The Work Breakdown Structure (WBS) project is shown in the dropdown at the upper left-hand corner of the Drawings and Reports task window, next to the Permission Group drop-down. It shows the current active project.
In the Common task, you can create new WBS items and projects or edit existing ones. See the Common Help.
You use projects in conjunction with publishing. The active project must be set before using the Final Publish command on the SmartPlant menu. Project mode is not supported in Integration, so Final Publish is not available.