Meet Minitab 14.pdf

Evaluating Process Stability
Assessing Quality
Interpret
X and S chart
Update
control chart
The data points for the Western shipping center fall within the bounds of the control
limits, and do not display any nonrandom patterns. Therefore, the process mean and
process standard deviation appear to be in control (stable). The mean ( ), is 2.985,
and the average standard deviation( S) is 0.629.
Graph updating allows you to update a graph when the data change without
re-creating the graph. Graph updating is available for all graphs in the Graph menu
(except Stem-and-Leaf) and all control charts.
After creating the X and S chart, the Western shipping center manager gives you
more data collected on 3/23/2003. Add the data to the worksheet and update the
control chart.
Add the data to the worksheet
You need to add both date/time data to C1 and numeric data to C2.
1 Click the Data window to make it active.
2 Place your cursor in any cell in C1, then press j to go to the bottom of the
worksheet.
3 To add the date 3/23/2003 to rows 201–210:
■ First, type 3/23/2003 in row 201 in C1.
■ Then, select the cell containing 3/23/2003,
place the cursor over the Autofill handle in
the lower-right corner of the highlighted cell.
When the mouse is over the handle, a cross
symbol (+) appears. Press c and drag the
cursor to row 210 to fill the cells with the
repeated date value. When you hold c
down, a superscript cross appears above the
Autofill cross symbol (+ + ), indicating that
repeated, rather than sequential, values will
be added to the cells.
4 Add the following data to C2, starting in row
201:
3.60 2.40 2.80 3.21 2.40 2.75 2.79 3.40 2.58 2.50
Meet MINITAB 4-5