WHAT IS SIX SIGMA?

Six Sigma is a method that provides organizations tools to improve the capability of their business processes. This increase in performance and decrease in process variation helps lead to defect reduction and improvement in profits, employee morale, and quality of products or services.

The differing definitions below have been proposed for Six Sigma, but they all share some common threads:

The use of teams that are assigned well-defined projects that have a direct impact on the organization's bottom line.

Training in "statistical thinking" at all levels and providing key people with extensive training in advanced statistics and project management. These key people are designated "Black Belts." Review the different Six Sigma belts, levels, and roles.

Emphasis on the DMAIC approach to problem solving: define, measure, analyze, improve, and control.

A management environment that supports these initiatives as a business strategy.

Philosophy: The philosophical perspective of Six Sigma views all work as processes that can be defined, measured, analyzed, improved, and controlled. Processes require inputs (x) and produce outputs (y). If you control the inputs, you will control the outputs. This is generally expressed as y = f(x).

Set of tools: The Six Sigma expert uses qualitative and quantitative techniques or tools to drive process improvement. Such tools include statistical process control (SPC), control charts, failure mode and effects analysis (FMEA), and process mapping. Six Sigma professionals do not totally agree as to exactly which tools constitute the set.

Methodology: This view of Six Sigma recognizes the underlying and rigorous DMAIC approach. DMAIC defines the steps a Six Sigma practitioner is expected to follow, starting with identifying the problem and ending with the implementation of long-lasting solutions. While DMAIC is not the only Six Sigma methodology in use, it is certainly the most widely adopted and recognized.

Metrics: In simple terms, Six Sigma quality performance means 3.4 defects per million opportunities (accounting for a 1.5-sigma shift in the mean).

WHAT IS LEAN SIX SIGMA?

Six Sigma focuses on reducing process variation and enhancing process control, whereas lean drives out waste (non-value added processes and procedures) and promotes work standardization and flow. The distinction between Six Sigma and lean has blurred, with the term "lean Six Sigma" being used more and more often because process improvement requires aspects of both approaches to attain positive results.

Lean Six Sigma is a fact-based, data-driven philosophy of improvement that values defect prevention over defect detection. It drives customer satisfaction and bottom-line results by reducing variation, waste, and cycle time, while promoting the use of work standardization and flow, thereby creating a competitive advantage. It applies anywhere variation and waste exist, and every employee should be involved.

• Lean focuses on waste reduction, whereas Six Sigma emphasizes variation reduction.

• Lean achieves its goals by using less technical tools such as kaizen, workplace organization, and visual controls, whereas Six Sigma tends to use statistical data analysis, design of experiments, and hypothesis testing.

Often successful implementations begin with the lean approach, making the workplace as efficient and effective as possible, reducing waste, and using value stream maps to improve understanding and throughput. If process problems remain, more technical Six Sigma statistical tools may then be applied.

SIX SIGMA CERTIFICATIONS

Six Sigma projects can bring benefits, including increased organizational efficiency, improved customer satisfaction, reduced costs, increased revenues, and more. The Certified Six Sigma Black Belt Handbook reports that many Six Sigma Black Belts "manage four projects per year for a total of $500,000-$5,000,000 in contributions to the company’s bottom line."

Certified Six Sigma Black Belt (CSSBB)

The Certified Six Sigma Black Belt is a professional who can explain Six Sigma philosophies and principles, including supporting systems and tools. A Black Belt should demonstrate team leadership, understand team dynamics and assign team member roles and responsibilities. Black belts have a thorough understanding of all aspects of the DMAIC model in accordance with Six Sigma principles. They have basic knowledge of lean enterprise concepts, are able to identify non-value-added elements and activities and are able to use specific tools.

Certified Six Sigma Green Belt (CSSGB)

The Certified Six Sigma Green Belt operates in support of or under the supervision of a Six Sigma Black Belt, analyzes and solves quality problems and is involved in quality improvement projects. A Green Belt is someone with at least three years of work experience who wants to demonstrate his or her knowledge of Six Sigma tools and processes.

Certified Six Sigma Yellow Belt (CSSYB)

The Certified Six Sigma Yellow Belt is aimed at those new to the world of Six Sigma who have a small role, interest, or need to develop foundational knowledge. Yellow belts can be entry level employees who seek to improve their world or executive champions who require an overview of Six Sigma and DMAIC.