While working on the SharePoint implementation I encountered a problem with delete permissions.
SharePoint document libraries do not allow you to set permissions in such a manner to allow users editing/deleting only their own documents. Similar feature exists for other lists like team discussions and blog comments but it does not exist for document libraries!?
The lack of this feature is not so problematic for editing items because users can be easily controlled with approval workflow in place. But how can you control if someone wants to delete a document?
As a site owner you have two options:
1) You can setup an alert that will inform you upon deletion; you can recover a deleted document from the recycle bin
2) If you prefer more control, there is one alternative. Revoke all delete permissions for your users. Create a Delete workflow. This workflow should work similar to the default approval workflow. User should initiate workflow instead deleting a document. After “approval”, document will be deleted.