How to improve your company's performance with the Change Management Foundation.

We recently had a problem with the motivation of our team after a reorganization. Because of the changes in processes and responsibilities, many people simply did not understand what was expected of them, and this had a big impact on results. Then our director decided to introduce a new approach to change management. We started by running a training session for department heads. It helped a little, but I feel like more could have been done to make it go even better. Maybe someone has experienced something similar?