1. A method to analyze an electrical circuit design (ECD), the method comprising steps of: a) obtaining simulation data for multiple candidate designs of the ECD, the ECD having associated therewith at least one of circuit variables and circuit performance metrics; b) processing the simulation data in accordance with pre-determined rules to obtain characteristic data of the ECD and to determine a characteristic value of the ECD, the characteristic value of the ECD depending on the at least one of circuit variables and circuit performance metrics; c) processing the characteristic data of ECD to determine a statistical uncertainty of the characteristic value; d) determining if the statistical uncertainty of the characteristic value is outside a pre-determined range; and, e) only if the statistical uncertainty of the characteristic value is outside the pre-determined range, obtaining further simulation data for further candidate designs of the ECD to add to the simulation data and repeating steps (b) through (d).