There are mainly two methodologies of Six Sigma namely DMAIC and DMADV.
DMAIC is a data-driven Six Sigma methodology for improving existing products and processes. The DMAIC process should be used when an existing product or process can be improved to meet or exceed the customer’s requirements. DMAIC methodology consists of five phases: D – Define, M – Measure, A – Analyze, I – Improve, C – Control.
DMADV is a common DFSS (Design for Six Sigma) methodology used to develop a process or product which does not exist in the company. DFSS is an application of Six Sigma which focuses on the design or redesigns of the different processes used in product manufacturing or service delivery by taking into account the customer needs and expectations. DMADV is used when the existing product or process does not meet the level of customer specification or Six Sigma level even after optimization with or without using DMAIC. DMAIC methodology consists of five phases: D – Define, M – Measure, A – Analyze, D – Design, V – Validate.