The scientific method is defined in Wikipedia like below:
The scientific method is an empirical method of acquiring knowledge that has characterized the development of science since at least the 17th century. It involves careful observation, applying rigorous skepticism about what is observed, given that cognitive assumptions can distort how one interprets the observation. It involves formulating hypotheses, via induction, based on such observations; experimental and measurement-based testing of deductions drawn from the hypotheses; and refinement (or elimination) of the hypotheses based on the experimental findings.
When I read the definition of Scientific Method first time, I thought that the process of Lean Six Sigma is very similar to the Scientific Method because the Lean Six Sigma frameworks such as DMAIC and DMADV are an empirical method.
Although the Lean Six Sigma can be said as a Scientific Method, it is hard to accept the “experimental and measurement-based testing of deductions” in a Lean Six Sigma project sometimes. Even the experimental finding met the hypotheses, sometimes we could not accept the deduction when it incurs additional cost and/or work loads. The problem is not the deduction, but the mental resistance in our mind.
Sometimes I see a bad case of Lean Six Sigma project which already has a conclusion from the beginning. The hypotheses, the measurement-based testing and other elements in the Scientific Method are used just to verify the conclusion. Further worse, the project could manipulate the data when the deduction drawn from the hypotheses doesn’t match with the conclusion.
The bad case typically can be seen in a decision making tool such as Pugh Matrix, AHP, and Concept FMEA in a project conducted by a busy manager with a pressure of cost saving and short lead-time. The Lean Six Sigma framework could be used just to create a presentation document.
We must accept the deduction drawn from the Scientific Method or Lean Six Sigma project. The acceptable deduction must be drawn from the reliable and trustful process. The purpose of Lean Six Sigma training is to master such reliable and trustful process.
I explain Lean Six Sigma as a Scientific Method in my Green or Black Belt training class with hoping that the Lean Six Sigma will change a way of doing our job from arbitrary to scientific.