What is Six Sigma?

What are the main principles of Six Sigma?

1. Everything starts and ends with the customer.
2. A different view: “every task is a process”.
3. Process oriented: “limit the island culture”.
4. Eliminate defects: “variation is the enemy”.
5. Decisions based on facts and data: “show me the data”.
6. Financial results as the starting point.

What is DMAIC and what do the five phases mean?

Six Sigma works in five phases, the DMAIC method.

In the Lean Six Sigma Green Belt training you learn to apply Six Sigma and DMAIC to an improvement project in your own organisation.

D = Define. In this first phase you describe the problem you are working on and its value for the business. The customer’s wishes are made visible.

M = Measure. You measure the process, collect basic information about the process or product and set the improvement goals.

A = Analyse. You determine the main causes: the process factors with the most influence on the outcome of the process.

I = Improve. You determine the best ways to improve process performance and test these solutions.

C = Control. The best solution is implemented, and the project and the new way of working are secured and handed over.

Why use Six Sigma and what does it deliver?

Six Sigma makes processes predictable. With data you find out where defects and variation come from, and you tackle the cause instead of the symptom. That delivers:

• fewer defects, rejects and rework;
• lower costs, because there is less duplicate work and waste;
• satisfied customers, because they get what was agreed, every time;
• decisions based on facts instead of gut feeling;
• improvements that last, because you secure them in the Control phase of DMAIC.

Where does the name come from?

Sigma (σ) is the Greek letter that stands for the standard deviation in statistics: a measure of the spread around the mean. The more standard deviations fit between the mean of your process and the limit of what the customer accepts, the fewer defects. A process at six sigma produces 3.4 defects per million opportunities (with the usual shift of 1.5 sigma).

Six Sigma was developed at Motorola in 1986 by engineer Bill Smith. From 1995 General Electric, under Jack Welch, made it the core of its business strategy, and from there it spread to other companies. Today Six Sigma is used not only in manufacturing, but also in business services, logistics, government and healthcare.

Which roles are there in Lean Six Sigma?

An important innovation of Six Sigma is the professionalisation of quality management. Before, quality was mostly left to the shop floor and to statisticians in a separate quality department. Six Sigma names its levels after the belts in martial arts such as judo. This creates a clear structure, and a career path, that runs through all functions and levels. The method distinguishes several key roles for a successful implementation.

• Master Black Belts, appointed by Champions, are the internal coaches for Six Sigma. They spend all their time on Six Sigma, help Champions and guide Black Belts and Green Belts. Besides statistical work, they make sure the method is applied the same way in every department.
• Black Belts apply the Six Sigma method to specific projects, under the guidance of Master Black Belts. They work on it full time and focus mainly on running and leading projects. Champions and Master Black Belts decide which projects and processes come next.
• Green Belts run improvement projects alongside their regular work, guided by Black Belts. Good training makes sure they follow the method and use the data-driven approach correctly.

Some organisations use more belt colours, such as Orange Belts for employees with basic training who take part in projects, and White Belts for those who know the concepts but are not in a project team.

What is the difference between Lean and Six Sigma?

In short: Lean focuses on eliminating waste and creating flow in a process. Six Sigma focuses on reducing spread within a process.