Hello JMP Community,
How can I calculate Pooled Variance in JMP?
I am hoping, as with all things JMP, this exists and I have just not found the magic pathways to produce the desired results quickly and efficiently. I can of course do this by going through the actual maths myself, but I have frequently run into this situation so it would be great to learn if this already exists in JMP.
I have a data set that is grouped by process conditions which have differing means as a result of process centering (tuning) activities. I would like to generate a pooled variance estimate for this process for use in specifications/capability estimates in support of this new process launch. My total run count is rather low so for initial process variability/capability discussions I would like to do this to increase my N count.
Technical Situation
- Process 1 Condition A, was running at lower end of our desired process window [n=8]
- Process 1 Condition B, changed our tuning lever to center the process (new) to the desired target [n=10]
- The process change resulted in a mean shift, but did not change the process variability (and fundamentally was not expected to)
- I would like to generate the "Pooled Variance" estimate for the P1CA + P1CB
- As this is a new process, my data set is limited, so the desire is to use this to enable a increase n count during initial capability discussions
This is the simply case. I have much more complex cases but they all follow this same scenario where variance is unaffected when a lever was pulled to create a mean shift.
Thank You,
WanderedProcess
***sorry if a thread exists detailing this. I did try searching key terms I am familiar with. =-] ***
