Process Capability - Interactive Capability Plot

Question

Dear JMP Community,

here my need.

I performed: Data Distribution -> Process Capability. I obtained Process Capability histogram & information (Sigma Capability, Nonconformance,...).

Then I selected: Interactive Capability Plot.

If in the Capability Analysis I selected Normal Distribution: no problem... I can have the Interactive Capability Plot.

But if If in the Capability Analysis I selected other distributions (lognormal, weibull,...): I do not find the Interactive Capability Plot option.

Is it correct or I perform some error?

Thanks in advance for your feedback.

Best Regards,

Simone

SDF1 · Answer

Hi @Simon_Italy ,

I'm not a JMP employee, so I can't say for sure as to what the reason is for the interaction capability plot only working with the normal distribution, but as Byron alluded to in his reply, "...the assumptions of the interaction profiler will work".

So, it appears as if there are some assumptions that go into certain calculations and how the interactive profiler is updated. Likely due to the fact that normal distributions have "nicely" defined parameters like standard deviation and mean. Distributions that are very different from normal tend to have much more complicated mathematical definitions for the parameters that define the distribution function. But, this is just my guess as to why.

Hope this helps,

DS

Simon_Italy · Answer

Dear Byron,

thanks for this "work around" (useful).

I will try to use it for my needs.

Best Regards,

Simone

Simon_Italy · Answer

Dear DS,

thanks for the welcome and feedback (useful).

Do you know the reason that this feature is available only for Normal distribution and not for others?

Is it linked to a statisitcal/techincal constrain... or only a JMP decision?

Thanks

Have you a good day.

Best regards,

Simone