In this work we try to reproduce demixing of invasive and non-invasive breast cancer cells, which occur in experiments. The system consists of two particle types which differ either by their potential, or by the strength of the activity of the particles. To investigate the properties of the system a simulation is established where the particle movement is governed by the Langevin equation. The external force is used to model a different stiffness of the particles by two types of pairwise interactions between the particles. Activity is modeled by oriented diffusion, variation in the diffusion step size are used to distinguish the particle types. In the case of different potentials and also in the case of different activity (with equal pair potentials), the system can be tuned such that the invasive particles diffuse to the surface of the ball, which is also recovered in experiments. The clustering of invasive cells and the formation of a hole in the ball could not be observed. But it is not excluded that with further fine tuning of the parameters this effects could happen.