The advisory locking model provides strong support for collaboration through the use of non-exclusive locks. With the advisory locking model, multiple users can check out the same revision for editing by obtaining a non-exclusive lock on check out. All the locks on a revision are shown in real-time in all Windchill RV&S clients that have the applicable Sandbox or project view open. Users are aware of potential changes from other users and can make informed decisions about their own changes. This minimizes potential conflicts that need to be resolved through merging at check in. The first user to commit changes to a revision checked out by multiple users creates the next sequential revision on the branch (assuming the checked out revision was the tip revision). Subsequent checkins by other users require a resync and merge of the previously committed changes into their working files before they are checked in to the repository.