To migrate a file from the submissions queue into active project workflow, click on the Submissions link the sub-menu. Click the Settings (the "wrench" icon) button on the file card for the desired file to view the File Detail Page.
In the top-right of the File Detail Page, click on the pull-down list next to the blue View icon. Select the Migrate menu option and then search the network for and specify the primary owner of the file in your company's development workflow.
