Six Sigma is a data-driven approach and methodology for eliminating defects (any failure to meet a requirement) in any process. It works as well with non-manufacturing processes as with manufacturing processes.  Wherever a “defect” can be clearly defined and measured, Six Sigma methods will make reducing the defect level to meeting requirements a reality.  Six Sigma is aimed at meeting customer requirements, whether the customer is external or internal.

The primary purpose of the Six Sigma methodology is to implement a measurement-based approach that focuses on meeting customer requirements by reducing variation through process improvement projects.

As a business management strategy, Six Sigma was originally developed by Motorola in 1981.  Today it enjoys widespread application in many sectors of industry. While it started in manufacturing and is used in virtually every sector of manufacturing, it is now also used in a very wide range of service industries from finance to hospitality to healthcare. 

The Six Sigma approach seeks to improve the quality of process outputs by identifying and removing the causes of defects (errors) and minimizing variability in manufacturing and business processes.  It uses a well defined set of proven quality management methods, including statistical methods, and creates a special infrastructure of people within the organization who are knowledgeable and experienced in these methods. 

Each Six Sigma project carried out within an organization follows a defined sequence of steps and has quantified targets. These targets are typically financial (cost reduction or profit increase) and whatever is critical to the customer of that process (cycle time, safety, delivery, etc.).   In general, Six Sigma projects are not started until the anticipated financial gains of a successful project have been determined and approved by management.  In many companies Six Sigma is not seen so much as a quality or process improvement tool, but as a way to save money.

Six Sigma is a data-driven approach and methodology for eliminating defects (any failure to meet a requirement) in any process. It works as well with non-manufacturing processes as with manufacturing processes.  Wherever a “defect” can be clearly defined and measured, Six Sigma methods will make reducing the defect level to meeting requirements a reality.  Six Sigma is aimed at meeting customer requirements, whether the customer is external or internal.

The primary purpose of the Six Sigma methodology is to implement a measurement-based approach that focuses on meeting customer requirements by reducing variation through process improvement projects.

As a business management strategy, Six Sigma was originally developed by Motorola in 1981.  Today it enjoys widespread application in many sectors of industry. While it started in manufacturing and is used in virtually every sector of manufacturing, it is now also used in a very wide range of service industries from finance to hospitality to healthcare. 

The Six Sigma approach seeks to improve the quality of process outputs by identifying and removing the causes of defects (errors) and minimizing variability in manufacturing and business processes.  It uses a well defined set of proven quality management methods, including statistical methods, and creates a special infrastructure of people within the organization who are knowledgeable and experienced in these methods. 

Each Six Sigma project carried out within an organization follows a defined sequence of steps and has quantified targets. These targets are typically financial (cost reduction or profit increase) and whatever is critical to the customer of that process (cycle time, safety, delivery, etc.).   In general, Six Sigma projects are not started until the anticipated financial gains of a successful project have been determined and approved by management.  In many companies Six Sigma is not seen so much as a quality or process improvement tool, but as a way to save money.

DMAIC and DMADV

The Six Sigma DMAIC (pronounced Dee-May-Ick) process (Define, Measure, Analyze, Improve, Control) is an improvement system for existing processes which fall below specification and where the organization is looking for significant improvement.

Six Sigma Background

Six Sigma was inspired by six preceding decades of quality improvement methodologies such as quality control, TQM, and Zero Defects, based on the work of Quality pioneers such as: Walter Shewhart,  W. Edwards Deming,  Joseph Juran, Kaoru Ishikawa, Genichi Taguchi and others.

Like its predecessors, Six Sigma methodology asserts that:

• Continuous efforts to achieve stable and predictable process results (i.e., reduce process variation) are of vital importance to business success.
• Manufacturing and business processes have characteristics that can be measured, analyzed, improved and controlled.
• Achieving sustained quality improvement requires commitment from the entire organization, particularly from top-level management.

Features that set Six Sigma apart from previous quality improvement initiatives include:

• A clear focus on achieving measurable and quantifiable financial returns from any Six Sigma project.
• An increased emphasis on strong and passionate management leadership and support.
• A special infrastructure of "Champions," "Master Black Belts," "Black Belts,"  “Green Belts” to lead and implement the Six Sigma approach.
• A clear commitment to making decisions on the basis of verifiable data, rather than assumptions and guesswork.

Black Belts, Green Belts and Yellow Belts, Oh My

The notion of “Belts” in Six Sigma loosely follows the concept in the martial arts, where moving through a series of different colored belts signifies increased competence.

Six Sigma Black Belts are practitioners who have completed a somewhat standardized curriculum that will take around 160 hours to complete. Virtually all providers of Six Sigma training require the successful completion of a project for the student to receive their Black Belt certificate.  Typically a Black Belt provides direction, and works with a number of Green Belts on a project until completion. Black Belts may complete two to four projects a year, with cost savings around $200,000 per project being typical, while projects saving more than $1,000,000 are not unheard of.

Master Black Belts have successfully completed a number of projects and have a proven track record of providing guidance to Black Belts.  There does not appear to be any industry wide standard of what a Master Black Belt is.

In most organizations Black Belts are supported by a combination of Green Belts and/or Yellow Belts.  There is no real standardization regarding what a Green Belt is. Depending on the training provider, Green Belt Curriculum seems to range from 24 hours to 80 hours.

The American Society for Quality (ASQ) provides on a semi-annual basis, an examination for what ASQ referrers to as an ASQ Certified Green Belt. This has become the closest thing to an industry standard for what a Green Belt is.  Training providers working towards the ASQ Certified Green Belt Body of Knowledge all seem to be providing an 80 hour curriculum.

A number of organizations have discovered that 80-hour trained Green Belts are capable of completing many Six Sigma projects.  The conventional wisdom has been that only Black Belts can run a Six Sigma project. However, the reality is there are many projects that have resulted in significant cost savings that were completed by experienced Green Belts with very minimal help from a Black Belt.  Unless an organization has a history of ongoing process improvement efforts, there are likely many projects worth doing that could be addressed by experienced Green Belts.

Larger, corporate type organizations may have additional, lower level practitioners referred to as a Yellow Belts. Typically Yellow Belts have one to three days training and support Green Belts and Black Belts.

Six Sigma Champions

If you ask most people involved in Six Sigma what a Champion does, they would reply, "they remove roadblocks." Superficially, that is true. Champions need to be in a position to defuse any issues that may arise between a Black Belt and another person in the organization, particularly if the issue is with someone with a higher formal position in the company. The Champion should be the buffer that keeps a Black Belt out of a head-to-head confrontation with Managers, Vice Presidents and Directors in the company, allowing Black Belts the freedom to focus on the problem, not be distracted by territorial disputes. This is the most fundamental function of the Champion.

Six Sigma Champions must also be proficient in four other areas.

·         First, business and operations interface: assure that operational level projects are aligned with the strategic level business objectives.   

·         Second, project selection: after ensuring projects that are in alignment with organizational goals are selected, then making sure the right Six Sigma practitioner is selected to run the project. 

·         Third, project schedule mediation: ensuring the project deployment does not become protracted. 

·         Fourth, results implementation: ensuring that the financial benefits which justfied the project, do in fact materialize.

Lean Six Sigma

In recent years, some practitioners have combined Six Sigma ideas with lean manufacturing to yield a methodology named Lean Six Sigma.  Lean Six Sigma aims to increase process velocity, reduce waste and reduce variation. Many organizations that started with Lean or Six Sigma, found adding the other practice moved their improvement efforts are a much faster rate.

Six Sigma is a registered service mark and trademark of Motorola Inc.