Cp_X: Calculates the process capability
In XRSCC: Statistical Quality Control Simulation

Description Usage Arguments Details Value Author(s) References See Also Examples

Given a variable sample, the function calculates the process capability and, assuming a normal distribution of the X chart, after the true control limits were found.

1	Cp_X(prev.results, LES, LEI, mu)

`prev.results`	Is a list of previous results obtained by the `xrs_gr` function in the first iteration, or the results obtained in further iterations by the `X_it` function.
`LES`	A numeric vector of length one, containing the upper specification limit.
`LEI`	A numeric vector of length one, containing the lower specification limit.
`mu`	A numeric vector of length one, containing the average specification, if not exists, function takes the Control Limit of previous results.

The function stops for the lack of any arguments.

`Cp`	The process capability index
`Cpk`	The process capability index in case is not centered
`P.cp`	The specification range percentage used by the control limits
`X.sigma`	The process standard deviation
`Conclusion del proceso`	A phrase to take conclusion about the process capability

Erick Marroquin

Montgomery, D.C. (2005) Introduction to Statistical Quality Control, 5th ed. New York: John Wiley & Sons, ISBN 0-471-65631-3

xrs_gr X_it R_it we_rules

data(vol_sample)
results1<-xrs_gr(vol_sample)
results2<-X_it(results1)
# Type dev.off() function before use Cp_X
Cp_X(results2, LES=510, LEI=490, mu=500)

[1] "Proceso fuera de Control en Grafica X"
[1] "El proceso esta bajo control en Grafica R"
[1] "El proceso esta bajo control en Grafica S"
[1] "El proceso esta bajo control en Grafica X"
[1] "El proceso esta bajo control en Grafica R"
[1] "Los limites naturales sobrepasan  los limites de especificacion"
$Cp
[1] 0.7737702

$Cpk
[1] 0.7737702

$P
[1] 129.2373

$X.sigma
[1] 4.307911

attr(,"Concluision del Proceso")
[1] "Los limites naturales sobrepasan  los limites de especificacion"