Six Sigma and Critical Chain are not connected as far as I know, but they were observed in action in the same day. The proposal I'm working on is nearing the Red Team event. For those not familiar with a proposal cycle, Red Team is "red" because of the blood that will be spilled during the 3 days of review. This is a "free and frank" discussion of the success of the proposal team in its efforts to write a several 1,000 page document in 45 days that "wins" a large government procurement.
Six Sigma and Agile
The Six Sigma experience came when I was asked to provide planning guidance to a Kaizen team pulling together a master plan for a flying vehicle, that needs to orbit once and land without mishap to show feasibility of many emerging technologies. I suggested we use the Critical Tools PERT Chart Expert to move all the "stickies" from the wall (about 40 feet by 12 feet of them), into a "Master Plan" that could then be turned in the Critical Path assessment of the program to show that we could actually do what was on the wall. This was the first time I had experience a Six Sigma Team in action. Two Black Belts, several Green Belts, a Planning Lead, a Principle Systems Engineering, gobs of discipline engineers all dancing around waving their hands, arguing over the placement of the stickies, and finally landing on a "to be" system they could sign up to - cost and schedule.
The idea of developing the plan in a single session was not new to me. I've used this technique (without knowing it as Kaizen) many times. What was fascinating was the level of professionalism of the Black Belts and their interaction with the collected team. They simply became the "fluid" between all the ideas. They never rejected an idea, while at the same time sorting out the "poor" ideas from the "winners." When it was done, they had a end to end plan, priorities, accomplishments, criteria and top level task, and rough durations for a major space exploration program.
I got a job posting from a local aerospace firm (not my employer) that listed Critical Chain (TOC) along with IMP/IMS and loads of other "modern" planning processes for a Program Planner position here in Denver. This is becoming more common.