Concurrent engineering has brought much attention in recent years to engineering design and its impact on issues such as costs, cycle-time, and quality. These issues, coupled with global markets and rapid technology advancements, have created significant need for improved methods and supporting tools for engineering design. To date, advances have focused predominantly on tasks that are well into the latter stages of product development. Advances for early design have been limited. In general, methodologies have taken either a top-down or a bottom-up approach to design, and as such, have virtually guaranteed the continued separation of abstraction and detail during conceptualization. This paper presents an integrated conceptual modeling system that supports a blended methodology from the earliest stages of engineering design. Modeling, synthesis, integration, knowledge capture, and reuse are considered. An example design problem from the domain of power conversion systems is included to demonstrate the utility of the system for technologically sophisticated products.