Hi G...
As an addition to Eileen's post, Element 8.1 (Measurement, analysis and improvement - General) states:
"This shall include determination of applicable methods, including statistical techniques, and the extent of their use."
I interpret this to mean that we must determine the methods for measuring, analyzing and improving processes and those methods can include statistical techniques, but statistical techniques are not required. However, whatever techniques are used to measure and analyze processes - how we are using them must also be identified.
Does this answer your question?
Cheers!!