Numerical modeling of sintering by continuum mechanical simulations is successfully applied today to predict e.g. the distortions developing during sintering. Several examples that demonstrate the possibilities of such simulations especially for industrial applications have been published recently. However, there are still open questions regarding the influence of grain rearrangement, crack formation and anisotropic starting configurations (e.g. due to prior compaction). By using the Discrete Element Method the sintering process can be investigated on a more fundamental mesoscopic scale. This method also considers effects due to particle rearrangement or anisotropic configurations as well as crack developments automatically. Their influence on various macroscopic properties like densification rate and viscosities is studied. Suggestions how to use these insights to improve existing continuum mechanical models are given.