Updating project owning department

Summary

Automatically update tasks when a department change is made on the project header

Content

We are exploring the option of updating the project owning department. We learned the navigation of where to go to update the owning department at the project header level. IE: Edit Project Financial Settings". We also then manually updated the department on each project task. Is there a way to automatically cascade this down to the tasks when it's updated in the header? 

What are the impacts of updating the department on a project? 

Thank you,