1. A method for converting a process-specific schematic of an analog circuit to a process-independent schematic of the analog circuit, comprising: receiving a parameter value for a device parameter of an analog device defined in a process-specific schematic; for the device parameter: selecting a shadow parameter from a process-independent schema library; and deriving, based on the parameter value, a shadow parameter value for the shadow parameter; storing, in the process-independent schematic, a definition of the analog circuit; wherein the definition of the analog circuit includes data that represents the analog device and data that specifies one or more shadow parameters for the analog device; wherein the one or more shadow parameters includes the shadow parameter; and wherein the definition of the analog circuit further includes data that specifies (1) the shadow parameter value; and (2) an association between the shadow parameter value and the shadow parameter; wherein the process-independent schema library contains a corresponding shadow parameter for each device parameter of each analog device defined in the process-specific schematic; wherein the method is performed by one or more computing devices.