In the company where I worked, there were several levels of Six Sigma:
Green Belt - the worker bees who got a basic short course in Six Sigma theory and practice. As I recall, it was about 1 week of instruction.
Brown Belt - managers were required to become "Brown Belts", which meant that they had to take the same training as Black Belts, but without the requirement that they spend a year herding a project to a profitable conclusion, and without the onus that they would be cast out of their jobs and would have to find new employment within the company at the end of their project.
Black Belt - Four weeks of full time training, plus a project during a four month period which hopefully would show a monetary return (or savings to the company). This is followed by a one year project in which savings must be demonstrated, and at the end of that you lose your job and have to find a new position within the company. At the end of all that you become a "Certified Black Belt".
Master Black Belt - a Certified Black Belt who can lord it over other certified Black Belts. I think it means you can teach the curriculum as well.
I think there are also Six Sigma "sponsors" among the highest levels of executive management, but I'm a bit hazy on the nomenclature and requirements there. Most likely they are also Brown Belts but at the VP level or above.
The basic Six Sigma theory and practice is fine: using a lot of up front analysis and metrics to define and measure the problem before you start throwing solutions at it. Unfortunately in practice (as I found) there is a still a strong tendency in management to pre-ordain conclusions and that leads to a quite horrid Catch-22 trap for aspiring Black Belts. Another problem I encounted was the Six Sigma folks would say, "If the project is obvious, then don't bother with a Six Sigma analysis, just go ahead and do it". My problem was that the main project I was assigned was obvious (pre-ordained), but that there was also a division directive that any project over a certain cost level had to have full Six Sigma justification, and that included my project. "Paralysis by analysis" was an apt term for the result. It was a real Catch-22.
The other problem with Six Sigma is that like any organizational unit, I've heard that in many companies the Six Sigma certified black belts etc tend to become rather arrogant dictators (at least to the non-belts) who would come into a department and make life miserable, with lots of demands for data, metrics, documented processes, etc. Also that the Six Sigmas would form their own sort of clique or secret organization that was less than socially ethical. That was the part of 30 Rock that was most amusing...
The 30 Rock scene where the Six Sigmas are all working on putting together Lego locomotives was not that far from the truth. When I took the training, the big learning activity was designing and building a catapult. One was supposed to use the Six Sigma methodolgy, which basically amounted to taking measurements and arriving at a design and process that would place the projectile on target every time. As I recall it involved wooden sticks, rubber bands, etc. My team mates were mostly managers (Brown Belts) and I was amazed at how mechanically clueless most of them were.
The coolest part of the methodology, for me at least, was the root cause analysis. It was neat to see all the different "symptoms" point back to a common cause. Although it seems logical, it's not an intuitive process because one must continuously think in the reverse of how one is accustomed to looking at problems. That is, we tend to look at a problem and try to find a solution immediately... root cause analysis forces one to forget about the solution for a bit, and instead focus on all the pathways back to the root cause(s). And quite often the actual cause of the problem is something you wouldn't have realized otherwise, or you took for granted.
The other part of Six Sigma that the program likes to point out is that unlike other "quality programs" it requires one to show the economic result of whatever changes the process finds are recommended. Hopefully that result will be a savings or an increased profit. Being a business exercise, that's important. And that tends to appeal to executives and boards of directors. Whether or not Six Sigma allows some fudging of the numbers - or ignoring some costs - to pretend there's a savings when there really isn't any - is another matter. I wonder how many Six Sigma projects showed great savings as Home Depot drove two of its units into the ground?
