7.2. WHAT WE HAVE LEARNED IN CHAPTER 7

  1. Correlation tests are used primarily in the Define, Analyze, and Improve steps of the DMAIC process.

  2. In some Six Sigma classes, regression analysis is used to find correlations. These methods require a high degree of skill and generally are not friendly to those who are not doing this kind of analysis almost daily.

  3. Something changed in a process or product and we would like to discover the key process input variables (KPIVs) that caused it. Time and position are the critical factors in doing the analysis. Using data plots, we first isolate when and where the problem change took place.

  4. Look for a matching time period or position change on data plots of all input variables. Identify all KPIVs that have a change ...

Get Statistics for Six Sigma Made Easy now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.

Start your free trial