XbarR.CapabilityIndexCpk Method

XbarRCapabilityIndexCpk Method

Returns the capability index $c_{pk}$ .

Namespace: Imsl.Chart2D.QC
Assembly: ImslCS (in ImslCS.dll) Version: 6.5.2.0

Syntax

public virtual double CapabilityIndexCpk(
	double lowerSpecificationLimit,
	double upperSpecificationLimit
)

Public Overridable Function CapabilityIndexCpk ( 
	lowerSpecificationLimit As Double,
	upperSpecificationLimit As Double
) As Double

public:
virtual double CapabilityIndexCpk(
	double lowerSpecificationLimit, 
	double upperSpecificationLimit
)

abstract CapabilityIndexCpk : 
        lowerSpecificationLimit : float * 
        upperSpecificationLimit : float -> float 
override CapabilityIndexCpk : 
        lowerSpecificationLimit : float * 
        upperSpecificationLimit : float -> float

Parameters

lowerSpecificationLimit: Type: SystemDouble
The lower specification limit.
upperSpecificationLimit: Type: SystemDouble
The upper specification limit.

Return Value

Type: Double
The capability index $c_{pk}$ .

Remarks

The capability index is

$c_{pk}=\min\left[\frac{\mathrm{USL}-\bar{x}}{3\sigma},\frac{\bar{x}-\mathrm{LSL}}{3\sigma}\right]$

where LSL and USL are the lower and upper specification limits, $\bar{x}$ is the center line, and

$\sigma=\frac{\bar{R}}{d_{2,n}\sqrt{n}}$

Reference

XbarR Class

Imsl.Chart2D.QC Namespace