Lean Six Sigma

The basics

Lean Six Sigma is a coming together of both Lean Management and Six Sigma. Lean Management is best defined as “a management philosophy focused on identifying and eliminating waste throughout an entire value stream, extending not only within the organization, but also along its entire supply chain network”. Six Sigma is best defined as “an organized and systematic methodology for strategic process improvement and new product and service development that relies on statistical methods and the scientific method to make dramatic reductions in customer defined defect rates”. Together Lean Six Sigma can best be defined as “a structured data-based approach for sustainable process improvement”.


Lean Six Sigma is the global standard for organizing the design, data-based improvement and control of both manual and digital business processes. Well-designed and controlled processes are key in achieving and sustaining operational excellence. They ensure the quality of service and care, the reliability and safety of work that is done, and a timely processing with short waiting times. High quality processes will at the same time improve the operation’s flexibility. Thereby allowing one to adjust to changes in demand and other circumstances. An organizational capability to harness data-based process improvement, finally, facilitates organizational learning and is foundational for the fruitful implementation of ever-increasing digitization and automation opportunities.

Lean Six Sigma offers a complete model for shaping modern continuous improvement programs in organizations. The methodology is built on principles and methods for fact-based process improvement that have proven themselves over the last decades, and will continue to do so in the decades to come. Having emerged in manufacturing, the approach continuously evolved and gained tremendous momentum in other industries (e.g. services, healthcare, public administration, education, etc.).

Core principles of the Lean Six Sigma methodology:

1.  Professional and science-based problem solving.

2.  Precise, quantitative and business case-based problem definition.

3.  Data-based diagnosis.

4.  Innovative generation of new ideas and solutions.

5.  Field-testing of ideas before implementation.

6.  Proven sustainable improvement realization.

The DMAIC roadmap
The principles outlined above are operationalized by the DMAIC roadmap. It employs five phases: Define (D), Measure (M), Analyze (A), Improve (I) and Control (C). The roadmap guides, helps in asking the right questions, prescribes when certain tools and techniques can be used, and forces to organize findings in a structured manner.

1. Define: Select project and project lead, and establish objectives and conditions.

2.  Measure: Make the problem quantifiable and measurable.

3. Analyze: Analyze the current situation and make a diagnosis.

4. Improve: Develop and implement improvement actions.

5. Control: Adjust the quality control system and close the project.

Target audience

Managers and professionals that have business improvement as core responsibility and interest:

–   Operational Excellence professionals (a.o. Lean Six Sigma Green and Black Belts); effectively improving processes and organizational problems is a full-time dedication in many organizations nowadays. Mastering the comprehensive Lean Six Sigma methodology is a prerequisite for adequately doing so.

–   Process and project managers; evidence-based, data driven, and sustainable process improvement is vital for the well- functioning of any organizational domain, regardless of sector or industry. Having a profound understanding of the concepts for doing so is regarded a 21st century prerequisite to be effective in change-oriented business functions.

–   Business and senior managers; regardless of their functional focus, the ability to recognize, install and lead process improvement initiatives is vital for continuous improvement and ongoing business innovation.

–   Other managers and professionals; everyone within an organization that is confronted with processes, the problems that can emerge there, or the ineffective execution of these processes.


Scope and constraints

The premier focus of Lean Six Sigma is to improve operational performance by improving repetitive processes. Thereby Lean Six Sigma is unique, but not without complementarity.

1.  First, the capability to understand and sustainably improve processes allows for optimal decision-making related to process automation opportunities, optimal design of business intelligence monitoring solutions and effective deployment of data science capabilities.

2.  Second, Lean Six Sigma is a comprehensive methodology that enables business process management in organizations. It provides powerful instruments and guidelines for process owners to, besides manage, optimize processes.

3.  Finally, Lean Six Sigma is a methodology (i.e. a collection of principles and powerful (statistical) techniques to make data- based decisions) that are traditionally deployed in structured project formats. For a methodology to be accepted and adopted, appropriate deployment structures that fit existing organizational ways-of-working should be designed, either more or less iterative (e.g. Agile Scrum) or collaborative.