for one of the major industrial gas suppliers. One of the error-proofing set-ups for industrial gas use was to have different threads for regulators designed for use with fuel gases, versus those designed for use with oxygen service. You can't cross use, unless you really, really work at it - machining your own adapters, jury rigging adapters, etc. Yet, at least once a year the company I worked for published a horror story of one of our customers having done exactly what was described above. If the customer was lucky, we caught them and shut them down by refusing to deliver until the situation was corrected. If the customer was unlucky, we stopped delivery because we were helping them with an accident investigation.

Humans can be amazingly inventive, when they are determined to do something, even to the point of defeating all reasonable attempts to assure something can be assembled only one way.

 

[Marc]

Don't forget... Error Proofing and Poka Yoke Techniques for some thoughts...

 

[Lewis]

The N/C actually had two parts to it:
First, the standard states that error-proofing methods shall be used in the corrective action process. The wording in our procedure was "The corrective action process will include error-proofing methods, where appropriate." The auditor had a problem with the term "where appropriate" versus the "shall" in the standard.
I reviewed the IATF Guidance to ISO/TS 16949:2002 and it states that the utilization of error-proofing methodology should be generally utilized wherever cost-effective and feasible. This implies that error-proofing methods do not necessarily need to be applied to all corrective actions. Only those for which it is cost-effective and feasible. Thus the term "where apropriate".

Second, the N/C stated that there was no evidence of error-proofing on existing corrective actions. An example of a problem area would be the packaging of precision metal stampings. We may receive a customer complaint for some minor damage to the part that obviously occurred during transportation. What would be an appropriate error-proofing method for this type of problem? We could beef-up the packaging, but that would be somewhat cost-prohibitive. Maybe we just need to document this suggestion in the corrective action response and let the customer make the decision on whether they want to pay for the increased packaging cost.

Sorry for the rambling! I just need some direction so that I can train my complaint response team on this issue. Feedback is requested!

 

[Marc]

In your document, change "...when appropriate..." to "...error-proofing shall be used where it is cost-effective and feasible...".

 

[Lewis]

Don't forget... Error Proofing and Poka Yoke Techniques for some thoughts...

Thanks! This helps!

 

[Lewis]

In your document, change "...when appropriate..." to "...error-proofing shall be used where it is cost-effective and feasible...".

I had thought about that, but I had a minor dilemma. Who can make the determination on whether it is "cost-effective and feasible"? Our organization, or the customer?

 

[Marc]

Error proofing is not a requirement per se, but it is a requirement to consider / investigate error proofing options (opportunities, whatever...).

As an added thought, my consideration of solving a problem is the extent, frequency and effects. If something only happens once a year I doubt I'd consider error proofing. But even here - it is important to consider the impact of that 1 occurrance. Having a pacemaker damaged in transit in such a way that the damage is not evident and it could be implanted might make the company consider error proofing whatever is was that happened. Yet even here - the first question is can root cause be determined?

 

[Marc]

I had thought about that, but I had a minor dilemma. Who can make the determination on whether it is "cost-effective and feasible"? Our organization, or the customer?

Your organization. That's not to say that your customer will agree with you if they get a copy of the corrective action. That's when negotiations start.