It goes without saying that when the Yellow Belt certificates are present to back up project leaders with their Green or Black Belts, the odds of a successful delivery are significantly boosted. While not the sole consideration, this is crucial since it ensures that the project's mandated work is well understood and carried out to enable the most significant potential conclusion.
https://joyrulez.com/blogs/381821/Why-Six-Sigma-Yellow-Belt-Is-a-Life-Changer-Methodology