The success of project depends on many factors. First is support and commitment to the DMAIC process from the manager(s) in the area(s) affected by the project. Second, you need to build a cross-functional team representing the various interests that come into contact with the area affected by the project.
From there, your success is most dependent on how well you can help the team be effective at working together and following the DMAIC process. To help you with this, our training has a section devoted to Effective Teaming and we include our manual on Effective Teaming with your purchase.
The technical tools will help you come up with the best solution most efficiently, but we have frequently had feedback from our Black Belts that they found the Effective Teaming section to be most critical to their success.