The campaign is the highest layer in the Integrated Content Review object hierarchy. The project is the second layer in the object hierarchy and the asset is the third layer. In fact, an asset is the basic unit of work — a work item — in the Integrated Content Review workflow.
Multiple levels of project nesting are supported.
Assets are actively managed through review cycles and drive all statuses in the campaign. For example, if an asset is late, the status of the parent campaign automatically becomes red. If all the constituent assets of a campaign are on time or green, the status of the campaign is green. Therefore, the status of a campaign is derived bottom-up instead of top-down.
Team member inheritance
Teams are built in a bottom-up fashion. Team members at any level in the campaign hierarchy include team members from lower levels. In other words, a campaign includes all members of a project. A project, in turn, includes all members of the assets within it.
Additionally, at any level in the campaign, a new member can be added directly to the team list. These new members have no responsibilities towards the campaign, but they receive notifications when statuses change. They also get access to the solution interface so that they can proactively see how the campaign is progressing.
For background information, you can refer to the Integrated Content Review Solution Guide.
Original article at http://blogs.adobe.com/samartha/2011/09/project-and-team-hierarchy-in-icr.html.