Modern microelectronic technology enables implementation of a complete complex information processing system on a single chip. Progress in microelectronic technology is extremely fast and is outstripping the system designers' abilities to make use of the created opportunities. The complexity and quality of the microelectronics-based systems as well as their design and production cost and time tend to be more limited by the design methods and tools than by the microelectronic technology. Substantial improvement can only be achieved through development and application of a new generation of more suitable design paradigms, methods and tools. In this paper, some new opportunities and difficulties related to the system-on-a-chip technology are considered, the nature of the complex system design problems is analyzed and a quality-driven system design methodology is proposed and discussed. Some important implications are also considered of the modern quality concepts for design modeling, design exploration techniques and tools, design decision making, design reuse and design validation.