What is a Continuous Improvement Model?

Continuous improvement is one of the most important pillars of Lean. While its definition might sound self-evident, continuous improvement isn’t just an idealistic goal or a catchy slogan to throw on a poster. Continuous improvement is an active, intentional practice, ideally one that is honed across an entire organization. To provide structure to their continuous improvement practice, many organizations choose to follow a continuous improvement model. Continuous improvement models vary in their rigidity of structure, but generally all aim to eliminate waste and improve quality and efficiency of work processes. Read to learn about two different continuous improvement models and determine which one might be right for your organization.

Six Sigma

Perhaps the most widely recognized version of Lean in business, Six Sigma is a continuous improvement model that focuses on eliminating variability and improving predictability in organizations. The goals of Six Sigma are to achieve stable and predictable process results, through clearly defined, measurable processes, and a commitment to sustained quality improvement.

Six Sigma is a disciplined, data-driven approach to continuous improvement. It uses a set of quality management methods rooted in statistical analysis, and relies on an infrastructure of people within the company who are trained experts in these methods to see them through. Six Sigma experts have to work their way through a series of certifications, which are identified by different colored belts, as in karate or judo. Each role comes with specific responsibilities, so success with Six Sigma relies on having each role filled by a qualified expert.

With its statistical tools, certification programs, defined roles and responsibilities, Six Sigma is a highly structured continuous improvement model, ideal for organizations already organized in a structured, corporate way. Learn more about Six Sigma here.


Kaizen is a Japanese word meaning “change for better,” - roughly the English equivalent of the word “improvement.” In Lean, the term Kaizen describes a continuous improvement model that works to improve both flow and process. Compared to Six Sigma, Kaizen is far less structured and rigid. Kaizen is a mindset, a way of working that enables organizations to eliminate waste, improve work quality, and boost morale, empowering all employees to actively participate in the improvement of their daily work.

Unlike Six Sigma, there is no defined hierarchy of roles in this continuous improvement model. Everyone from the CEO to frontline workers, and even stakeholders when applicable, is encouraged to participate in Kaizen.

Kaizen efforts generally target two elements in organizations: flow and process. Flow kaizen efforts are oriented towards the flow of materials and information. Value stream mapping is an example of flow kaizen. Process kaizen is the continuous improvement of individual and team processes. Both involve the use of methodical experimentation - making changes and measuring the results, then adjusting as needed. Experimentation enables organizations using this continuous improvement model to rapidly learn and adapt to changes in the marketplace.

Together, flow kaizen and process kaizen efforts enable a sustainable culture of continuous improvement. Learn more about kaizen here.

Want to Learn More About Continuous Improvement?

These are two of the best known continuous improvement models. To learn more about continuous improvement and other Lean concepts, we recommend the following resources:

Try LeanKit Free!

You're in good company.

Our customers are the best. Read their stories.

Learn More about LeanKit