Abstract: An electrical design system is described which integrates many analysis and synthesis tools in an environment of top-down circuit layout. The system allows electrical design in numerous technologies, including nMOS, CMOS, bipolar, printed circuit boards and others. Technologies and analysis or synthesis tools may be added or deleted easily, and different technologies may be employed in a single design. The system includes a database manager which maintains all information regarding the design of the circuit, and which is accessed by all of the analysis and synthesis tools to enable them to examine and modify the design.The database itself is structured as a network of electrically connected and geometrically described components. Each component in the database is considered a node, and connections among components are considered as arcs. Changes are permitted only to nodes, and constraints are imposed only upon arcs.