ISEL global The Six Sigma approach is typically led by Six Sigma-trained professionals called Black Belts, Green Belts, and Yellow Belts, who are responsible for leading and managing Six Sigma projects within an organization. Lean Six Sigma certification can be applied to any process or industry, from manufacturing to healthcare and service industries. Its goal is to achieve near-perfection in processes, improve efficiency, quality, and customer satisfaction, and achieve significant cost savings