By assigning a group to a user, the user will inherit all privileges that are currently assigned to the group.
From the Setup menu, select Security Manager.
Or, click the 
Security Manager icon on the Setup toolbar.
Click the blue Users tab in the upper left corner of the screen. The list of existing users will display in the left pane of the screen.
To add an existing user to a group, click on the User ID in the left pane.
Click the Groups tab at the bottom of the screen. The list of existing groups will display in the lower section of the screen.
Click the checkbox next to each group that will be assigned to the user.
After all appropriate groups, privileges, and reports have been assigned to a specific User ID, continue adding and changing users, or save the completed user.
When finished, click the Save button.
Click the 
Exit icon in the upper right corner to exit the application.
Add Variance Categories to a User