In this paper, we present a tactical supply network planning model focusing on applications in specialty chemicals industry. The model incorporates both, industry-specific aspects such as product transfers, single-sourcing of intermediates or product mix effects on capacity and elements of international trade such as duties, duty drawbacks and currency effects. The model is integrated into a decision support system linking the optimization model developed using ILOG OPL 4.2/CPLX 10.0 to a visual user interface.