This book presents an operational tool for decision making under uncertainty in any engineering design. It synthesizes classical decision making methods, such as multi-attribute utility theory, analytic hierarchy process with game theory and quantum decision theory. It demonstrates the implementation of the value driven design philosophy in the engineering design framework.Value, related to the designed system's capabilities and lifecycle cost, is used to compare different alternatives through the appropriate value model. Game Theory as an optimization tool is used to successfully address the stakeholders' preferences in a functional outcome-focused way. A Quantum-based Decision Making model is also developed to capture the complexity of human decision making related with risk attitude in the presence of ambiguity and uncertainty. Apart from rationality, the decision makers' biases, emotions and subjective feelings are also captured in this model.