The Diagrams application provides a tool for removing old document session files from a project. It is available from the menu Admin Tab > Admin Tools > Project Maintenance and can be used when the Keep session files setting (KEEP_SESSION_FILES) in Diagrams Options is set to False. After selecting it from the menu, the dialogue window is opened and provides the possibility to select the document types to clean:

After clicking OK the following confirmation dialogue is displayed:

After clicking the Yes button all old session files connected with DB elements (of selected types) existing in the current MDB are removed. Only the files that are related with the most recent version of each element will be kept. Files that are not connected with any SCDIAG, SCTEMP or SCSTEN from the current MDB are not considered to avoid accidental deleting of important files.