In a previous week you identified a single homogeneous process for which you collected 10 to 30

Control Chart Assignment

1. In a previous week you identified a single homogeneous process for which you collected 10 to 30 consecutive data points. All of the data should have been collected under essentially the same conditions. The differences between the values should be expected to represent nothing more than random variation. (If during the data collection, you observed a significant change in values due to a possible change in conditions, don’t reject the data points; simply make a note of it and include this information in your commentary.)

2. Now you are asked to record these consecutive data points into a single column in a Minitab Worksheet. The Minitab worksheet looks similar to an Excel spreadsheet but does not contain the same cell functions. It is basically just a repository of data. The worksheet should look as follows:

Save your file as a Minitab project using the menu bar at the top: File>Save Project As>file name. The file name will automatically be given the .mpj suffix.

1. The key part of this assignment is to create an Individual Values Control chart of the data as follows: Stat>Control Charts>Variables Charts for Individuals>Individuals. This will open the Individuals Chart window. Double click on your data column in the left pane and this will select your data and place it into the Variables pane. (Click on Help to learn much more about this function.) Click on OK. The results should look similar to the following:

1. Write a short commentary on Individuals Chart results. Pay particular attention to the values of the mean (X-bar), the values of the upper and lower control limits, and where the consecutive data points lie with respect to the control limits. Is the process in control?

Feel free to work together to figure out Minitab, but I think that you will find it to be very user friendly.