I'm doing a capability study on the flatness of a group of parts. The IDI indicated the Weibull as the best plot use. The LSL on flatness is always 0. What I noticed is if I enter a 0 for the LSL I get a Ppk of 1.08. If I leave the LSL blank I get a Ppk of 2.72. Why this difference and which one should I use.
John Acosta, GDTP Senior Level
Manufacturing Engineering Tech
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