Back in the days (early 2000s) I tried to "sell" to a well-known aerospace company this "three-legged stool" approach of stable continuous organizational #changemanagement, where #sixsigma stands just as one of the many different tools one can choose from in dealing with the different #products of the organization, along with tools and methods more appropriate to deal with the other two aspects of the organization #people and #process.
As one could have expected, those "black belts" on the other side of the table didn't like it 😀.
They went with a strategy where a version of six sigma was used as the "foundation" for all process improvement efforts and everything else was subordinated to it.