1. Les Jones IET 603

2. Shewhart Control Charts for: characteristics such as: length, width, temperature and volume. 1.Understand the statistical basis of Shewhart control charts for variables 2. Know how to design variables control charts 3. Know how to set up and use and R control charts 4. Know how to estimate process capability from the control chart information 5. Know how to interpret patterns on and R control charts 6. Know how to set up and use and s or s2 control charts 7. Know how to set up and use control charts for individual measurements 8. Understand the importance of the normality assumption for individuals control charts and know how to check this assumption 9. Understand the rational subgroup concept for variables control charts 10. Determine the average run length for variables control charts

3. Control of the process average or mean quality level is usually done with the control chart for means, or the x control chart. Process variability can be monitored with either a control chart for the standard deviation, called the s control chart, or a control chart for the range, called an R control chart. The X and R (or s) charts are among the most important and useful on-line statistical process monitoring and control techniques. (pg. 227).

4. For x-Charts when we don’t know  Lower control limit (LCL) = x - A 2 R Upper control limit (UCL) = x + A 2 R whereR=average range of the samples A 2 =control chart factor found in Table S6.1 x=mean of the sample means Slide from: Pearson Publishers hilo.hawaii.edu/uhh/faculty/.../361ChapterS.ppt ‎

5. For R-Charts Lower control limit (LCL R ) = D 3 R Upper control limit (UCL R ) = D 4 R where R=average range of the samples D 3 and D 4 =control chart factors from Table S6.1 Slide from Pearson Publishers at: hilo.hawaii.edu/uhh/faculty/.../361ChapterS.ppt

6. (a) These sampling distributions result in the charts below (Sampling mean is shifting upward but range is consistent) R-chart (R-chart does not detect change in mean) UCLLCL Figure S6.5 x-chart (x-chart detects shift in central tendency) UCLLCL Slide from Pearson Publishers at: hilo.hawaii.edu/uhh/faculty/.../361ChapterS.ppt