Powder mixing is one of the most important pharmaceutical manufacturing operations. Computation methods are required to transform mixer design and scale-up from art to science. Due to an increase in the computational power and the development of graphics cards, the discrete element method is becoming a widely-used technique. For an industrial granular mixer, it is demonstrated that a smart simulation strategy together with a highly efficient code can reduce the simulation time. The good agreement between simulation and measurement data confirms that the simulation strategy can be applied to the product development.