Dr. Steve W.
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Dr. Steve W. replied to the topic ANOVA and GLM in the forum General 18 years, 7 months ago

Dr. Steve W. replied to the topic Difference between control and tolerance limit? in the forum General 18 years, 8 months ago
understand, the control limit for xbar is 3 times the SD of group average which is the SD of individual divided by sqrt of sample size. Xbar being in control and within the spec does not imply the individual data are also within the spec. The professor is good.

Dr. Steve W. replied to the topic Am I using the right tool – right approach in the forum General 18 years, 8 months ago
your between run variation is much larger than your within run variation. That indicates that your process is not in control and if it is not in control, it is not meanful to even calculate process capability.
To answer whether you should reduce your sampling frquency, you need to know your rational subgroup. Since your within run variation is…[Read more] 
Dr. Steve W. replied to the topic bye bye six sigma at BOA? in the forum General 18 years, 8 months ago
you and Vince by any chance the same person?

Dr. Steve W. replied to the topic bye bye six sigma at BOA? in the forum General 18 years, 8 months ago
not equivalent to “all of the BB’s and MBB’s heading for the exits” as was stated by Vince. Based on what I have observed, no single MBB has lost job to the merger. It is obvious that Vince is bitter toward BOA and is trying to use this public domain to viciously attack BOA 6S program. I am quite well connected with about 8 major 6S companies an…[Read more]

Dr. Steve W. replied to the topic Statistic in the forum General 18 years, 9 months ago
standard deviation, what do you need CI for?

Dr. Steve W. replied to the topic cp and cpk in the forum General 18 years, 9 months ago
You can have a process with Cp > 2 but all your parts or service are out of spec.! Cp fails to recognize that your process mean has to be in the spec. in order to have a good process. Cp only tells you how good your process can potentially be and it will reach its entitlement only when your process mean is at the middle of the spec. limits. That i…[Read more]

Dr. Steve W. replied to the topic NONPoission Distribution in the forum General 18 years, 9 months ago
long as your subgroup size is 4 or more. The C chart is a little bit more sensensive to deviation from Poission distribution.

Dr. Steve W. replied to the topic NONPoission Distribution in the forum General 18 years, 9 months ago
If so, it is called over dispersion. There are a lot of text books out there that talks about how to handle overdispersion. Overdispersion is very common situation for sount data.

Dr. Steve W. replied to the topic Normal approximation in the forum General 18 years, 9 months ago
you accurately control your type I error (false positive) and it is .3% if you 3 sigma as the control limit. Now if the conditions for normal approximation do not hold, your normal approxmation is not going to be very accurate and hence the type I error can deviate from .3%. Is that going to be a big deal? More often than not, it is not. So do…[Read more]

Dr. Steve W. replied to the topic Bank of America Six Sigma Program in the forum General 18 years, 9 months ago
failed at a U, (s)he tends to have bitter feeling toward that U.. He is trying to launch a personal attack when he does not have facts.
BOA has about 200 MBBs/BBs and majority of them like what they see and the direction the 6S program is moving. Opinions vary and you can never make everyone happy even with a great program.
Anyone is entitled…[Read more] 
Dr. Steve W. replied to the topic Bank of America Six Sigma Program in the forum General 18 years, 9 months ago
The commitment from the senior manage is 2nd to none. Mr. Lewis believes in 6S more than probably any active CEO, he is very knowledgable and probably more knowledgable than you are b/c he was trained by probably the best 6S trainer in this business.
A lot of BBs and MBBs have been promoted to leadership roles. A lot of MBBs and BBs at BOA are f…[Read more] 
Dr. Steve W. replied to the topic Normal approximation in the forum General 18 years, 9 months ago

Dr. Steve W. replied to the topic pvalue Normality in the forum General 18 years, 9 months ago

Dr. Steve W. replied to the topic pvalue from Anderson darling test in the forum General 18 years, 10 months ago
pvalues for 14 (I believe) different distributions. I am not aware any table though. But go to NIST web and you will find some reference on this topic. I would be surprised that some stats handbooks have table for some distributions.

Dr. Steve W. replied to the topic Six Sigma Organization Structure in the forum General 18 years, 10 months ago
what I observed:
1) The consolidated version does not work as well as the deployed version.
2) BBs does not have to report to MBBs but MBBs should have input when it come the PR time for BBs.
3) A structure that has BB reporting to BB can cause issues as BBs are supposed to be measured by similar deliverables. The boss BBs tend to take…[Read more] 
Dr. Steve W. replied to the topic pvalue from Anderson darling test in the forum General 18 years, 10 months ago
dependent in the sense that the same AD value will have different pvalues if the AD value is calculated from different distributions. The pvalue calculation is VERY involved.

Dr. Steve W. replied to the topic Math Help: Intersection of two Normal Distributions in the forum General 18 years, 10 months ago
Sample 100,000 data from the distribution with smaller mean (Calc>random data >..) and store them in Column 1; then do the some thing from the distribution with larger mean and stroe them in a different Column 2. For each of the 100,000 row, count the number of rows for which Column 1 data is bigger than the Column 2 data, and divide that nu…[Read more]

Dr. Steve W. replied to the topic Math Help: Intersection of two Normal Distributions in the forum General 18 years, 10 months ago
I am talking joint density which is represented in 2demensional space and the joint density for 2 independent random variables (RV) are just the product of the 2 individual densities. A 2D joint density is a surface instead just a curve. If you can find someone with MS degree in statistics or industrial engineering, he or she should be able to help.

Dr. Steve W. replied to the topic Boycott Univeristy of Texas at austin BB course in the forum General 18 years, 10 months ago
helps. But it is still challenging for the BB candidates to carry out projects without infrastructure supporting from their companies.
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