For making a generic model of planar belt drive systems in Dymola, the project is divided in two steps; First, the Planar Multibody Library (PML), which is built of general components for use in two-dimensional applications such as mass, revolute joint and beam element. Second, modelling of the Scania Belt Drive Library (SBDL) by using the components in the first step and making some new components specially designed for belt drive simulations. Results of the Scania Belt Drive Library are validated against the experimental data and AVL/Timing Drive. Advantages such as the possibility of changing or updating the components equations, start up simulation, being less error prone due to user inputs, and even simulation performance are the major reasons for which the Scania Belt Drive Library has been created. Modelling of a component in Dymola demands deriving the necessary equations of motion for that special component.