Method and apparatus for estimating damage to an object, with at least a first parameter which corresponds to an operational state for the object and at least a second parameter which corresponds to a condition during the operational state being determined by at least one operation measurement, and with such measurement being carried out repeatedly. A total load that is defined by the total influence of the first and second parameters on the life of the object is then calculated. The invention also relates to a method and a system for controlling the use of the object.