This paper has discussed development and implementation of spreadsheet-based decision support tools for modeling and solving blending problems in a large-scale brass factory in Turkey. The user interfaces have been designed in Microsoft Excel which is linked with Lingo modeling language and optimizer. One decision support tool was developed from a single-blend LP model and has been in use at the foundry; it is run several times a day by foremen to obtain optimal raw material quantities for melting operations. That the users were foremen without any engineering and optimization background posed a serious challenge to produce a decision support tool that is easily applicable at the foundry, for which spreadsheet interfaces have produced an effective solution. The paper has elaborated on difficulties faced in the development and implementation and their solutions as well as design of the interface. A similar tool has also been developed for master production planning, which has not been put to use yet. Issues have been discussed regarding its integration into the production planning system and its relationship with the single-blend tool. (C) 2008 Elsevier Ltd. All rights reserved.