----- Original Message -----
From: <kmilligan@steelbarsales.com>
To: <www-discuss@lists.insidequality.wegov2.com>
Sent: Thursday, August 09, 2001 12:55 PM
Subject: Defining Accurracy of Micrometers
Is it true that normally the accurracy of a gage,
> i.e. a micrometer, is equal to one division of its reading?
(+/-0.001" on a
> standard OD micrometer)
>
> Thanks
No.
The marks on the gage represent it's level of resolution or
"precision". It's accuracy is defined as what it tells you when it
is used to measure a known and traceable master.
If you check a .2500 length master gage block with your standard
micrometer, and it tells you it measures .251 it's accuracy is
+.001. If it has a vernier scale to measure ten thousandths, it's
resolution is .0001, but it's accuracy is still +.001.
That being said, the purpose is to ensure that we don't use a
yardstick to measure watch parts.
If we know that a gage or inspection tool is accurate to only
.001, we certainly wouldn't want to use it to measure something
that has a tolerance of +/- .001.
In general, we should select measuring tools that have an accuracy
of less than 10% of the tolerance of the characteristics they will
be used to measure.
If we have a characteristic that has a tolerance of +/- .001, we
should have a measuring device that is accurate to +/- .0001.
It's resolution can be either .0001 or .001.
The accuracy is determined during the process of periodic
calibration/verification activities, and must be repeated often
enough to ensure that it's accuracy doesn't exceed acceptable
standards between calibrations.
Hope this helps.
Feel free to contact me off-line if I can be of any further help.
J Bruman
forrestbreyfogle 4/2/2005
INITIAL POSTING: Hello, I have been reading some books on Six Sigma and I am just starting to get into it. In one of the books they say that people often complaint that it is "very" similar to TQM, is this true? I know both systems main goal is "customer satisfaction".
Is this because both systems are based on Dr. Demings theories?
Any feedback will help....one more thing, does anyone know of any training sessions on the subject in N.Y., D.C., VA or MD ?? Thank you
RESPONSE: I will frame my response in generalities since all TQM and Six Sigma deployments are not created equal.
Many TQM and Six Sigma tools are similar. Because of this, many people conclude that the approaches are the "same."
If Six Sigma is deployed correctly, improvement project work within a Six Sigma deployment is more aligned to business needs than TQM was. In addition, Six Sigma had more of an infrastructure relative to project status reporting and roles; e.g., Black Belts, Green Belts, Champions, Executives. Finally, Six Sigma project work had more alignment to business financials; i.e., financial validation of the benefit for each project.
Again, these statements are generalities. I have noted that many companies are having their Six Sigma deployment stalled out because they are "pushing" for project creation, as opposed to creating an enterprise metric system that pulls for the creation of projects in order to improve high-level metrics.
To address your final point, not all Six Sigma training is created equal. You really need to understand what is taught in the course and how you can benefit when choosing a provider. Becoming a good Black Belt who knows how to apply the tools effectively and has a roadmap to accomplish this is much more important than finding a local provider, which can lead to "Black Belt" certification, which may not have much substance.
People can often be penny wise and pound foolish relative to obtaining Six Sigma training. The real expense is a person's time; hence, you need to get the best training you can using "your time."
It has been my observation that those who are trained where the person has to stay in a hotel often do better than those who have local training. Quality Six Sigma training is very intense and involves teamwork after hours, which can more readily be addressed when not being distracted by normal day-to-day late afternoon and evening home-based activities.
Hope this helps.
Contact me directly if you would like to discuss further.
Forrest Breyfogle
Quality Digest's Six Sigma Forum Moderator
forrest@smartersolutions.com
512-918-0280 X401
www.smartersolutions.com
5/31/2006
Six Sigma's originator, Mikel Harry's view is interesting :
"The critical difference between Deming's 14 points (TQM) and Six Sigma is that TQM is espoused and encouraged at the global level of a corporation but most often practiced and reported only at the local level. Six Sigma, on the other hand, is espoused, deployed and implemented at the global and local levels, but it is unambiguously driven and controlled from the top."
I would suggest that there have been many quality managers who have longed for greater commitment by senior management.
Whilst six sigma may be essentially the same as TQM, six sigma has added a layer of nonsense, as discussed in detail in my paper "Sick Sigma".