Engineering economics

Engineering economics, previously known as engineering economy, is a subset of economics concerned with the use and "...application of economic principles" in the analysis of engineering decisions. As a discipline, it is focused on the branch of economics known as microeconomics in that it studies the behavior of individuals and firms in making decisions regarding the allocation of limited resources. Thus, it focuses on the decision making process, its context and environment. It is pragmatic by nature, integrating economic theory with engineering practice. But, it is also a simplified application of micro-economic theory in that it avoids a number of micro-economic concepts such as price determination, competition and demand/supply. As a discipline though, it is closely related to others such as Statistics, Mathematics and Cost Accounting. It draws upon the logical framework of economics but adds to that the analytical power of mathematics and statistics.
Engineers seek solutions to problems, and the economic viability of each potential solution is normally considered along with the technical aspects. Fundamentally, engineering economics involves formulating, estimating, and evaluating the economic outcomes when alternatives to accomplish a defined purpose are available.

In some U.S. undergraduate Civil engineering curricula, engineering economics is a required course. It is a topic on the Fundamentals of Engineering examination, and questions might also be asked on the Principles and Practice of Engineering examination; both are part of the Professional Engineering registration process.

Considering the time value of money is central to most engineering economic analyses. Cash flows are discounted using an interest rate, i, except in the most basic economic studies.

For each problem, there are usually many possible alternatives. One option that must be considered in each analysis, and is often the choice, is the do nothing alternative. The opportunity cost of making one choice over another must also be considered. There are also non-economic factors to be considered, like color, style, public image, etc.; such factors are termed attributes.

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