Learning to become a competent Black Belt or Green Belt is like learning a trade. When we had our Lean Six Sigma Training programs accredited with the national training body in Australia that certifies all formal tertiary qualifications, I was not surprised that the Black Belt program met the requirements for an Advanced Diploma qualification.Advertised training for Black Belts can vary significantly. From as little as five days to as long as six weeks of face to face training to become a qualified Black Belt.