Project Permissions feature allows project managers can directly control the permissions on their own projects. These permissions can be controlled by category permission called "Manage Basic Project Security". This is a new feature and exists only in Project Server 2010.
By default, the following groups have the Manage Project Security permissions enabled.
- Portfolio Managers
- Project Managers
NOTE: In default Project Server 2010 instance, Administrators group is based on My organization category; Portfolio Managers group also based on My Organization category; Project Managers group is based on My Projects category.
You can enable this permission to Administrators and Project Managers. Depends on your organization needs, you may enable or disable this permission on Portfolio Managers group.
Please read the tutorial How to manage project permissions from PWA