Adobe Analytics offers a robust user permission system. You will need to contact someone with Admin access to your Adobe Analytics (Omniture) instance to enable report builder access for your login account.
(With an Admin account) Login to Adobe Analytics.
On the top-left is the Rail icon (3 horizontal bars). Click on this to toggle open the left-nav if it isn't already visible.
Navigate to Admin > User Management.
Click on the Users tab at the top, or the Edit Users button in the Users section on the page.
Find your Login name in the list and in the "Manage" column on the right, click on "Edit".
In the Access section, you should see two boxes showing a listing of groups and services. Select "Report Builder" and click the "Add" button to move it from the left box to the right box.
Click on Save Changes to save.
If you do not see Report Builder in the box, then either your Adobe Analytics account is not provisioned for Report Builder, or else the account you are attempting to make the change with doesn't have sufficient privileges to do it.