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
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.