This paper presents a practical case where parallelization for multi-core processors can be exploited in Modelica models using OpenMP. Although this parallelization is applied to a particular case and to a particular section in the code, the parallel implementation is straightforward and a gain in speed of around11% is obtained. The particular section in the code is the initial section and the particular case is to consider that the initial section is time consuming and the operations are independent from each other. The particular case is tested in a real dynamic model during the simulation and calibration processes. The most appealing feature of this method is that it is straightforward to implement and that it could be easily adopted by equation-based modelling languages. On the other hand, the process is not automatically performed and the modeller needs to have a minimum knowledge about parallel computing.