improvement

This is in one way the difficult part, but on the other hand, when problems and root causes are clear, it is maybe also not too difficult to implement needed improvements, just because of a very simple reason: if something does not work well, it opens seeing opportunities to do it in another, never explored way before... 

And this is where the challenge starts: everybody having its own opinions and not always automatically supported by the right skills and/or experience.

So the most challenging is most likely the Change Management process, just to overcome typical cultural behaviors, like NIMBY (not in my backyard) and/or NIH (not invented here) syndromes. 

In all cases, in this phase the most critical factor is to have the absolute top experts joining the task force to make the improvements happen. Business Process Owners, (Master) Black Belts, Continuous Improvement Leaders, Change Managers, the Process End Users, Application Experts, Data Analysts and Data Scientists