Six sigma is a data-driven approach for improving the capability of business processes within an organization. The concept was developed by Bill Smith in the 1989s and was later popularized as a management approach by GE in the early 1990s. Six sigma is principled on quality management fundamentals and it therefore aims to eliminate defects and achieve  well-controlled processes.


Six Sigma yields several benefits in the organization with some of them being:

  • Decrease in variation
  • Reduction in defects
  • Improved employee morale
  • Enhance product quality
  • Increased customer satisfaction
  • Higher profits and cost reduction

Lean vs Six sigma

Although the two approaches overlap they nevertheless carry a few significant differences. Their first major difference lies in their approach to quality management. Lean focuses on waste reduction while on the other hand six sigma focuses on the elimination of defects and variation. Moreover, six sigma is a data-driven approach and uses statistical tools to achieve its goal, while lean employs theoretical-based tools, such as the kaizen philosophy, value stream maps, etc. Many companies use an integrated approach by using lean and six sigma together. This approach is referred Lean Six Sigma and relies on the synergistic use of the two approaches to eliminate waste and reduce variation

Six sigma training and certification

Six sigma professionals are entitled to different color belts that categorize them according to their knowledge and experienced. They are classified as below:

Yellow belt:  Has a basic understanding of six sigma principles and can be assigned to a project as a team member.

Green belt: Works part time or on an ad hoc basis and operates under guidance of black belts.

Black belt: Carries the highest level of training in six sigma methodology and implementation including leading teams and creating projects.

Master Black belt: Mentors groups of black belts and is responsible for their training.

DMAIC Method

Define: The Define phase is the first phase of the six sigma implementation and the main question at this stage is: What problem would you like to solve? The team needs to outline the project focus accordingly.

Measure: The next phase is Measure and it seeks to assess how your project is performing. Is the lead time being improved? Is the variation reduced? Is the quality enhanced? These are all sorts of questions that need to be asked.

Analyze: This is a critical step in the process as it seeks to identify what causes issues to arise. The team needs to think of the root causes of the problem in order come up with valid and concrete solutions.

Improve: Once root causes have been identified, it is important that solutions are thereafter discussed and brought into play.

Control: In this phase you need to sustain the improvement developed in the previous stage. Here, a monitoring plan and a response plan are vital tools for measuring success and updating the six sigma process in the case of something going wrong.

All in all, the fundamental objective of six sigma is the reduction in variation and overall process improvement. By applying the six sigma principles, a company can yield many benefits that are worth the effort.