Coefficient of Variation ...

COV is a very powerful tool to take a process and to search for the greatest sources of variation within it. To get the maximum effectiveness you have to have an idea of what you’re looking for. Is variability a factor of time, location, or as things come off serially. I typically recommend that BBs perform this analysis prior to launching into a DOE. It’s also a good check to see if there is understanding of the process and that ‘define’, ‘measure’, and ‘analyze’ are progressing . The information that you gain from this analysis can make the subsequent DOE much more powerful and hone in on the true critical Xs.

Regards,

Erik