kstats-core/org.oremif.kstats.descriptive/ProcessCapabilityResult

ProcessCapabilityResult

data class ProcessCapabilityResult(val cp: Double, val cpk: Double, val pp: Double, val ppk: Double)(source)

Results of a process capability analysis.

Contains four standard SPC (Statistical Process Control) indices that measure how well a process fits within its specification limits. Values above 1.0 indicate a capable process; values above 1.33 are generally considered good.

Cp and Cpk use the sample standard deviation (divides by n-1) as the spread estimate, while Pp and Ppk use the population standard deviation (divides by n).

Constructors

ProcessCapabilityResult

constructor(cp: Double, cpk: Double, pp: Double, ppk: Double)

Properties

val cp: Double

potential capability — compares the tolerance width to 6 times the sample standard deviation. Ignores process centering.

cpk

val cpk: Double

actual capability — like cp but penalizes the process for being off-center relative to the specification limits. Always less than or equal to cp.

val pp: Double

potential performance — same formula as cp but uses the population standard deviation instead of the sample standard deviation.

ppk

val ppk: Double

actual performance — same formula as cpk but uses the population standard deviation. Always less than or equal to pp.

ProcessCapabilityResult

See also

Constructors

Properties