Symbols and Denominations
These are the symbols and denominations used in the software GUI.
Symbols | Description |
|---|---|
CL | Center line |
Cp | Process capability index |
Cpk | Minimum process capability index |
k | Number of subgroups |
LCL | Lower control limit |
LSL | Lower specification limit for the product |
n | Subgroup sample size |
N | Total number of observations |
R | Range of the subgroup observations: difference between the largest and smallest observed value |
Ṙ | Arithmetic average of the R values for the subgroups |
s | Sample standard deviation within the subgroup |
St | Sample (total/overall) standard deviation |
σ | Standard deviation for the population from which samples are taken |
σ̂ | Estimated standard deviation for the population from which samples are taken |
σt | Estimated (total/overall) standard deviation |
UCL | Upper control limit |
USL | Upper specification limit for the product |
X | Measured quality characteristic value, different observed values denoted with X1, X2 .., XN |
̅X̅ | Arithmetic average of subgroup sample observations |
̿X̿ | Total arithmetic average of the sample observations |
