Cp_X {XRSCC}

Calculates the process capability

Description

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.

Usage

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

Arguments

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.

Details

The function stops for the lack of any arguments.

Value

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

Author(s)

Erick Marroquin

References

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

See Also

xrs_gr X_it R_it we_rules

Examples

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)