In this case, the specification spread is less than the within and overall spread of the process. The process is not meeting requirements.
Part of the Capability Sixpack output, the capability plot helps visibly assess the capability of your process. Use capability plot to
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In this case, the specification spread is less than the within and overall spread of the process. The process is not meeting requirements. |
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In this case, the specification spread is greater than the within and overall spread of the process. The target value is left of the process center. These values are represented by the middle "+" sign on each line. This process spread is contained by the specification spread but not centered at the target. |
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Compare the indices to a reference value to assess whether your process is meeting requirements. A common reference value for Cp, Cpk, Pp, Ppk, and Cpm is 1.33. |
The content of the capability plot depends on your choice of Capability Sixpack analysis: normal, between/within, or nonnormal. The calculations for capability statistics and process spread differ between these methods, but the general interpretation of the capability plot is the same.
