Many engineering design problems involve complicated physical phenomen a that frequently compel designers to use trial-and-error methods to arrive at a design that can be manufactured. Design methodologies are needed that combine the analytical capabilities available from computers with the reasoning abilities of human experts. The goal of this research is to create an intelligent computer-aided design methodology for mold thermal system design. The proposed design methodology will incorporate optimization techniques and the human decision making process in an interactive computer-aided design and analysis system. The long-term goal of the research is to increase our understanding of the role of computer and human expertise in computer-aided design and manufacturing.