Six Sigma

A Variation Story

By Ron Pereira Updated on January 13th, 2011

Measurement Systems AnalysisIf you test or inspect (visual or automatic) a product of any kind I’m very confident I can show you how to save your company thousands, if not millions, of dollars (or Euros, Pounds, etc.).

How you ask? Three words. Measurement Systems Analysis, or MSA for short. But first a true story.

Back in the Day

In a past life I was working with a supplier that provided my former company with some critical plastic components for the product we produced. I’m purposely being vague to protect the innocent!

Anyhow, we were having some problems with the aforementioned critical components so I went to the supplier to see if I could help.

After some investigation and discussion we decided to run a design of experiment (DOE) on the injection molding process that produced these parts.

A Simple Question

Being the good six sigma guy I try to be, the first thing I asked the engineer I was working with was if they had ever done a measurement systems analysis of the optical inspection machine used to measure the actual dimensions of the parts.

He went on to explain how this very expensive inspection machine had just recently been calibrated to the “gold standard.” I wasn’t quite sure what the gold standard was… nor did I care how calibrated it was.

I asked him again, “Have you ever done an MSA.” He was growing frustrated with me and finally admitted… no, they had never done an MSA.

Let’s do it!

Happy to finally hear this I asked him to collect 15 of the parts we were planning to measure.

About 8 minutes later he had the 15 parts.

We grabbed a couple of operators and proceeded to conduct a variable data measurement systems analysis. It took us about 30 minutes to complete the entire study.

I threw the data into some statistical software and did the analysis.

Houston, we have a problem

Guess what? We failed the test. And I don’t mean fail like we did sort of bad. I mean fail like this fancy optical inspection machine that had recently been calibrated to the gold standard couldn’t tell the difference between a good part and bad part if its life depended on it. Good thing it wasn’t alive!

In other words, this supplier had no earthly clue what the *true* dimensions of these components were.  Not good.

The Rest of the Story

Tomorrow night I’ll explain exactly how we solved the problem in less than 60 minutes. By the way, the cost of poor quality of this particular problem was resulting in millions of dollars of damage each year.


  1. mohamed

    October 28, 2008 - 9:04 am
    Reply

    would you mind to send me any material around this topic, we have a tool like this but called gauge R& R as it would be a good tool in the process certification.

    i’d like to get any advise or help to understand this topic.

    I’m interseting and care it.

    Thanks, Mohamed

  2. Ron Pereira

    October 28, 2008 - 9:27 am
    Reply

    Stay tuned, Mohamed. There is plenty more to come.

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