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Cauchy distribution. Where is Process capability button?

Why where is no Process Capability button? Or you can't do it with Cauchy's distribution data.

 

 

Data Exploration and VisualizationQuality and Process EngineeringRe: Cauchy distribution. Where is Process capability button?

Is this count data?  If so a couple of ideas: You could turn it into pass/fail based upon your defect limit then convert your defect rate to a Ppk from a sigma-DPMO-Ppk table.  You could also fit it as Poisson and use the distribution profiler to determine what your DPMO rate was (by setting the x axis to your spec limit and using the returned Y value) and convert that into a Ppk. The other option would be to turn your zero's into 0.0001's and then you'll have some additional distributions you can fit.

Re: Cauchy distribution. Where is Process capability button?

And, just as an aside, if you're responsible for improving a process that outputs data that are really Cauchy distributed, you might want to update your resume...

Re: Cauchy distribution. Where is Process capability button?

Actually, the mean of the Cauchy distribution is defined but not the higher moments. So, no variance, no standard deviation. No standard deviation, no Ppk.

Re: Cauchy distribution. Where is Process capability button?

but goodness of fit points to Cauchy

 

Re: Cauchy distribution. Where is Process capability button?Check out the other fits.....they might give you good estimatesRe: Cauchy distribution. Where is Process capability button?

yes I click Fit all

And recieve only three, where Cauchy has a priority.

Re: Cauchy distribution. Where is Process capability button?

Have you tried fitting all the Distributions, and then determine which have a significant Goodness Of Fit?  You could then use that distribution for your Cp and Cpk

Re: Cauchy distribution. Where is Process capability button?Yes, but then how do I calculate PPK? Should I take the nearest distribution, if it is? Or should I calculate PPK using Standard Deviation? I need to evaluate the process with nonnormal data distribution.Re: Cauchy distribution. Where is Process capability button?According to the JMP Documentation, the Cauchy distribution has an undefined Mean and Standard Deviation. Based upon that, I assume JMP does not have Cp and Cpk for that distribution and thus no need for the button.Re: Cauchy distribution. Where is Process capability button?Sorry... Why is there no process capability button?