An important twist in this question -
We have come across senior professionals making statements of the following types.
Although I have not undergone Green Belt training (or for that matter, any formal Six Sigma training), I should be allowed to directly attend Black Belt training.
Seniority should be made criteria for direct entry into Black Belt.
I have been in the industry for more than 10 years.
If someone needs a Black Belt without undergoing Green Belt, he/she should consider ten days black belt training (PLUS 2-4 days of pre-course and mid course self-study and practice exercises).
This ten days Black Belt training can be obtained by enrolling into our 4 days Green Belt followed by 6 days Black Belt (both having pre-course and mid course self-study and exercises).
What I mean is quite obvious - there are no short cuts. It is important to complete graduation before considering post graduation.