Since no one else has commented, Ill throw in my 2 cents worth but take it with a grain of salt as its not within my area of expertise.
Sub-groups work via the central limit theorem in that they dont affect statistical confidence for most statements formed from groups of those types of measurements, only the measur…[Read more]
It doesn’t sound like you are in a position to implement RTY. You would appear to be inspecting in quality as opposed to using inspection to assure your process is producing quality product.
RTY could help you understand where your rejects are really occurring but you would need to inspect at all the areas you want to understand. If…[Read more]
Good questions, here are some quick thoughts. DOE’s are best applied where continuous variables and non-obvious interactions likely confound a situation. To that end, they never seem to be applied enough in my opinion.
Its an ever present fight to get process experts to truly understand the power of DOE and see where they sh…[Read more]
Im not quite sure where your frustration is. Perhaps you are calculating RTY based on the ten defect types as opposed to the different spots where a part can be rejected? RTY metrics are best applied to determine how many (total) and where in your process your rejections are occurring.
I use RTY all the time on projects where I wo…[Read more]
I maintain a living article on the subject for ASQ San Diego at http://www.asqsandiego.org/articles/cpk.htm. I hope this helps. If you see problems or additions you can make please let me know about them as it is a living article.
KN – http://www.isixsigma.com/library/bio/kniles.asp, http://www.KimNiles.com
Injection molded part strength factors that really stand out are related to creating splay or weld lines. Both of these can be optimized and may appear to come and go depending on what you have in control. Splay is more related to moisture in your mix. Weld lines are more related to cold fronts coming together. Make sure you cov…[Read more]
You are on the right track by purchasing “World Class Quality”. Keki Bohte told me personally during a class I took from him that Dorian Shainin licensed him alone to write about his techniques. This is another reason why you are having problems finding information.
Regarding other comments on this thread, that suggest these tech…[Read more]
One of the prerequisites for MSA is having a stable process. It’s hard to tell from your email but I’d guess you don’t have one. However, I’d also guess that there are other ways to accomplish what you want to accomplish (assure high confidence that you can hire, train, and manage workers so as not to affect production quality r…[Read more]
Thanks Dr. Burns:
I believe we are thinking on parallel paths, just offset a bit from one another due to our vantage points (context).
With regard to your number one, I should have chosen a different word other than set as I meant what you stated. My mistake.
With regard to your number two, again I agree but add that it all dep…[Read more]
Ive really enjoyed reading your posts and wish to thank you for taking the time to make them.
Secondly, I see you worked with Dr. Harry in developing your book Six Sigma Mechanical Design Tolerancing but the book appears to be out of print. How can I get a copy?
KN – http://…[Read more]
Dear Dr. Burns:
Regarding your first scenario (7% of points (depending on the shape of the distribution) to fall outside a control limit) then I argue that you have your control limits set too close together because the process is likely to shift if it contains more than just a few control variables and given enough time. From my exp…[Read more]
We in ASQ San Diego are working on developing a related set of distance education courses that include Six Sigma training in support of the ASQ certification. While we havent actually conducted a course yet, we have developed and posted a list of advantages and disadvantages of what we call e-courses at h…[Read more]
Here are some related bits taken from my CSUDH MSQA thesis entitled “THE IMPORTANCE OF Metrics ON SIX Sigma Program IMPLEMENTATION”.
The 1.5 Sigma Shift Allowance is a way of approximating and accounting for long-term variation of the mean of a process metric. It also conveniently allows Six Sigma targets to appear…[Read more]
Great question Charles:
some form of support for what we do and say
a reward for some form of efforts made
a cheerful reminder of some success in our area of interest
a nice looking picture on the wall (art)
a symbol of hope for our future
a requirement for gainful employment
a form of benchmark for our profession …[Read more]
FYI, I’ve experienced your type of situation many times before and have found that almost all of the time, the best thing to do is to work on the response. It’s rare to have a situation where only discrete output can be used. Theres almost always some form of variable that could be used, either by focusing in more on the output…[Read more]
I would imagine that by now (4 months after your post) you might be finished with your project. If so, how did it go?
My thoughts regarding your question are that if the process is in place and working you should use DMAIC as DMADV is for development mainly. Also, improvement projects tend to follow the Pareto principle such t…[Read more]
Excellent question. I’d like to present a different point of view than what I’ve seen posted.
How many times have we gone into a store and bought something we didn’t know existed or that we didn’t know we needed until we saw it? It happens now and then. Therefore, now and then there is obviously no correlation between VOC and innova…[Read more]
One more point of clarification more specifically related to your question is that covariates in DOE are uncontrolled variables that influence the response but do not interact with any of the other factors being tested at the time. Therefore, if they are present during the experiment then they would show as measurements of e…[Read more]
Your title would appear to be a mistake, as your DOE question does not appear related to TRIZ.
Regarding your question, covariates are random variables you treat as concomitants … or in this case other influential variables that also affect the response. Using DOE, we can deliberately measure the affects of those variables or if w…[Read more]
There are many reasons for choosing a Black Belt candidate and you might or might not fit the pre-planned criteria as well as others around you. Therefore, all you can really do is to communicate your understanding of and interest in becoming a Black Belt.
However, Six Sigma is about improving the bottom line so if you can stat…[Read more]
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