This document provides definitions and overviews of engineering, economics, and engineering economics. It defines engineering as applying scientific knowledge to design and build structures, machines, and processes. Economics is defined as analyzing production, distribution, and consumption of goods and services. Engineering economics applies economic techniques to evaluate engineering design alternatives. It is used to determine which engineering projects are worthwhile and should have priority by justifying projects from an engineering standpoint. The document outlines classification of engineering economic problems and the nine elements of the decision making process in engineering economics.