circuit: Circuit boards data

In qcc: Quality Control Charts

Description

Number of nonconformities observed in 26 successive samples of 100 printed circuit boards. Sample 6 and 20 are outside the control limits. Sample 6 was examined by a new inspector and he did not recognize several type of nonconformities that could have been present. Furthermore, the unusually large number of nonconformities in sample 20 resulted from a temperature control problem in the wave soldering machine, which was subsequently repaired. The last 20 samples are further samples collected on inspection units (each formed by 100 boards).

Usage

data(circuit)

Format

A data frame with 46 observations on the following 3 variables.

x

number of defectives in 100 printed circuit boards (inspection unit)

size

sample size

trial

trial sample indicator (TRUE/FALSE)

References

Montgomery, D.C. (1991) Introduction to Statistical Quality Control, 2nd ed, New York, John Wiley & Sons, pp. 173–175

Examples

data(circuit)
attach(circuit)
summary(circuit)
boxplot(x ~ trial)
plot(x, type="b")
detach(circuit)

Example output

Package 'qcc' version 2.7
Type 'citation("qcc")' for citing this R package in publications.
       x              size       trial        
 Min.   : 5.00   Min.   :100   Mode :logical  
 1st Qu.:16.00   1st Qu.:100   FALSE:20       
 Median :19.00   Median :100   TRUE :26       
 Mean   :19.17   Mean   :100                  
 3rd Qu.:22.00   3rd Qu.:100                  
 Max.   :39.00   Max.   :100                  

qcc documentation built on May 2, 2019, 9:15 a.m.