Matthew W Ford
QC Formulas and Factors (Updated 02/24/2007 06:43 PM)
a) Variables data, two or more observations per sample
b) Variables data; one observation per sample
Note: r-bar found by finding the average of moving ranges between samples.
c) Attributes data; counted data (c-chart)
d) Attributes data; percentage data (p-chart)
Process Capability Index
Factors For Control Charts and Process Capability
Adapted from ASTM STP 15D ASTM Manual on presentation of data and control chart analysis. Philadelphia: American Society for Testing and Materials.
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