This book presents results from a major European research project - Value Improvement through a Virtual Aeronautical Collaborative Enterprise (VIVACE) - on the collaborative civil aeronautical enterprise. The VIVACE project spanned four years and included 63 partners from multinational companies in 11 European Union countries. The aim of VIVACE was to enable the Virtual Product concept in a collaborative environment through design, simulation, and integration, starting from the early phases of aircraft conception. In this context, the Virtual Product refers to all components that comprise an aircraft - the structure, the systems and the engines. The project contributes to the following strategic objectives derived from the 2001 report ''European Aeronautics: A Vision for 2020'': halve the time to market for new products with the help of advanced design, manufacturing and maintenance tools, methods, and processes; increase the integration of the supply chain into a network; and, maintain a steady and continuous reduction in travel charges through substantial cuts in operating costs. The book structure follows the phases of a generic design cycle, beginning with chapters covering Multidisciplinary Design Optimization (MDO) issues at initial design stages and then gradually moving to more detailed design optimization. The MDO applications are ordered by product complexity, from whole aircraft and engine to single component optimization. Final chapters focus on engineering data management, product life cycle management, security, and automated workflows. Inspired and verified by real industrial use cases, the innovative methods and infrastructure solutions contained in this book present a radical step forward toward the advancement, industrialization, and standardization of the MDO concept. Researchers and practitioners in the field of complex systems design will benefit from the extensive research presented in this important book