Set write permissions based on user?

Sorry, I thnk that I didn't ask the question clearly.

The enhancement request is to allow DxDesigner to open a project without needing any special permissions.  I understand that at present, this is not possible.

This question is to ask what permissions are needed; e.g. is it only 1 file that needs read-write access, or every single file in the project folder? (I seem to remember that in DC, only the .PRJ file needs to be writable).  Our current solution is to grant all users full read-write access to all project and design documentation

Additionally, if only the minimum permissions are given, does the design open only read-only?  (I'm suspect that with concurrerncy and server, that it is actually the server that does the design changes, so even if the user doesn't have write access to the project database, the server will still make changes when the user moves things)

I searched for xDM on the Mentor website, and the only results were for xDM Library Management (DMS).  We already have a very comprehensive component management system, and DxDatabook loads it's libraries from that.  We don't have any access problems with libraries.

Is there a different xDM that isn't on the Mentor website?  Are there details available?  Why can't DxDesigner use windows file permissions, like any other windows program?  Will xDM allow us to open a design backed-up on a DVD?

In my company, engineers are assigned to projects, and assigning them to a project grants them write permissions on the whole project.  What we would like is that engineers not directly working on a project might be able to open the schematics of that project, without having full project access permission.  e.g. to look at the schematics, or to copy parts of circuitry already designed in another project.