1. A method for designing a circuit comprising a plurality of conductors, the method comprising: selecting a first operating point corresponding to a first circuit application; selecting a second operating point corresponding to a second circuit application; determining a performance difference between circuit operation at the first and second circuit operating points; using the performance difference to compute a factor; applying the factor to resistance values of the conductors, thereby producing modified conductor resistance values; and performing a timing analysis of the circuit using the modified conductor resistance values.