Modeling and simulation of biotechnological processes enables the quantification of possible process variations. In this way it provides a tool for guiding research towards the most promising directions. The method is shown on the basis of the case study of alpha-cyclodextrin production. The production process was modeled and the model is used to evaluate the potential impact of CGTases with new properties. Sensitivity analyses show that yield and selectivity are the crucial parameters. Reaction time has only limited impact and substrate concentration has to be above 20%. The use of thermostable enzymes provides some energy savings. Furthermore, the effect of new CGTases leading to a modified downstream processing was assessed. (C) 2004 Elsevier Inc. All rights reserved.