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#### ejmoska

Hello,

just a small question to which i can't seem to find an answer:

For Cpk calculation, we have:

Target 0%

UCL 2%

LCL -2%

USL 4%

LSL -4%

when calculating Cpk, should we be using LSL/USL or LCL/UCL?

also, if we have out of spec values somewhere within results, should they be left there to display "true" Cpk or moved to another metric, like FPY?

What if the out-of-spec data, jumps to i.e -99%, -30% or 20% this greatly affects mean value, and Cpk no longer shows accurate data. So far we are removing such values which greatly affect mean, but is this really the correct way to go?

just a small question to which i can't seem to find an answer:

For Cpk calculation, we have:

Target 0%

UCL 2%

LCL -2%

USL 4%

LSL -4%

when calculating Cpk, should we be using LSL/USL or LCL/UCL?

also, if we have out of spec values somewhere within results, should they be left there to display "true" Cpk or moved to another metric, like FPY?

What if the out-of-spec data, jumps to i.e -99%, -30% or 20% this greatly affects mean value, and Cpk no longer shows accurate data. So far we are removing such values which greatly affect mean, but is this really the correct way to go?

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