Trinkle & Sons performs subcontract body paint work for one of the “Big Three” automakers. One of its recent contracts called for the company to paint 12,500 door panels. Several quality characteristics are very important to the manufacturer, one of which is blemishes in the paint. The manufacturer has required Trinkle & Sons to have control charts to monitor the number of paint blemishes per door panel. The panels are all for the same model car and are the same size. To initially develop the control chart, data for 88 door panels were collected and are provided in the file CarPaint.
a. Determine the appropriate type of process control chart to develop.
b. Develop a 3-sigma control chart.
c. Based on the control chart and the standard signals discussed in this chapter, what conclusions can you reach about whether the paint process is in control? Discuss.