This text covers activities which take place at the conceptual and specification level of the design of complex multichip systems. These activities include the formalization of design knowledge (information modelling), tradeoff analysis, partitioning and decision process capture. ll of these functions occur prior to the traditional CAD activities of synthesis and physical design. Inherent in the design of electronic modules are tradeoffs which must be understood before feasible technology, material, process and partitioning choices can be selected. The lack of a complete set of technology information is an especially serious problem in the packaging and interconnect field since the number of technologies, process and materials is substantial and selecting optimums is arduous and non-trivial if one truly wants a balance in cost and performance. Numerous tradeoff and design decisions have to be made intelligently and quickly at the beginning of the design cycle before physical design work begins. These critical decisions, made within the first 10% of the total design cycle, ultimately define up to 80% of the final product cost. This work lays the groundwork for concurrent estimation level analysis including size, routing, electrical performance, thermal performance, cost, reliability, manufacturability and testing. It should be useful both as a reference for system designers and as a text for those wishing to gain a perspective on the nature of packaging and interconnect design, concurrent engineering, computer-aided design, and system synthesis.