The reasons are not hard to find:

• Six Sigma Black Belt training demands decisions based on fact using the DMAIC (Define, Measure, Analyse, Install, Control) , SIPOC, (Supplier, Input, Process, Output, Customer), VOC (Voice of the Customer) approach and decision making based on fact using such tools as SPC and DOE. rather than untested opinion
• In addition to all the recognised Six Sigma Black Belt tools, The DHI approach embraces the ‘Lean’ concept of operations management. This includes JIT, SMED, Cycle time reduction, TPM, Kaizen (Quality Circles), Hoshin Planning, Policy Deployment (Often referred to as Balanced Score Cards), Customer focussed Design for Six Sigma incorporating Concept Engineering, the Kano Model for determining Customer needs, product Development based on the principles of QFD.
• Supply Chain management development.
• Preparation for later upgrading to Master Black Be