Process design depends on the accurate understanding of equipment integration and general flows (mass, energy, momentum) across a chemical plant. Process Synthesis, as a fundamental step for achieving the optimal conditions for obtaining a desired artifact, plays an important role in the decision-making for flowsheeting alternatives as well as general cost minimization. In order to link traditional chemical engineering procedures with systems engineering, the present book intends to present synthesis problems alongside important concepts/tools, such as: evolutionary as opposed to only heuristic methods of decision-making and their connection with graphs theory. In this manner, this book studies some benchmark applications from different network structures and outlines the main general necessary steps and methods for process synthesis and suggests the Black-Scholes option pricing formula as a valuable method for cost analysis if risk is present.