Whether you adopt the DMAIC or DMADV process of six sigma methodologies, one thing is common in both, you have to define all the aspects of the system. 

 

Therefore, in the six sigma certification process you will be defining first of all the project itself.  This means you have to clearly define what the project is about and what are its ultimate objectives.  Next you will move on to the project management process and thereafter to project charter. 

 

In the process you will have to learn the method of developing the business case.

 

While the defining aspects are mostly common in both the methodologies, the aims and objectives vary vastly.  In the DMAIC methodology you will be defining these aspects with the aim of improving your system.  You will find out and address the defects that have so far been responsible for the debacle your system and organization is facing.

Your objective of defining these aspects under the DMADV methodology is completely different.  Here you will assess and analyze every aspect on the basis of what you customers require or desire to have and how best you could meet their demands. This aspect is vital to success of your business and if addressed adequately, can make good lot of past failures.

That is why in all types of certifications including the lean six sigma or the sigma black belt or any other such processes your starting point is learning defining various aspects of your project.