The question is Suppose you work at a car assembly plant in a department that assembles engines. In an operating engine, parts of the crankshaft move up and down a certain distance from an ideal baseline position. (A to B Distance) is the distance (in mm) from the actual (A) position of a point on the crankshaft to the baseline (B) position.

To ensure production quality, you took five measurements each working day, from September 28 through October 15, and then ten per day from the 18th through the 25th. Create an Xbar and R Chart of the data (What does it show) does it fail any test? Now let's say you want to look for small shifts away from the target, you want to plot the CUSUMs.

Follow these directions to create the charts Xbar - R

1.Open the worksheet CRANKSH.MTW.

2 Choose Stat > Control Charts > Variables Charts for Subgroups > Xbar.

3 Choose all observations for a chart are in one column, then enter AtoBDist.

4 In Subgroup sizes, enter Day.

5 Click Xbar Options, then click the Tests tab.

6 Choose Perform all tests for special causes.

7 Click the S Limits tab.

8 Under Display control limits at, enter 1 2 3 in these multiples of the standard deviation. Click OK in each dialog box. CUSUM CHART

1 Open the worksheet CRANKSH.MTW.

2 Choose Stat > Control Charts > Time-weighted Charts > CUSUM.

3 Choose All observations for a chart are in one column, then enter AtoBDist.

4 In Subgroup sizes, enter

5. Click OK. Answer the following questions

1. Did the Xbar-R chart fail any test? __________ If so how many__________ What test(s) did it fail? __________________________________________________________________________________

2. Where there any points outside the control lines of the CUSUM chart? ___________

3. At what point if any was outside of the CUSUM chart?

4. What would a point outside the CUSUM chart indicate, what action should be taken?