# Overview of Six Sigma

## What is Six Sigma

σ

In Statistics, the Greek Letter **sigma** (**σ**)

Refers to “Standard Deviation,” a Measure of Variation.

### In Business, Variation (σ) Exists in All Processes

Variation Occurs Naturally and/or by Special Cause. It Doesn't Matter if You're Creating Widgets in Production, or Serving Patients in Healthcare.

### A Six Sigma Process

A Six Sigma Process Has **Six (6) σ** Between its Mean and the Nearest Specification Limit. There is Ample Room for Natural Variation. This Process Only Yields ** 3.4 Defects per Million Opportunities**.

Specification Limits Can Be Set by Customers or Businesses

**LSL** = Lower Specification Limit | **USL** = Upper Specification Limit

### A One Sigma Process

A One Sigma Process Has Only One (1) σ Between its Mean and the Nearest Specification Limit. There is No Room for Natural Variation. This Process Yields Nearly 70% Defects.

Specification Limits Can Be Set by Customers or Businesses

**LSL** = Lower Specification Limit | **USL** = Upper Specification Limit

Sigma (σ) is the Measure

Six (6) is the Goal

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## D.M.A.I.C is the Method..

**Sigma** is the Measure | **Six Sigma** is the Goal | **D.M.A.I.C.** is the Method Used to Achieve the Goal

D.M.A.I.C. is a Project Management Methodology.

D.M.A.I.C. is Used When We Don't Know the Answer.

Otherwise, Use a Traditional Project Management Method (Waterfall, Agile)

## Six Sigma Methodology

Six Sigma follows a methodology that is conceptually rooted in the principles of a five-phase project. Each phase has a specific purpose and specific tools and techniques that aid in achieving the phase objectives.

#### D.M.A.I.C. is a Process Taught from Define Through Control

However

**D.M.A.I.C. is NOT Strictly Linear**

Y=f(x) is a **transfer function.
**It is a Mathematical Expression of the Relationship Between the Inputs and Outputs of a System.

**Y = f(x)** is the Relational Transfer Function That is Used by All Six Sigma Practitioners.

It is critical that you understand and embrace this concept.

As a Six Sigma Practitioner, Your Job is to Use The DMAIC Methodology,

Weed Through All the Noise, and Identify the Critical X's

## Lean Six Sigma History

DESIGNATIONS

SS = Six Sigma

LSS = Lean Six Sigma

YB = Yellow Belt

GB = Green Belt

BB = Black Belt

MBB = Master Black Belt

NOTES

MBBs and BBs Facilitate Training and Mentor Others.

Master Black Belts Advise Champions and Sponsors.

Champions and Sponsors Should be Yellow Belt Trained.

#### Master Black Belt (MBB)

Master Black Belts have the highest level of certification, leadership experience, and project experience.