Tight time and cost constraints force chemical process industries to continuously reduce their experimental effort during chemical process development and to facilitate the application of model-based process technology. Nevertheless, the effort of setting up a detailed mathematical model for a chemical process remains still high due to the large variety of chemical process units and physical phenomena as well as increasing requirements on the sophistication of models. To overcome this modeling bottleneck considerable effort has to be spent with the systematization of process models, the formalization of their representation, and the development of knowledge-based software tools. This contribution deals with the modeling environment MODKIT, which supports the systematic development, maintenance, and reuse of chemical process models. It will be shown, how informal textual or graphical information defining requirements on models can be specified by use of MODKIT. Furthermore, computer-aided means for the structural and behavioural description of chemical processes, as well as an approach for the support of the workflow of model development will be described.