Why should I lock my VCM session?
It should be seen as a best practice process to lock a VCM Session.
The reason for this is that when running a VCM Promote, Rebase or Replicate session, there is a clear expectation that the target view state remain unchanged for those files, CRs etc which are participating in the merge. If these change before the session is committed, then the actual commit will fail and throw exceptions.
To ensure that the target state is unchanged when a VCM compare is run, the administrator should lock the target items that contribute to differences and should break other user locks if necessary during the session.