What is Lean Six Sigma and how does it work?

What is Lean Six Sigma and how does it work?

May 26, 2022

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Used for improving business processes by systematically eliminating waste, Lean and Six Sigma are two of the most popular quality management methodologies. When the two work together, they become particularly powerful for business transformation. Lean Six Sigma is the best of both worlds.

What is Lean Six Sigma?” is the question we are all wanting the answer to. In this article, we will go over it, answering some of the most popular doubts regarding this methodology so that you can have a better understanding of the matter.


The whole is greater than the sum of its parts

Lean and Six Sigma are independent methodologies used in different stages of projects. However, the distinction between the two has blurred as more and more companies are using both simultaneously to achieve operational excellence. The concept grew stronger and Lean Six Sigma became a widespread discipline in several industries.

Lean Six Sigma is a combination of the two process improvement methodologies. They can be used individually but work extremely well together, bringing several resources and advantages to the table. But before we dive into Lean Six Sigma, we should look at its ancestors separately.


Lean was developed in the 1950s (post-World War II) by the Toyota Production System (TPS), in Japan. The authors of the concept were Toyota founder, Sakichi Toyoda, his two sons – Kiichiro Toyoda and Eiji Toyoda – and manufacturing engineer Taiichi Ohno. Lean was established in the automotive environment and developed on the principle of streamlining production by eliminating waste.

Lean manufacturing identifies seven wastes (inefficiencies within the activity known as “muda”): Overproduction, Waiting, Transportation, Over-Processing, Excessive Inventory, Motion, and Defects. Focused on removing errors and all the features that consumers don’t look for, Lean became a universal methodology. The core idea of Lean consists of improving relentlessly and providing customer value.

It started in the manufacturing sector, but it has been adapted to many different sectors, from finance to the public sector, health care, and technology. Indeed, Lean was deeply adapted to software development and helped to inspire agile.

Six Sigma

At its core, Six Sigma aims to promote quality throughout an organisation. This methodology was developed in the 1980s by Motorola’s engineer Bill Smith to reduce the variations in its manufacturing processes that were causing product deficiencies.

Six Sigma is fundamentally a toolset for process improvement focused on quality and how efficiency can enable faster outcomes. It seeks “perfection” and defect-free products/services regardless of the industry. The basic premise is this: success happens when everyone within a company, from top to bottom, runs towards a common goal and shares this ethos of working in a defect-free way.

The Greek letter sigma (σ) represents a standard deviation in math and statistics. Therefore, a mature Six Sigma process has no more than 3.4 defects for every million per million opportunities (DPMO – defects per million opportunities), which is to say, defect-free products 99.99966% of the time.

This data-driven methodology aims to refine continuously processes to achieve stable and predictable outcomes. Six Sigma uses a ranking system like martial arts to designate its levels and certificate professionals: White Belt, Yellow Belt, Green Belt, Black Belt, and Master Black Belt.

Maximise your organisation’s potential with Lean Six Sigma

Here is how: Six Sigma focuses on reducing process variation and achieving process control and quality, whereas Lean minimises waste and promotes streamlined processes.

It is important to question and take the time to understand the whys behind the way things work. Adopt a Lean Six Sigma attitude. A mindset of continuous adaptation and development of our work method. This problem-solving culture will help you grow.

Lean Six Sigma provides a combined toolkit that ensures a long-term change in the company’s culture. Lean Six Sigma frees up your resources and makes it possible for you to direct your attention and effort to more fruitful processes. Ultimately, through predictable performance and consistent quality, Lean Six Sigma: decreases costs, improves profit margin, reduces errors rate, simplifies business processes, improves efficiency, and reduces time-to-market.

Lean Six Sigma is implemented in 5 phases. DMAIC is a roadmap for Lean Six Sigma and stands for: #1 Define; #2 Measure; #3 Analyse; #4 Implement; #5 Control.

Do not undermine the importance of managing your resources in an optimised manner. Lean Six Sigma offers a win-win situation where both parties, business, and customer, win. Delivering customer satisfaction is what leads it. This journey of transformation prepares businesses for the constant challenge of customer expectations.

This approach was developed to eliminate waste and minimize every unnecessary aspect/resource of the production process to provide a better response to customers’ needs. It has set a standard for excellence.