Lean Six Sigma

Lean Six Sigma combines the principles of flow and waste removal from the Lean movement with those of evidence-based problem solving found in Six Sigma and this has given rise to the term ‘Lean Six Sigma’.


Lean is an improvement approach to improve flow and eliminate waste that was developed by Toyota. Lean is basically about getting the right things to the right place, at the right time, in the right quantities, while minimising waste and being flexible and open to change.

Lean thinking focuses on what the customer values: any activity that is not valued is waste. If you remove the waste, the customer receives a more value added service. For example, in healthcare this could mean any activity that helps patients get better and / or manages their symptoms and comfort.

In classical Lean there are 3 categories of waste.


Overburden. Typically this is because the process and the resources needed have been poorly designed, planned and allocated by the management


Unevenness. This can be due to unsteady external demand, but can also be created internally, e.g. by batch processing ‘dumping’ a load of work on the next department


Non-value-added work.

The classic 7 Wastes are all Muda

Lean Six Sigma

Many Lean initiatives focus only on Muda. Note that the definitions that are often used in manufacturing have to be re-interpreted for another situation, such as product development.

Six Sigma

Six Sigma is about a well defined approach to problem solving that makes use evidence and statistical testing of hypotheses to make decisions rather than ‘gut-feel’. See Six Sigma.