The Scenario-based Engineering Process (SEP) is a novel approach to developing complex systems. SEP builds new application systems through a selection process that groups primitive components into application specific components. The selection of primitive components and the construction of interfaces among components in an application system is currently a tedious manual undertaking. The automation of this process will require a configuration system that can support the complex interactions of the components, the dynamic requirements of users, and the capabilities of providing multiple viewpoints and managing extensive domains. This paper will discuss our work on a configuration system based upon UM-PRS, the University of Michigan Procedural Reasoning System. To support the SEP methodology, we are developing a system, SEFRS, that will use planning techniques for component selection, integrated with semantic understanding techniques for dynamic interface construction, to create a flexible and powerful system engineering environment.