Models and components have become an indispensable part in the development of embedded systems. They reduce the complexity of embedded systems and provide a formal ground on which analysis and synthesis are performed. ProCom is a component model intended for embedded systems design. It has been developed within PROGRESS, a large research project aiming to provide component-based techniques for the development of embedded systems. The behavior of ProCom components is specified in the REMES modeling language. REMES is used for specification for both functional and extra-functional behavior of the components (timing, resource usage, reliability etc.). Without proper tool support, the use of models and components is very difficult. Such tool support is typically integrated in an Integrated Development Environment (IDE), which is simply a framework containing a programming environment. This thesis provides an implementation of a GUI for component behavior modeling based on REMES as a plug-in for the Progress IDE.