The Duct Sizing utility refines a system after initial placement of a route. Sizing the system before placement is still an important part of the design process, but certain properties like flow and velocity rates can result in resizing of the entire system. Typically, enhancements or design optimizations are minimal as the optimal design is closely approximated during the initial placement phase. The route analysis tool is capable of making substantial changes in system geometry as well as calculating flow and velocity rates for potentially hundreds of components. Insulation and flow rate changes are visible from within the sizing tool. Optimization changes affecting sizing and connectivity are not. The final application of all analysis changes is done when the sizing utility is closed or dismissed, and the system is recalculated automatically The BMECH REBUILD utility changes sizes and maintains connectivity. The Message Center displays a message when the rebuild is complete. If certain components are disconnected during the rebuild, they are detected by the View Disconnects dialog.