The application area of the collinear stiffness value (CSV) developed for the static case [1, 2] can be extended to dynamic characteristics of the mechanical system modeled as a massive rigid body (platform) on elastic supports in a current configuration [3]. Here, this approach is applied to evaluation and optimization of the dynamic stiffness of undamped systems using a modified CSV index named the dynamic collinear stiffness value (DynCSV). The minimal value of the DynCSV is used for limitation of the machine and robot workspace and frequency bandwidth. The most important aspect of the proposed approach is that it allows...