Users without a role or that are not assigned a role in any object will see an almost empty ITP/MDK Repository in which they can do almost nothing. All roles defined by the Administrator are available in all objects. Users are assigned a role per object. So a user can be a manager for one object and a developer for another.
The tab Authorization can be found by opening the Configuration window from the context menu. On this tab the available roles are listed. When a role is selected the button Add allows you to select Users that will be assigned the role.
Be aware that the permissions in the roles add up. For example, if a user is Project manager and a Model developer as well, the user has permission to perform all actions of both roles. It is also possible to assign a role to a user on a global level. This can only be done by the Administrator.
Note
Changing the authorization of a user only takes effect the next time the user logs in.