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Kicab CastanedaMendez commented on the post, Are You Sure Your Data Is Normal? 3 years, 5 months ago
While the article in general does a good job of describing how one might analyze nonnormal data, there is one issue that needs further addressing. Your Table 2’s last column states “No Assumptions required” for n […]

Kicab CastanedaMendez commented on the post, A Study of Estimates of Sigma in Small Sample Sizes 4 years, 4 months ago
You start your article with “This paper looks at some of the methods of estimating standard deviation (which I will usually refer to as ‘sigma’).” Of course, the method for estimating sigma/standard deviati […]

Kicab CastanedaMendez commented on the post, Use “Light” Lean Six Sigma When the Textbook Approach Is Not Possible 4 years, 8 months ago
I appreciate the intention of the article but would recommend two tweaks to the article.
First, in my nearly two decades of teaching Six Sigma, one thing has been consistent: each company I was employed at or […]

Kicab CastanedaMendez commented on the post, Bringing the Balanced Scorecard Back to Life 4 years, 10 months ago
The articles in isixsigma are deliberately short, so authors are limited in what they can explain and how much detail they can provide. Thus, references are critical for readers to understand in greater depth the […]

Kicab CastanedaMendez commented on the post, Understanding Process Sigma Level 4 years, 11 months ago
This is a good explanation of the calculation of sigma scale values for both short and long term. However, we should be moving past this scale for the following reasons.
1. “In a stable process, the mean n […] 
Kicab CastanedaMendez commented on the post, Avoid Two Common Mistakes in Measurement System Analysis 5 years ago
I like the article. Here are some suggestions to enhance its understandability.
1. You state at the beginning (and provide a formula) “Mathematically, total variance is equivalent to the sum of true variance a […] 
Kicab CastanedaMendez commented on the post, Understand the Difference Between Verification and Validation 5 years ago
You quote Box to state that “all models are wrong,” which I interpret as no model is correct. Thus, using the word “correct” to explain verification and validation is probably not the best choice.
In explaining […] 
Kicab CastanedaMendez posted a new activity comment 6 years, 2 months ago
There are several reasons why your point that “Control chart philosophy more closely follows the Taguchi Loss Function” is not true. The Taguchi loss function is based on the premise that any deviation from nominal or target creates a loss and therefore, rather than having specifications every deviation from nominal should be viewed negatively as…[Read more]

Kicab CastanedaMendez commented on the post, Of Processes and Project Baselines: Why Homogeneity Matters 7 years, 10 months ago
Thanks, Rip.

Kicab CastanedaMendez commented on the post, Of Processes and Project Baselines: Why Homogeneity Matters 7 years, 10 months ago
Hi–I have two more questions about the universe concept.
1. What makes the example in Figure 2 with 5,000 beads a universe?
2. Can you provide a real example of a known universe or tell me whether Deming’s […] 
Kicab CastanedaMendez commented on the post, Of Processes and Project Baselines: Why Homogeneity Matters 7 years, 10 months ago
Thank you, Don.
And what would be the universe for each situation (all or some of the data on the process behavior chart)?

Kicab CastanedaMendez commented on the post, Of Processes and Project Baselines: Why Homogeneity Matters 7 years, 10 months ago
The four questions provide clarity in understanding the role of statistical applications. I understand your description of the first three.
But I am probably misunderstanding the fourth: “Given a collection of […]

Kicab CastanedaMendez commented on the post, A Primer on Nonnormal Data 7 years, 11 months ago
@Darth. Not completely.
First, a parametric test may not be testing the same thing as a nonparametric test (e.g., means vs. medians). So, the means may be different while the medians are not or viceversa. Thus, […] 
Kicab CastanedaMendez commented on the post, A Primer on Nonnormal Data 7 years, 11 months ago
@Darth. Good points about measures of central tendency for normal and nonnormal distributions, robustness of the normality assumptions for some tests, and the normal approximations to various discrete […]

Kicab CastanedaMendez commented on the post, A Primer on Nonnormal Data 7 years, 11 months ago
While the two reasons (although I would have preferred some other word than “pollution”) for nonnormality are accurate, few people realize that the same two reasons occur FOR normality.
Did you know that a […]

Kicab CastanedaMendez commented on the post, Go Beyond Control Chart Limitations to Predict and Improve Processes 7 years, 11 months ago
@Eileen, concerning your statements: “The use of minmax will ignore the statistical distribution of the process and shift the focus to the extremes. Is this really our interest? It feels as though this is a […]

Kicab CastanedaMendez commented on the post, Go Beyond Control Chart Limitations to Predict and Improve Processes 7 years, 11 months ago
Stability can be assessed in a variety of ways, not just with dispersion charts (I may be misunderstanding your third sentences). I, Xbar, and all discrete charts assess stability. They all check whether between […]

Kicab CastanedaMendez commented on the post, Go Beyond Control Chart Limitations to Predict and Improve Processes 7 years, 11 months ago
Mike Clayton,
Without more information, my concern is that these companies with 10k control charts stay in the infancy stage of process improvement. By that I mean, that they rely on patterns of results to […]

Kicab CastanedaMendez commented on the post, Go Beyond Control Chart Limitations to Predict and Improve Processes 7 years, 11 months ago
Mike86, I’m intrigued by your suggestion. I’d like to understand it more. Would you mind explaining it with more detail? Pick one of the problems that is eliminated by the cyclical behavior and tell me how it is […]

Kicab CastanedaMendez commented on the post, Customizing Process Improvement for Financial Services 7 years, 12 months ago
I like Abhishek’s approach to characterizing financial services. However, for three reasons I disagree with his conclusion that “existing traditional process improvement methodologies and tools need to be […]
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