While many other reasons are put forward for what have enabled one deployment to be more successful than another, statistics seem to indicate that good, experience implementation consultants almost always ensure success. This is the one ingredient that if it is omitted almost always lead to delays, tentative deployments and missed commercial targets.
Many of these independent consultants can be found and I would be happy to recommend these to interested parties. It is impossible to single out any specific consultant, but as an example one could reference Mark Guthrie (partner in consulting company

I think that these experienced program managers with an ability to grasp the uniqueness of MMT projects are often overlooked in planning projects. Results seem to indicate that this is the biggest mistake than can be made.