Development of complex products and large systems is a highly interactive social process involving hundreds of people designing thousands of interrelated components and making millions of coupled decisions. Nevertheless, we have created methods to study the development process, identify its underlying structures, and critique its operation. In this article, we introduce three views of product development complexity: a process view, a product view, and an organization view. We are able to learn about the complex social phenomenon of product development by studying the patterns of interaction across the decomposed elements within each view. We also compare the alignment of the interaction patterns, between the product, process, and organization domains. We then propose metrics of product development complexity by studying and comparing these interaction patterns. Finally, we develop hypotheses regarding the patterns of product development interactions, which will be helpful to guide future research.INTERNATIONAL CONFERENCE ON ENGINEERING DESIGN ICED 01 GLASGOW, AUGUST 21-23, 2001Center for Innovation in Product Development