Six Sigma

Six Sigma is a data-driven methodology for reducing process variation and defects, using statistical tools and the DMAIC cycle (Define, Measure, Analyse, Improve, Control). It aims for near-defect-free output and is widely applied in manufacturing quality improvement.

Six Sigma quantifies quality in terms of variation: fewer defects per opportunity means a higher sigma level. Practitioners use structured DMAIC projects, statistical process control and root-cause analysis to find and lock in improvements. It is often combined with lean (Lean Six Sigma) to remove both variation and waste.

Related terms

SPC (Statistical Process Control) · Root Cause Analysis (RCA) · Lean Manufacturing · FMEA (Failure Mode and Effects Analysis)

Where this applies

Running a process capability study · Rolling out statistical process control (SPC) · Improving first-pass yield · Rolling out mistake-proofing (poka-yoke)