In recent years, there has been significant attention given to improved methods and tools for engineering design. While advances for the latter stages of design have been impressive, this has not been the case for the early stages of design. In general, advances have provided for either a top-down or a bottom-up approach to design; ignoring the requirements for both abstraction and detail in a concurrently engineered development process. This paper describes an integrated conceptual modeling framework for a blended methodology. The utility and extensibility of this framework are considered in discussion and by way of examples.