I think you need to provide a bit more background if you want an answer. In particular, what do you want to sort? And why have you already decided that six sigma will be helpful in this case?

@ O. Peter

I agree with Ralf Kneuper - more information needed please. I have not had good experiences with six-sigma. Six sigma always seems to promise a lot but deliver much less. I have had better results with Action Research, which I have written about in the paper below.

Article Enlarging Internal Audit results with Action Research methodology

resolving root cause efficiently