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Engineering is the application of science to the needs of humanity. This is accomplished through knowledge, mathematics, and practical experience applied to the design of useful objects or processes. Professional practitioners of engineering are called engineers.


Compared to other professions

You see things; and you say "Why?" But I dream things that never were; and I say "Why not?"
George Bernard Shaw
An engineer is one who can do for two bob {two British shillings} what any fool can do for a quid {one British pound}

Engineering is concerned with the design of a solution to a practical problem. A scientist may ask "why?" and proceed to research the answer to the question. By contrast, engineers want to know how to solve a problem, and how to implement that solution.

In other words, scientists investigate phenomena, whereas engineers create solutions to problems or improve upon existing solutions. However, in the course of their work, scientists may have to complete engineering tasks (such as: designing experimental apparatus, or building prototypes), while engineers often have to do research.

However, engineering research has a different character to scientific research. Firstly, it often deals with areas where the basic physics and/or chemistry are well understood, but the problems are too complex to solve exactly. The purpose of engineering research is then to find approximations to the solution that can be solved. Examples are the use of numerical approximations to the Navier-Stokes equations to solve aerodynamic flow over an aircraft, or the use of Miner's rule to calculate fatigue damage to an engineering structure. Secondly, it employs many semi-empirical methods that are foreign to pure scientific research, for example the method of parameter variation.

In general, it can be stated that a scientist builds in order to learn, but an engineer learns in order to build.

As an illustrative example, on November 21, 1877, Thomas A. Edison developed the phonograph — a remarkable feat of engineering. Then, he directed his assistant (the technologist) to improve the device further by removing harmonics from the sound output.

The task of engineering

"An engineer is someone who can do for a dime what any fool can do for a dollar."

The crucial and unique task of the engineer is to identify, understand, and integrate the constraints on a design in order to produce a successful result. It is usually not enough to build a technically successful product; it must also meet further requirements. Constraints may include available resources, physical or technical limitations, flexibility for future modifications and additions, and other factors, such as requirements for cost, manufacturability, and serviceability. By understanding the constraints, engineers deduce specifications for the limits within which a viable object or system may be produced and operated.

Problem solving

Engineers use their knowledge of science and mathematics, and appropriate experience, to find suitable solutions to a problem. Creating an appropriate mathematical model of a problem allows them to analyze it (perhaps, but rarely, definitively), and to test potential solutions. Usually multiple reasonable solutions exist, so engineers must evaluate the different design choices on their merits and choose the solution that best meets their requirements. Compromises are at the heart of all engineering designs; the "best" design is that which meets as many of the requirements as possible.

Engineers typically attempt to predict how well their designs will perform to their specifications prior to full-scale production. They use, among other things: prototypes, scale models, simulations, destructive tests, nondestructive testing, and stress tests. Testing ensures that products will perform as expected. Engineers as professionals take seriously their responsibility to produce designs that will perform as expected and will not cause unintended harm to the public at large. Engineers typically include a factor of safety in their designs to reduce the risk of unexpected failure. However, the larger the safety factor, the less efficient the design will be.


In most modern countries, certain engineering tasks, such as the design of bridges, electric power plants, and chemical plants, must be approved by a Professional Engineer. Laws protecting public health and safety mandate that a professional must provide guidance gained through education and experience. In the United States, each state tests and licenses Professional Engineers.

The federal government, however, supervises aviation through the Federal Aviation Regulations administrated by the Dept. of Transportation, Federal Aviation Administration. Designated Engineering Representatives approve data for aircraft design and repairs on behalf of the Federal Aviation Administration.

Even with strict testing and licensure, engineering disasters still occur. Therefore, the Professional Engineer adheres to a strict code of ethics. Each engineering discipline and professional society maintain a code of ethics, which the members pledge to uphold.

Use of computers

As with all modern scientific and technological endeavours, computers and software play an increasingly important role. Numerical methods and simulations can help predict design performance more accurately than previous approximations.

Using computer-aided design (CAD) software, engineers are able to more easily create drawings and models of their designs. Computer models of designs can be checked for flaws without having to make expensive and time-consuming prototypes. The computer can automatically translate some models to instructions suitable for automatic machinery (e.g., CNC) to fabricate (part of) a design. The computer also allows increased reuse of previously developed designs, by presenting an engineer with a library of predefined parts ready to be used in designs.

Of late, the use of finite element method analysis (FEM analysis or FEA) software to study stress, temperature, flow as well as electromagnetic fields has gained importance. In addition, a variety of software is available to analyse dynamic systems.

Electronics engineers make use of a variety of circuit schematics software to aid in the creation of circuit designs that perform an electronic task when used for a printed circuit board (PCB) or a computer chip.

Sooner or later, the electronic computers would be outdated. Engineers can nowadays solve engineering problems using their mobile phones such as designing a beam at the construction site without the aid of a desktop or laptop ( Source: Horng Hean TEE, September 2004, “Mobile Structural Software / WAP Structural Engineering Applications”, Suara Perunding, Association of Consulting Engineers Malaysia, Kuala Lumpur and Horng Hean TEE, 1 February 2005, “Developing WAP Structural Applications”, The Structural Engineer, The Institution of Structural Engineers, London)


It is a myth that engineer originated to describe those who built engines. In fact, the words engine and engineer (as well as ingenious) developed in parallel from the Latin root ingeniosus, meaning "skilled". An engineer is thus a clever, practical, problem solver. The spelling of engineer was later influenced by back-formation from engine. The term later evolved to include all fields where the skills of application of the scientific method are used. In some other languages, such as Arabic, the word for "engineering" also means "geometry".

The fields that became what we now call engineering were known as the mechanic arts in the 19th century.

Connections to other disciplines

Science attempts to explain newly observed and unexplained phenomena, often creating mathematical models of observed phenomena. Technology and engineering are attempts at practical application of knowledge (often from science). Scientists work on science; engineers work on technology. However, there is often an overlap between science and engineering. It is not uncommon for scientists to become involved in the practical application of their discoveries; thereby becoming, for the moment, engineers. Conversely, in the process of developing technology engineers sometimes find themselves exploring new phenomena, thus becoming, for the moment, scientists.

There are significant parallels between the practice of medicine and engineering. Both professions are well known for their pragmatism — the solution to real world problems often requires moving forward before phenomena are completely understood in a more rigorous scientific sense.

There are also close connections between the workings of engineers and artists; they are direct in some fields, for example, architecture / landscape architecture and industrial design, and indirect in others. Artistic and engineering creativity may be fundamentally connected.

Engineers in culture

Historically, engineering has been seen as a somewhat dry, uninteresting field in popular culture, and has also been thought to be the domain of nerds (with little of the romance that attaches to hacker culture). For example, the cartoon character Dilbert is an engineer.

In science-fiction engineers are often portrayed as highly knowledgeable and respectable individuals who understand the overwhelming future technologies often portrayed in the genre. The Star Trek characters Montgomery Scott and Geordi LaForge are famous examples.

Engineers are often respected and ridiculed for their intense beliefs and interests. Perhaps because of their deep understanding of the interconnectedness of many things, engineers such as Governor John H. Sununu are often driven into politics to "fix things" for the public good.

Occasionally, engineers may be recognized by a stainless steel ring, worn on the fifth finger of the working hand. This tradition was developed in Canada at the University of Toronto and was originally an iron ring. Some years later this practice was adopted by the United States. Members of the US Order of the Engineer accept this ring as a pledge to uphold the proud history of engineering. A Professional Engineer's name often has the post-nominal letters PE or P.Eng.

See also


  • Petroski, Henry, To Engineer is Human: The Role of Failure in Successful Design, Vintage, 1992
  • Petroski, Henry, The Evolution of Useful Things: How Everyday Artifacts-From Forks and Pins to Paper Clips and Zippers-Came to be as They are, Vintage, 1994
  • Vincenti, Walter G. What Engineers Know and How They Know It: Analytical Studies from Aeronautical History, Johns Hopkins University Press, 1993



Major branches (Top 14)

See fields of engineering for a full listing.


External links

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