Decision Science (also called Management Science or Operation Research) is an approach to decision making which utilizes extensively quantitative analysis. Students training to become managers, who work in or interact with, the service and or the manufacturing industries need to know how managers can solve both simple and complex problems using mathematical models. This text provides students with a sound conceptual understanding of the role Decision Science plays in the decision-making process. It focuses on the application of decision science by using problem situations to introduce each of the concepts and techniques used to evaluate practical problems and make decisions about issues they will face in their future careers. Decision Science has been designed to meet the needs of students with weak mathematical background who are studying business and economics.