Michael Niehaus' Windows and Office deployment ramblings : Automating Long-Running MDT 2010 Tasks
There are a few operations in the MDT 2010 Deployment Workbench that can take a while. We’ve done our best to optimize those processes, but in many cases they will still take a good amount of time to complete. While you could certainly start an operation in one Deployment Workbench and then open another Deployment Workbench so that you can continue working, it would be even better to schedule these long-running tasks so that they run automatically, ideally when you are sleeping and when there aren’t any active Lite Touch deployments going on.
Michael Niehaus' Windows and Office deployment ramblings : Automating Long-Running MDT 2010 Tasks