Operations · business glossary
What is Six Sigma?
By Shivam Bhandari · Reviewed 31 October 2026 · How we write
definition
A structured methodology for reducing errors and variation in a process to a very small, statistically defined tolerance.
Six Sigma explained
Six Sigma is a data-driven quality method, made famous by Motorola and General Electric, that aims to reduce defects and variation in processes.
example
A packaging plant measures carton defects, finds most come from one machine setting, and fixes it.
why it matters
It brings statistical discipline to quality improvement.
common mistake
Applying heavy Six Sigma tools to simple problems that need only basic fixes.
Frequently asked questions
What is Six Sigma?
A structured methodology for reducing errors and variation in a process to a very small, statistically defined tolerance. Six Sigma is a data-driven quality method, made famous by Motorola and General Electric, that aims to reduce defects and variation in processes.
Why does Six Sigma matter?
It brings statistical discipline to quality improvement.
What is a common mistake with Six Sigma?
Applying heavy Six Sigma tools to simple problems that need only basic fixes.
Related terms
Lean
An operating philosophy focused on systematically removing any step in a process that doesn't add value the customer would pay for.
Quality control
The systematic process of checking that products or services meet a defined standard before they reach the customer.
SOP (standard operating procedure)
A documented, step-by-step process for how a task should be done, so quality stays consistent no matter who performs it.