Answer
It is a methodology and set of tools for the measurement of process quality. It demonstrates that the business process is well controlled. Six Sigma level can be achieved when the accuracy of your process gets only 3.4 defects per million opportunities.

Here’s the list of acceptable number of defects per million to correspond to each Sigma level:

Sigma level               Defects per million opportunities
1                                                690,000
2                                                308,537
3                                                66,807
4                                                6,210
5                                                233
6                                                3.4

Who forms the part of Six Sigma implementation team?

Answer
Attaining Six Sigma is a team effort. An organization who wants to attain Six Sigma needs a lot of restructuring and change in attitude. It includes building up the following roles to take up the required responsibilities:

1. Executive Leadership-Includes CEO and other top management team members. They set up the vision of Six Sigma and empower their team mates with the freedom and resources required for the improvements in the process.
2. Champions- Responsible for the implementation of the process in an integrated manner through out the organization. They come from Top management.
3. Master Black Belts-Act as in-house expert coach for the organization. They assist Champions and train Black Belts and Green Belts.
4. Black Belts-Apply Six Sigma methodology to specific projects. Their focus is on execution of activities for Six Sigma.
5. Green Belts-These are like the soldiers on the war front who actually implement the planned action.