The impact of conceptual design is well known in the context of complex engineering systems, changes made during later design phases can severely impact the performance of the design process and the quality of the final outcome. This book describes a set of guidelines in an integrated methodology to deal with the shortcomings of current collaborative design environments, identified from both literature and survey findings. The proposed integrated methodology is based on the premise that the design properties can emerge after a proper identification of the system-level objectives, and consequent assessment of their impact at the subsystem level. It is an iterative process, with four clear stages, that monitors the evolution of objectives, requirements, system states, and subsystem design models. Two tools were developed to implement some of the guidelines behind the integrated methodology as an illustration of possible applications: an agent-based predictive decision support tool, and an integrated concurrent environment allowing the assessment of interactions between subsystems with the help of a dynamic Design Structure Matrix.