A method of operating a turbine, the method comprising the steps of: gathering thermal profile data for a blade (5, 9) while the turbine operates at different operating temperatures; gathering measured creep data for the blade (5, 9) while the turbine operates at the different operating temperatures; gathering operating conditions data for the turbine while the turbine operates at the different operating temperatures, including at least a rotational speed of the turbine; based on the rotational speed of the turbine at the different operating temperatures, determining the mechanical stress applied to the blade (5, 9); given the thermal profile data for the blade (5, 9) and the mechanical stress applied to the blade, calculating predicted creep rate data for the blade (5, 9) while the turbine operates at the different operating temperatures; calibrating the calculation of the predicted creep rate data with the measured creep data for the different operating temperatures; and calculating calibrated creep rate data for the blade (5, 9) at the different operating temperatures; wherein the different operating temperatures include at least a first operating temperature and a second operating temperature; and given the calibrated creep rate data for the blade (5, 9) while the turbine operated at the first operating temperature and the calibrated creep rate data for the blade (5, 9) while the turbine operated at the second operating temperature, determining whether operating the turbine at the first operating temperature or the second operating temperature is more economically efficient, wherein the step of determining whether operating the turbine at the first operating temperature or the second operating temperature is more economically efficient includes the step of calculating the predicted revenue data for the turbine at the first operating temperature and the second operating temperature; the predicted revenue data comprising data concerning revenue that the turbine earns while operating at the different operating temperatures. gathering thermal profile data for a blade (5, 9) while the turbine operates at different operating temperatures; gathering measured creep data for the blade (5, 9) while the turbine operates at the different operating temperatures; gathering operating conditions data for the turbine while the turbine operates at the different operating temperatures, including at least a rotational speed of the turbine; based on the rotational speed of the turbine at the different operating temperatures, determining the mechanical stress applied to the blade (5, 9); given the thermal profile data for the blade (5, 9) and the mechanical stress applied to the blade, calculating predicted creep rate data for the blade (5, 9) while the turbine operates at the different operating temperatures; calibrating the calculation of the predicted creep rate data with the measured creep data for the different operating temperatures; and calculating calibrated creep rate data for the blade (5, 9) at the different operating temperatures; wherein the different operating temperatures include at least a first operating temperature and a second operating temperature; and given the calibrated creep rate data for the blade (5, 9) while the turbine operated at the first operating temperature and the calibrated creep rate data for the blade (5, 9) while the turbine operated at the second operating temperature, determining whether operating the turbine at the first operating temperature or the second operating temperature is more economically efficient, wherein the step of determining whether operating the turbine at the first operating temperature or the second operating temperature is more economically efficient includes the step of calculating the predicted revenue data for the turbine at the first operating temperature and the second operating temperature; the predicted revenue data comprising data concerning revenue that the turbine earns while operating at the different operating temperatures.