If two or more persons within one project are working on the same file at the same time, changes will not be merged live. The file or bodies/ components a person is working on is not locked for the other members. Also every member of the project shoud get a notification when any part (component or body) of the file is going to be changed or updated by another collaborator. Is this is the case parts of the file (components/ bodies) should be locked, so that no conflict can occur.