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Hi All, I'm new in this forum (first post actually), even if I read the forum I don't have an answer for this question.
I'm analyzing an appraiser to measure the airtight capability
I measured 20 times the same pumps.
Before starting the test I analyzed the values, not normal distributed.
The Run Chart tells me that there is an oscillation, (p-value 0,048) so I can suppose the process is instable.
The I-mR chart tells me that the process is under control, no problems.
How is it possible? I mean, is it possible a process to be unstable but under statistical control?
Thanks all for your reply
I'm analyzing an appraiser to measure the airtight capability
I measured 20 times the same pumps.
Before starting the test I analyzed the values, not normal distributed.
The Run Chart tells me that there is an oscillation, (p-value 0,048) so I can suppose the process is instable.
The I-mR chart tells me that the process is under control, no problems.
How is it possible? I mean, is it possible a process to be unstable but under statistical control?
Thanks all for your reply

