The Stage Manager is another subset of the role of Project Manager, this one with the responsibility of managing a particular project stage.
Common examples come from the IT domain, i.e. Testing Project Manager and/or Implementation Manager, with responsibility for the testing and implementation stages.
The Stage Manager may be particularly skilled and experienced in delivering parts of the project lifecycle and therefore will be called upon from across the organisation.
In organisations where there are projects and programmes which are repetitive in nature, for example there are many iterations of a product throughout continuous lifecycles, the Stage Manager will be particularly experienced in delivering the project through parts of the lifecycle.