Does learning Lean directly from the Sensei make a big difference versus taking those professional certifications?
To which I answered as follows:
I don’t know why the word “sensei,” which is Japanese for school teacher, is being endowed here with such an aura. To get started, you should use a consultant who can help you select the right projects to undertake first on your shop floor, organize the team to execute on these projects, and coach them to success.
Certification will do none of that. You should only pursue certification if you are looking for a job and need it as a resume enhancer.
More more details on the value of certification, see Certification Shmertification!
For a review of the Lean body of knowledge and five leading certification programs, see The Lean Body of Knowledge.