Method for assessing fatigue damage and/or wear damage to a rotating tool comprising motor means, a transmission comprising a plurality of components, and a terminal member, said terminal member being capable of being driven in rotation and/or in translation by said motor means via said transmission, said method comprises at least: - a step of determining at least one information representative of the torque applied to said transmission; - a step of determining at least one information representative of the angle of rotation of said transmission; - a step of determining, as a function of said torque and of said angle of rotation, a fatigue damage and/or a wear damage to at least one of said components, characterised in that said fatigue damage and/or said wear damage being proportional to the amount of work provided by said tool to drive the motion of said terminal member during the life of the tool, this amount of work being calculated for at least one component by the integral of the torque transmitted by this component as a function of the angle of rotation of this component, or said method being carried out in successive cycles of use of said tool, said method comprising at least: - a step of determining, during each of said cycles of use and as a function of said torque and of said angle of rotation during the cycle considered, at least one fatigue damage per cycle and/or one wear damage per cycle to at least one of said components for the cycle considered; - a step of determining a fatigue damage and/or a wear damage to said rotating tool or to said at least one component, each corresponding to the accumulation of said fatigue damages per cycle and/or to the accumulation of said wear damages per cycle over all cycles considered for said at least one component, said step of determining said fatigue damage to at least one of said components during a cycle comprises carrying out, according to a predetermined angular period during or after said cycle: - a step of determining the value of the stress Ci applied to said component; - a step of determining, using the stress Ci, the number of cycles NCi before failure that can be carried out by said component, taking into account a predetermined mathematical law, specific to the material from which said component is made, expressing the stress Ci to which the component is exposed as a function of the number of cycles NCi that can be carried out by said component exposed to this stress before it fails; - a step of determining an elementary fatigue damage as being equal to 1/NCi. - a step of determining at least one information representative of the torque applied to said transmission; - a step of determining at least one information representative of the angle of rotation of said transmission; - a step of determining, as a function of said torque and of said angle of rotation, a fatigue damage and/or a wear damage to at least one of said components, characterised in that - a step of determining, during each of said cycles of use and as a function of said torque and of said angle of rotation during the cycle considered, at least one fatigue damage per cycle and/or one wear damage per cycle to at least one of said components for the cycle considered; - a step of determining a fatigue damage and/or a wear damage to said rotating tool or to said at least one component, each corresponding to the accumulation of said fatigue damages per cycle and/or to the accumulation of said wear damages per cycle over all cycles considered for said at least one component, said step of determining said fatigue damage to at least one of said components during a cycle comprises carrying out, according to a predetermined angular period during or after said cycle: - a step of determining the value of the stress Ci applied to said component; - a step of determining, using the stress Ci, the number of cycles NCi before failure that can be carried out by said component, taking into account a predetermined mathematical law, specific to the material from which said component is made, expressing the stress Ci to which the component is exposed as a function of the number of cycles NCi that can be carried out by said component exposed to this stress before it fails; - a step of determining an elementary fatigue damage as being equal to 1/NCi.