Craig

Question 1: You would need a set of standards for this. (Items of known values). It would be the same approach as a linearity study, but with additional analysis. Example: I have a set of standards for oxide thickness and they are certified at 1000, 1200, 1400, 1600, 1800, and 2000 angstroms.
Conduct a linearity study, but you could also use a t…[Read more]

Mike,
Same email account.  I think you had 2 defects. (emails that you didn’t respond to) 
You could count all junkmail items that you could have fowarded to me as additional opportunities I suppose.
Planning the May fishing trip already my friend!
HACL

Mike,
You owe me an email or two. How many opportunities do you need?
:-)
HACL  

I thought of doing a google search, but figured it would be better for the professor to explain things like this to the student.
Was the student asking for help or quizzing the six sigma community? :-)

why can’t you get more data and do the analysis correctly?

never heard of data that is co-integrated.  multicollinearity is a condition where the X’s are correlated. Is that what the prof was referring to?
I would get my moneys worth with the professor and have him or her explain this concept.

Go back to the person who made this request. Ask him or her how to put the samples back together again perfectly (kinda like humpty dumpty), and then assess the repeatability of the measurement system with some precision. 
I must confess that I did an experiment in 1989 where the response was a destructive test and I did not do a GRR! However I…[Read more]

This thread seems stranfe

One approach is to capture the data in a binary format for each 30 minute or 1 hr interval during the day. (1 = equip used, 0 = equip not used).
There wouldn’t seem to be a large number of factors driving the use of the equipment. (Operator available?, materials available?, tool in working condition?  Other tool selected?, etc.)
Logistic…[Read more]

Depends what zone the points are in!

Don’t try to force the application of specific tools.
I grabbed one of my text books from the shelf, sneezed from the dust, and opened to chapter 10 (Categorical data analysis). The text is “Statistical Methods and Data Analysis” by Ott and Longnecker. You could look at differences in your response by shift, day of the week, etc.  You would of…[Read more]

1) depends on how many critical outputs you have
2) Depends what the process is. are you baking pies or machining parts, etc?
3) Read up on model fitting
4) Read up on hypothesis testing, anova, etc

Why reinvent the wheel? I would invest in a few software licences.

How about controlling input variables? You have to demonstrate that if the inputs are on target and in control, the Y’s will be adequate. You might be able to reduce your sampling this way.
How large are the rational subgroups and what sort of time period do they represent? This could be the reason you are having issues with the chart signalling…[Read more]

The answer is yes, as long as you have the data to support the change. If it is a highly capable process it is worth pursuing. It is a matter of protecting the customer and keeping your line running in a stable and economical fashion.
Learn the concepts of ARL, alpha risk, OC curves, etc. If you are a good process engineer, you have reduced…[Read more]

I can’t recall ever calculating the p-value by hand. (Used a table with interpolation as Stan mentioned, or obtained directly from software application). Seems like the technique they want you to use should be in the class notes.

There is nothing in this series of posts that will convince me to even care about continual improvment. No offense to anyone intended, but “Continuous Improvement” is all encompassing enough for me. 
What’s the difference between 5S, 5S+, and 6S?  Has anyone gotten into that ridiculous debate?
5S can be a great initiative.
5S+ is still great i…[Read more]

Makes sense to me!  No one seems to care about precision to tolerance ratio any more! I would look at that next.
I have seen the other extreme where the parts chosen are 2X of the tolerance and the study variation is low as a result of that.

122.001 versus 122.003
Are we talking about a difference of .002 microns?

the null hypothesis would be mu = 0
if p is low (less than .05) you reject the null. 
If you reject the null, you should also see that the 95% confidence interval for the mean-difference does not include zero.