This paper presents the methodology to perform the sensitivity analysis for impedance-based fault location methods, considering power distribution systems and the presence of distributed generation. The proposed methodology helps to determine the power distribution system model parameters, which significantly affect the fault locator performance. Having identified such parameters, the next step is to perform improvement strategies and compensations of the fault locators aimed to develop more robust locating tools. As result of the proposed methodology, a set of critical parameters of the power system model is here identified.