In this paper, we discuss some requirements for future CASE (Computer Aided Software/Systems Engineering) environments. These requirements include increased modifiability and flexibility as well as support for task and agent models. We claim that they can only be addressed by developing more powerful representation and modeling techniques. As a possible basis for a modeling technique, we propose the GOPRR (Graph-Object-Property-Relationship-Role) data model, which addresses some of these requirements. In addition, a general information architecture for a future CASE environment is outlined. It includes three kinds of models for methodology specification: meta-datamodels, activity (task) models, and agent models. These models are defined using the GOPRR model with some additional concepts for IS development process and agent participation.