want to develop a document sharing system and this is for software specific requirement and I want to find out the assumptions and dependencies for picture posted above

We want to develop a document sharing system such that group members can collaborate on the same documents without causing inconsistencies. There are three types of users in system: Super User (SU), Ordinary User (OU) and Guest (GU) SU this update membership maintain a list of taboo words unlock any locked document process complaints about OU's have all privileges reserved for OUs inside any group . OU create new document(s), the creator of a document is the owner of the document and can invite other OUs to update it, and decide if the document is open to the public (can be seen by everyone), restricted (can only be viewed as read-only by GU's and edited by OU's). shared (viewed edited by OU's who are invited) and private an OU can accept or deny the invitation(s) placed by other OUs for their documents lock a shared document for updating, only one OU can lock a document successfully, the system should indicate which OU is updating the document update a successfully locked document, and then assign a unique version sequence number and remember who and when makes the updates unlock a shared document locked by him herself .file complaints to the owner of a document about other OUs'updates or to the SU about the owner of the documents as the owner of a document deal with complaints filed by other OUs (remove some OUs who were invited before) unlock the locked documents she owns that is being updated by others search own file(s) based on (partial) keyword search information about other OUs based on name and/or interests. . have all privileges for GUs GU read open document(s), retrieve old version(s) of open document(s) and complains about those documents. send suggestions to SU about taboo words