Since projects can be linked to other documents in many different ways, there are a host of varied privileges which might impact a user's ability to interact with project-related functionality. However, there are only two module privileges specifically related to projects:
Allows users to create and edit projects.
Allows users to view projects.
To assign privileges to an xTuple system user, follow this path: .

Once you open a user record, navigate to the tab and identify the module where the privileges you want to assign are located. You can assign and also remove user privileges in this way.