Application.SaveForSharing Method (Project)
Saves a local copy of the active project for sharing, to make changes and then merge with the Project Server copy.
The SaveForSharing method is available in Project Professional only. The original project on Project Server is marked as saved for sharing. The local copy of the project file can be modified and the changes merged with the original Project Server copy when you use the Save As command or the FileSaveAs method. If you try to reopen the Project Server copy before merging the local copy, Project Server disables sharing and prevents merging changes from the shared copy to the server.