A method of operating an electric machine such that an electric tool for an internal combustion engine (ICE) is provided, wherein the internal combustion engine and the electric machine each produce a torque and a hybrid electric vehicle (HEV) drive, comprising determining a size of a of a vehicle operator requested service, determining a minimum power limit and a maximum power limit of the engine, which generate a response to a torque request within a desired period after the torque request, determining a minimum and a maximum electric power limit of the electric machine, using the size of the requested service, the minimum and the maximum power limit of the engine, and the minimum and the maximum electric power limit to determine an upper and a lower limit of the electric auxiliary such that the required Torque ent is provided within the desired time period, and operating the electric machine to provide the electric tool within the upper and the lower limit.