The InfoSWMM Facility Manager offers the knowledgeable engineer complete control what elements are simulated in her or his model. You can make active or inactivate elements based the type of Network Element, A Network Path, A Mouse Drawn Map Selection, The Domain, A selection set, a DB Query, a Query Set and a Special Query. You can make the simulated network smaller or larger depending on your simulation or calibration requirements. For example, you can have a whole basin network but model only a branch or a subset of the network if you are using the Calibrator or Designer Addons.
via Blogger http://www.swmm5.net/2013/08/infoswmm-and-h2omap-swmm-facility.html