3.
Production
Process Characterization
3.5. Case Studies 3.5.2. Machine Screw Case Study


Initial Steps  The initial step is to plot box plots of the measured diameter for each of the explanatory variables.  
Box Plot by Machine  The following is a box plot of the diameter by machine.  
Conclusions From Box Plot 
We can make the following conclusions from this box plot.


Box Plot by Day  The following is a box plot of the diameter by day.  
Conclusions From Box Plot  We can draw the following conclusion from this box plot. Neither the location nor the spread seem to differ significantly by day.  
Box Plot by Time of Day  The following is a box plot of the time of day.  
Conclusion From Box Plot  We can draw the following conclusion from this box plot. Neither the location nor the spread seem to differ significantly by time of day.  
Box Plot by Sample Number  The following is a box plot of the sample number.  
Conclusion From Box Plot  We can draw the following conclusion from this box plot. Although there are some minor differences in location and spread between the samples, these differences do not show a noticeable pattern and do not seem significant. 