You need the BI Tool permission to delete a visual analysis. However, you can only delete the visual analyses that you create, and not those that have been shared with you, unless you made a copy of the shared analysis, which places a copy in your My Items folder.
When you delete a visual analysis that has been stored in the Visual Gallery, it is not automatically deleted from the Gallery. You must manually remove it from the Visual Gallery.
1. Click Reports in the Navigation Toolbar, and select the BI Toolbox link in the menu.
Visual analyses you created include the icon and the shared analyses you copied include the icon.
3. Locate the visual analysis you want to delete, and click its icon.
4. Click OK in the confirmation prompt.