A general systems approach is applied to modeling of multi-stage industrial crystallization from solution. The model integrates spatial, time and component hierarchies that co-exist in a multi-phase and multi-component system. As strict multi-phase boundaries cannot be determined the concept of relative densities of phases and components based on the total system volume is used. The model has simulated both evaporative and cooling crystallization considering the effect of the impurities on the quality of the crystal product and has been verified using industrial data. The generality of the model allows simulation of new processes and variants of existing batch crystallizations. (c) 2008 Elsevier B.V. All rights reserved.