Six Sigma emphasizes the following four points:
- Know what is important to the customer. Whatever improvement project you are doing, make sure that it is important to your external customers. Any improvement project should be aligned with the customer's needs, expectations, or satisfaction. (critical to quality)
- Reduce defects. Six Sigma emphasizes reducing defects to the level of 3.4 defects per million opportunities (DPMO).
- Target at the mean. Six Sigma looks to achieve the center of tolerance, rather than being within tolerance. For example, if you are making a piece with the dimension of 100 mm, then you should be targeting at 100 mm, rather than between 99 mm and 101 mm.
- Reducing variation. Six Sigma believes in reducing variation. Even though variation is everywhere, it is the enemy of quality. Quality is related to consistency.