Six Sigma

What is Six Sigma?


First, what it is not. It is not a secret society, a slogan or a cliché. Six Sigma is a highly disciplined process that helps us focus on developing and delivering near-perfect products and services.

Why ”Sigma“? The word is a statistical term that measures how far a given process deviates from perfection. The central idea behind Six Sigma is that if you can measure how many “defects” you have in a process, you can systematically figure out how to eliminate them and get as close to “zero defects” as possible. Six Sigma has changed the DNA of GE — it is now the way we work — in everything we do and in every product we design.


GE’s Evolution Towards Quality 
GE began moving towards a focus on quality in the late ‘80s. Work-Out®, the start of our journey, opened our culture to ideas from everyone, everywhere, decimated the bureaucracy and made boundaryless behavior a reflexive, natural part of our culture, thereby creating the learning environment that led to Six Sigma. Now, Six Sigma, in turn, is embedding quality thinking — process thinking — across every level and in every operation of our Company around the globe.

Work-Out® in the 1980s defined how we behave. Today, Six Sigma is defining how we work and has set the stage for making our customers feel Six Sigma.

Sigma A term used in statistics to represent standard deviation, an indicator of the degree of variation in a set of measurements or a process.


Six sigma A statistical concept that measures a process in terms of defects—at the six sigma level, there are only 3.4 defects per million opportunities. Six Sigma is also a philosophy of managing that focuses on eliminating defects through practices that emphasize understanding, measuring, and improving processes.



Essentials of the Six Sigma Methodology


The Six Sigma methodology uses statistical tools to identify the vital few factors, the factors that matter most for improving the quality of processes and generating bottom-line results. It consists of four or five phases:


• Define the projects, the goals, and the deliverables to customers (internal and external).
• Measure the current performance of the process.
• Analyze and determine the root cause(s) of the defects.
• Improve the process to eliminate defects.
• Control the performance of the process.

The Six Sigma Strategy

To achieve Six Sigma quality, a process must produce no more than 3.4 defects per million opportunities. 


An “opportunity” is defined as a chance for nonconformance, or not meeting the required specifications. This means we need to be nearly flawless in executing our key processes. Six Sigma is a vision we strive toward and a philosophy that is part of our business culture.


Key Concepts of Six Sigma


At its core, Six Sigma revolves around a few key concepts.


Critical to Quality: Attributes most important to the customer
Defect: Failing to deliver what the customer wants
Process Capability: What your process can deliver
Variation: What the customer sees and feels
Stable Operations: Ensuring consistent, predictable processes to improve what the customer sees and feels
Design for Six Sigma: Designing to meet customer needs and process capability