If you haven’t already heard about this new feature then head on over to the Project blog at https://blogs.office.com/2015/06/19/resource-engagements-coming-soon-to-project-2016/, where Julie Kohler introduces the resource engagements feature and gives more information on what this does. Here is a taster:
This was also covered in the Ignite session - Microsoft's Vision and Roadmap for Work, Project, and Portfolio Management - https://channel9.msdn.com/Events/Ignite/2015/BRK2136 at about the 49 minute mark from Mike McLean if you want a video demo.