mavii

The following statements create the chart shown in Output 38.4.1 ... and it is decided to eliminate these batches from the data set and recompute the control limits. The following statements create a data set named FAILLIM2 that contains the revised ...

The upper control limit is calculated from the data that is plotted on the control chart. It is placed 3 sigma (of the data being plotted) away from the average line.

The control limits represent the upper and lower expectations of the process variation. The control chart was developed by Dr. Walter A. Shewhart while working at Bell Labs in the 1920s.

Finally, the following statements create a box chart for LOGLENG that displays control limits for the subgroup maximum: title 'Box Chart With Control Limits for the Subgroup Maximum'; symbol v=none; proc shewhart data=lengdata limits=maxlim; boxchart ...

3. Use and interpret control charts (p442). 1. Obtain 20-25 samples. Compute the appropriate sample statistic(s) for each sample (e.g. mean). 2. Establish preliminary control limits using the formulas 3. Determine if any points fall outside the control limits.