The Run Chart plots individual observations in run order. It can also perform tests for trends, oscillation, mixtures and clustering (special causes or non-random behaviors).
1. Choose ProcessMA > Graphs > Run Chart.
2. In Variable, select the column containing the data.
3. Click OK.
Optional
4. Check Non-parametric run test, if you want to perform tests for trends, oscillation, mixtures and clustering.
5. Check Show median if you want to plot the median of the data as a reference line.
6. Check Show mean if you want to plot the mean of the data as a reference line.
Note To select a column of data into a textbox, double-click on any of the column names shown in the list on the left of the dialog box while in the textbox.
Variable: Numeric.
You are the quality control engineer in an electronic manufacturing plant. You need to ensure that the switches manufactured are durable. You collected data from the testing laboratory on the number of times the switches are used before breaking down. You want to generate a Run Chart to study the variation.
1. Open worksheet ProcessMA > Tools > Data Files > Sample.xls.
2. Choose ProcessMA > Graphs > Run Chart.
3. In Variable, select C – Switches.
4. Check Non-parametric run test.
5. Check Show median.
6. Click OK.
Interpretation
The P-value for clustering is 0.033. If the desired level of significance is 0.05, it suggests that there are special causes in the process.