The lifetime of a considerable number of satellites is significantly shortened by malfunctions occurring during operational period; therefore, unmanned satellite servicing missions are considered. This paper presents an approach for analyses of various configurations and parameters of manipulator intended for on-orbit servicing. It is based on analytical method used to analyse workspace and singularities of the manipulator mounted on a free-floating satellite, and on numerical simulations of mission-specific manoeuvers (e.g., capture of malfunctioned satellite). The application of this approach to obtain parameters of the manipulator most suitable for defined servicing tasks is presented.