Z Benchmark Potential
               Where
| ZLSL | = | Z benchmark LSL | 
| LSL | = | Lower Specification Limit | 
| = | Sample mean | |
| swithin | = | Sigma within estimate | 
               Where
| ZUSL | = | Z benchmark LSL | 
| USL | = | Upper Specification Limit | 
| = | Sample mean | |
| swithin | = | Sigma within estimate | 
               Where
| ZPotential | = | Z benchmark Potential | 
| ZLSL | = | Z benchmark Lower Specification Limit | 
| ZUSL | = | Z benchmark Upper Specification Limit | 
| Φ-1 | = | Inverse Standard Normal distribution function | 
| Φ | = | Cumulative Standard Normal distribution function | 
               Where
| df1 | = | Numerator degrees of freedom for F distribution | 
| N | = | Total number of observations | 
| Φ | = | Cumulative Standard Normal distribution function | 
| ZLSL | = | Z benchmark Lower Specification Limit | 
| ZUSL | = | Z benchmark Upper Specification Limit | 
               Where
| df2 | = | Denominator degrees of freedom for F distribution | 
| N | = | Total number of observations | 
| Φ | = | Cumulative Standard Normal distribution function | 
| ZLSL | = | Z benchmark Lower Specification Limit | 
| ZUSL | = | Z benchmark Upper Specification Limit | 
               Where
| ZLowerCI | = | Z benchmark Lower CI | 
| Φ-1 | = | Inverse Standard Normal distribution function | 
| = | Value from F(df1,df2) distribution with area of α in right tail | 
               Where
| df1 | = | Numerator degrees of freedom for F distribution | 
| N | = | Total number of observations | 
| Φ | = | Cumulative Standard Normal distribution function | 
| ZLSL | = | Z benchmark Lower Specification Limit | 
| ZUSL | = | Z benchmark Upper Specification Limit | 
               Where
| df2 | = | Denominator degrees of freedom for F distribution | 
| N | = | Total number of observations | 
| Φ | = | Cumulative Standard Normal distribution function | 
| ZLSL | = | Z benchmark Lower Specification Limit | 
| ZUSL | = | Z benchmark Upper Specification Limit | 
               Where
| ZUpperCI | = | Z benchmark Upper CI | 
| Φ-1 | = | Inverse Standard Normal distribution function | 
| = | Value from F(df1,df2) distribution with area of α in right tail | 
Table for Function(n)
| n | Function(n) | 
| Using Ranges: | |
| All n | 
  | 
                  
| Using Sample Standard Deviation: | |
| 2 | 
  | 
                  
| 3 | 
  | 
                  
| 4 | 
  | 
                  
| 5 | 
  | 
                  
| 6-7 | 
  | 
                  
| 8-9 | 
  | 
                  
| 10-17 | 
  | 
                  
| 18-64 | 
  | 
                  
| >64 | 1 | 
10.
Where
| Function(n) | = | Value from table above | 
| n | = | Average sample size | 
| k | = | Number of samples | 

Where
| Cp LowerCI | = | Cp Lower CI | 
| Cp | = | Potential Capability | 
| χ2 (α,df) | = | Value from χ2 (df) distribution with area of α in right tail | 

Where
| Cp UpperCI | = | Cp Upper CI | 
| Cp | = | Potential Capability | 
| χ2 (α,df) | = | Value from χ2 (df) distribution with area of α in right tail | 
                  Where
| Cpk LowerCI | = | Cpk Lower CI | 
| Cpk | = | Demonstrated Excellence | 
| Φ-1 | = | Inverse Standard Normal distribution function | 
| k | = | Number of samples | 
| n | = | Average sample size | 
14.
            Where
| Cpk UpperCI | = | Cpk Upper CI | 
| Cpk | = | Demonstrated Excellence | 
| Φ-1 | = | Inverse Standard Normal distribution function | 
| k | = | Number of samples | 
| n | = | Average sample size | 
                  Where
| PPM<LSL | = | Parts per million less than LSL | 
| Φ | = | Cumulative Standard Normal distribution function | 
| ZLSL | = | Z benchmark Lower Specification Limit | 
                  Where
| PPM>USL | = | Parts per million less greater than USL | 
| Φ | = | Cumulative Standard Normal distribution function | 
| ZUSL | = | Z benchmark Upper Specification Limit | 
                  Where PPMTotal = Total Parts per million
Observed Process Performance:
                  Where
| PPM<LSL | = | Parts per million less than LSL | 
| LSL | = | Lower Specification Limit | 
| N | = | Total number of observations | 
                  Where
| PPM>USL | = | Parts per million greater than USL | 
| USL | = | Upper Specification Limit | 
| N | = | Total number of observations | 
                  Where PPMTotal = Total Parts per million
                  Where
| = | Sample mean | |
| soverall | = | Estimate of overall sigma | 
                  Where
| df | = | Degrees of freedom for χ2 distribution | 
| k | = | Number of samples | 
| n | = | Average sample size | 
                  Where
| Cpm LowerCI | = | Cpm Lower CI | 
| Cpm | = | Potential Capability II | 
| χ2 (α,df) | = | Value from χ2 (df) distribution with area of α in right tail | 
                  Where
| Cpm UpperCI | = | Cpm Upper CI | 
| Cpm | = | Potential Capability II | 
| χ2 (α,df) | = | Value from χ2 (df) distribution with area of α in right tail | 
Computation for Z Benchmark overall:
                  Where
| ZLSL | = | Z benchmark LSL | 
| LSL | = | Lower Specification Limit | 
| = | Sample mean | |
| soverall | = | Sigma overall estimate | 
                  Where
| ZUSL | = | Z benchmark USL | 
| USL | = | Upper Specification Limit | 
| = | Sample mean | |
| soverall | = | Sigma overall estimate | 
                  Where
| ZOverall | = | Z benchmark Overall | 
| ZLSL | = | Z benchmark Lower Specification Limit | 
| ZUSL | = | Z benchmark Upper Specification Limit | 
| Φ-1 | = | Inverse Standard Normal distribution function | 
| Φ | = | Cumulative Standard Normal distribution function | 
                  Where
| df1 | = | Numerator degrees of freedom for F distribution | 
| N | = | Total number of observations | 
| Φ | = | Cumulative Standard Normal distribution function | 
| ZLSL | = | Z benchmark Lower Specification Limit | 
| ZUSL | = | Z benchmark Upper Specification Limit | 
                  Where
| df2 | = | Denominator degrees of freedom for F distribution | 
| N | = | Total number of observations | 
| Φ | = | Cumulative Standard Normal distribution function | 
| ZLSL | = | Z benchmark Lower Specification Limit | 
| ZUSL | = | Z benchmark Upper Specification Limit | 
                  Where
| ZLowerCI | = | Z benchmark Lower CI | 
| Φ-1 | = | Inverse Standard Normal distribution function | 
| = | Value from F(df1,df2) distribution with area of α in right tail | 
                  Where
| df1 | = | Numerator degrees of freedom for F distribution | 
| N | = | Total number of observations | 
| Φ | = | Cumulative Standard Normal distribution function | 
| ZLSL | = | Z benchmark Lower Specification Limit | 
| ZUSL | = | Z benchmark Upper Specification Limit | 
                  Where
| df2 | = | Denominator degrees of freedom for F distribution | 
| N | = | Total number of observations | 
| Φ | = | Cumulative Standard Normal distribution function | 
| ZLSL | = | Z benchmark Lower Specification Limit | 
| ZUSL | = | Z benchmark Upper Specification Limit | 
                  Where
| ZUpperCI | = | Z benchmark Upper CI | 
| Φ-1 | = | Inverse Standard Normal distribution function | 
| = | Value from F(df1,df2) distribution with area of α in right tail | 
                  Where
| df | = | Degrees of freedom for χ2 distribution | 
| k | = | Number of samples | 
| n | = | Average sample size | 
                  Where
| P p LowerCI | = | Pp Lower CI | 
| Pp | = | Performance Index | 
| χ2 (α,df) | = | Value from χ2 (df) distribution with area of α in right tail | 
36.
            Where
| P p UpperCI | = | Pp Upper CI | 
| Pp | = | Performance Index | 
| χ2 (α,df) | = | Value from χ2 (df) distribution with area of α in right tail | 
                  Where
| Ppk LowerCI | = | Ppk Lower CI | 
| Ppk | = | Performance Demonstrated Excellence | 
| Φ-1 | = | Inverse Standard Normal distribution function | 
| k | = | Number of samples | 
| n | = | Average sample size | 
                  Where
| Ppk UpperCI | = | Ppk Upper CI | 
| Ppk | = | Performance Demonstrated Excellence | 
| Φ-1 | = | Inverse Standard Normal distribution function | 
| k | = | Number of samples | 
| n | = | Average sample size | 
Potential Process Performance:
                  Where
| PPM<LSL | = | Parts per million less than LSL | 
| Φ | = | Cumulative Standard Normal distribution function | 
| ZLSL | = | Z benchmark Lower Specification Limit | 

Where
| PPM>LSL | = | Parts per million greater than LSL | 
| Φ | = | Cumulative Standard Normal distribution function | 
| ZUSL | = | Z benchmark Upper Specification Limit | 
                  Where PPMTotal = Total Parts per million
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