To help with data accuracy related to nominal voltages within the NMS model an iterative approach is used to set the data used by power flow services for the power flow analysis. It is expected customers will populate the NETWORK_COMPONENTS.VOLTAGE column with as accurate data as possible from the GIS, this data will be used at power flow services startup to establish a starting point for the nominal voltages. After the initial load of the device attributes power flow services begins a process of refining the nominal voltage data by tracing from key devices using the "As built" topology model. Since voltages are configured at Equivalent Source objects and Power Transformers power flow services can use these voltages to cross reference the voltages that were set in the NETWORK_COMPONENTS table to check for mismatches. For example if the source voltage is 138kV power flow services knows that everything between that point and the downstream Power Transformer needs to be 138kV, once the tracing hits a downstream transformer it checks to see what the secondary side nominal voltage is for the transformer. If the secondary side voltage was determined to be 12.47kV it then understands that everything downstream of the transformer should be 12.47kV until another transformer is reached or the end of the network is reached. During this process power flow services checks the voltage for each device that was read from NETWORK_COMPONENTS against what was found during the tracing and adjusts accordingly in power flow services memory. If power flow services Model debug is enabled an associated message will also be placed in the power flow services log file to alert an admin that an incorrect voltage was found in the NETWORK_COMPONENTS table and should be changed. It is critical that customers ensure an accurate voltage is configured for Equivalent Sources and Power Transformers that get populated in tables PF_SOURCES and PF_XFMRS respectively. The limitation of this processing is the tracing does not currently refine areas that are nominally de-energized or set as construction pending, so care must be taken to ensure the NETWORK_COMPONENTS table is populated with accurate voltage data. The voltage data populated within the NETWORK_COMPONENTS table should always be in terms of "Line to Line" voltage even if the object is single phase, all power flow services model tables have this same requirement (for example, PF_SOURCES, PF_XFMRS, and so on).