Predicting the bulk solid’s behaviour and extracting information which cannot easily be measured experimentally are key benefits of Discrete Element Method (DEM) simulations, such as Ansys Rocky DEM. However, the quality of the prediction depends on the calibration of the simulation.  Meaningful DEM results require best-practice calibrations and an understanding of the different flow regimes of bulk solids. To achieve this, the following article aims to be a guideline for engineers. For further reading: An engineers guide to materials calibration when modeling bulk solids