Abstract-Recent research has shown that tests generated without taking process variation into account may lead to loss of test quality. At present there is no efficient device-level modeling technique that models the effect of process variation on resistive bridge defects. This paper presents a fast and accurate technique to achieve this, including modeling the effect of voltage and temperature variation using BSIM4 transistor model. To speedup the computation time and without compromising simulation accuracy (achieved through BSIM4) two efficient voltage approximation algorithms are proposed for calculating logic threshold of driven gates and voltages on bridged lines of a fault-site to calculate bridge critical resistance. Experiments are conducted on a 65-nm gate library (for illustration purposes), and results show that on average the proposed modeling technique is more than 53 times faster and in the worst case, error in bridge critical resistance is 2.64% when compared with HSPICE.Index Terms-Resistive bridge fault, fault model, manufacturing test, process variation.