I was asked to help on a CI. So, I figured this was the best place to start. We are in the plastic component end and deal with appearance. Things that are not good are flow lines, thick lines, scratches,etc. We use terminology such as light, very slight, minimum: which is very subjective. I feel we are headed for trouble using these terms. How do you handle appearance items such as these?
Master samples approved by some authority (customer or internal). Keep in mind that these need to be controlled if you use them. Photographs can sometimes also serve the same purpose.
You beat me. I was going to say boundary samples as well. However, beware their drawbacks.
Experiment performed: Boundary samples made and signed off prior to shipping approval. Cosmetic item for Harley. Using boundary samples, 100% visual yeilded 30% plus rejections at Harley. Harley then provides 2 inspectors to 100% inspect outgoing product at the customer's plant after the customer's inspectors and prior to shipping. Rejections at Harley? Stayed at about 30% plus - no reduction...
Moral of story: Cosmetics (visual inspection) are often in the eye of the beholder. But if that's all you have, it's better than nothing.
__________________
A Search is a terrible thing to waste! One Test is Worth 1000 Expert Opinions - The plural of anecdote is not data.
We can't solve problems by using the same kind of thinking we used when we created them. - Unknown
As Deming would say; provide an operational definition.
IMO, first determine when they are not good; when viewed 1" from the surface or 3 feet. Or maybe number of lines , scratches per square inch.
As Deming would say; provide an operational definition.
IMO, first determine when they are not good; when viewed 1" from the surface or 3 feet. Or maybe number of lines , scratches per square inch.
Teknow posted an attachment here that might help give ideas on how to create an "operational definition."
Teknow posted an attachment here that might help give ideas on how to create an "operational definition."
I'll try to get an appearance standard measurement tool scanned in & posted over the next couple of days - if it's printed out on acetate it can be placed over the area of concern to provide a method of measurement.
(alternatively, someone working in automotive may be able to get hold of appearance standard type "ruler" from Ford)
As Deming would say; provide an operational definition.
IMO, first determine when they are not good; when viewed 1" from the surface or 3 feet. Or maybe number of lines , scratches per square inch.
I went through this with Harley. We had little cards as well (see attached) to use for sizing 'dings', pits, etc.
More interesting was there was a Cosmetic 'standard' part of which read something like "Look for no more than 5 seconds at 3 feet".
Obviously there were a lot of conflicts.
My only point here is we must remember - There is theory and there is reality.
__________________
A Search is a terrible thing to waste! One Test is Worth 1000 Expert Opinions - The plural of anecdote is not data.
We can't solve problems by using the same kind of thinking we used when we created them. - Unknown