Error Proofing Verification - Layered Audit Question

[qwert98]

I understand how error proofing stations work, but as part of a layered audit I need to verify my error proofing stations. I know how to verify with simple stations ie. make a bad part, insert into the error proofing station and verify that it fails.

The question is how do I verify a station makes a part live? I have a station sets a voltage on a part, and another one that welds to a certain value. I can't force the machine to make a bad part. How do I verify that these stations work? Are these stations that I really need to error proof?

Thanks for the help!

[BradM]

Hello, and welcome to the Cove!

As far as forcing error, I'm not sure what your part is, and whether Destructive Testing is an option.

However, I would submit to you that you can vary voltage and weld parameters. I'm not a welder, but have been around long enough to know there's a reason why you pay for a good welder. There are a lot of variables associated with welding. I would think those could be introduced.

[qwert98]

Thanks for the reply and the welcome!

I am looking how to verify an error proofing test in general where the test is part of a prcess. We have one automated process where a potentiometer is turned to a specific voltage. The error proofing is that the machine will fail a part if the specific voltage is not hit. I can't force it to hit the incorrect voltage (and therby fail the part), so I don't know how to verify that the station's error proofing is working.

I may not have to error proof these stations - I may be diving into this too deep...

[pondo]

Not enough info.

[BradM]

Originally Posted by qwert98

Thanks for the reply and the welcome!

I am looking how to verify an error proofing test in general where the test is part of a prcess. We have one automated process where a potentiometer is turned to a specific voltage. The error proofing is that the machine will fail a part if the specific voltage is not hit. I can't force it to hit the incorrect voltage (and therby fail the part), so I don't know how to verify that the station's error proofing is working.

If you have a potentiometer to dial in the voltage, why can't you vary the voltage? I'm just confused, I guess. If you know that incorrect voltage can fail the part, then adjust it and fail the part. By varying the voltage, you can determine what the acceptable range is.


Every process has error; one just needs to figure out how to identify it, measure it, and make decisions if it is worth controlling.

[AndyN]

How about this.

If that part of the process is 'off' will the line still cycle and process the part to the next position. Error proofing may not be variations of voltage etc., it could just mean the (weld) cycle is skipped and not noticed.

[Helmut Jilling]

Originally Posted by AndyN

How about this.

If that part of the process is 'off' will the line still cycle and process the part to the next position. Error proofing may not be variations of voltage etc., it could just mean the (weld) cycle is skipped and not noticed.

...simple is better...I agree....

[vanputten]

How is verifying a bad part was made "error proofing?" You have not prevented any error. Error proofing prevents errors from happening. Detecting errors already made, in my opinoin, in not error proofing. That might be escape proofing but for sure not error proofing.

In welding, a common error proofing methodology is to create assembly jigs that only allow parts to be welded together in one orientation.

If the electrical system on the welder stop the welder from making a bad part, that may be error proofing.

Regards,

Dirk