Valve stiction is a well known villain in process industry. Quantifying this valve damage is essential to ensure plant stability and profitability. The scope of this work is to propose a new method to compute valve stiction parameters, using a two parameter model, using only routine operating data. The proposed method uses global optimization to evaluate loop and plant parameters. Combining the proposed procedure with an efficient global optimization algorithm, the mean computation time for each valve was about 5 minutes. The method was applied in both simulation and industrial valves, providing reliable results, with relative errors smaller than 3% in all parameters.