Need to explore possible correlations?
What product characteristics are correlated to each other?
What do the scatter diagrams look like for each paired set of product characteristics?
How do the product characteristics look when plotted over time on the same chart?
What impact has each of our product had on sales for the year?
Do the changes we make on the two machines have the same impact

Watch a Video Highlighting the Correlation Analysis Techniques in SPC for Excel
Correlation Analysis Techniques and SPC for Excel
SPC for Excel contains six techniques for exploring correlations:
Correlation coefficients
Failure Mode and Effects Analysis
Plotting multiple Y variables against One X variable
Scatter plot matrix
Waterfall charts
BACI charts