You are here:Home /e-Engineer
E-Engineer
| |

Institution

|

Industry

|

Community Development

PROSPERITY CONSULTING GROUP

Architect – Engineer - Planner

18501 Vidora Dr. #A Rowland Hts, Ca 91748

www.e-Architect.us

www.e-Engineer.us

www.e-Planner.us

PROSPERITY CONSULTING GROUP

Architect – Engineer - Planner

18501 Vidora Dr. #A Rowland Hts, Ca 91748

www.e-Architect.us

www.e-Engineer.us

www.e-Planner.us

Prosperity Consulting Group 2005, All rights Reserved Prosperity Consulting Group 2005.

Transportation Engineering (*)
Timber Design (*)
Design Procedures (*)
Engineering Drafting & Design ( I & II ) (*)
Construction Process and Cost Estimating (*)
Traffic Planning & Economics (*)
Surveying (*)
*Courses Taught by George K. Chou at Northrop University
National Society of Professional Engineers Engineers
Civil Engineer American Society of Civil Engineers
Engineers International Institute of Transportation Engineers
Federal Emergency Management Agency American National Standards Institute
US Army Corps of Engineers Home Page ASTM INTERNATIONAL

Structural Engineers Association International

The American Society of Plumbing Engineers

National Council of Structural Engineers Association

Engineering News Record

U.S. Department of Labor-Engineers

College Board
Institute of Electrical and Electronics Engineers Power Plant Scientists
American Institute of Chemical Engineers Online Chemical Engineering Information

Building News

the Internet Guide to engineering, Mathematics and Computing

Future City Competition

McGraw-Hill's Best Basic Engineering Series and Tools
ENGINEERING ECONOMICS
WHY DO ENGINEERS NEED TO LEARN ABOUT ECONOMICS?
Ages ago, the most significant barriers to engineers were technological. The things that engineers wanted to do, they simply did not yet know how to do, or hadn't yet developed the tools to do. There are certainly many more challenges like this which face present-day engineers. However, we have reached the point in engineering where it is no longer possible, in most cases, simply to design and build things for the sake simply of designing and building them. Natural resources (from which we must build things) are becoming more scarce and more expensive. We are much more aware of negative side-effects of engineering innovations (such as air pollution from automobiles) than ever before.
For these reasons, engineers are tasked more and more to place their project ideas within the larger framework of the environment within a specific planet, country, or region. Engineers must ask themselves if a particular project will offer some net benefit to the people who will be affected by the project, after considering its inherent benefits, plus any negative side-effects (externalities), plus the cost of consuming natural resources, both in the price that must be paid for them and the realization that once they are used for that project, they will no longer be available for any other project(s).
Simply put, engineers must decide if the benefits of a project exceed its costs, and must make this comparison in a unified framework. The framework within which to make this comparison is the field of engineering economics, which strives to answer exactly these questions, and perhaps more. The Accreditation Board for Engineering and Technology (ABET) states that engineering "is the profession in which a knowledge of the mathematical and natural sciences gained by study, experience, and practice is applied with judgment to develop ways to utilize, economically, the materials and forces of nature for the benefit of mankind".1
Physical and Economic Components of an Engineering System
  1. Physical Environment : Engineers produce products and services depending on physical laws (e.g. Ohm's law; Newton's law).

Physical efficiency takes the form:                                 

    System output(s)
Physical (efficiency )
= -------------------------
    System input(s)
  1. Economic Environment : Much less of a quantitative nature is known about economic environments -- this is due to economics being involved with the actions of people, and the structure of organizations.

Satisfaction of the physical and economic environments is linked through production and construction processes. Engineers need to manipulate systems to achieve a balance in attributes in both the physical and economic environments, and within the bounds of limited resources. Following are some examples where engineering economy plays a crucial role:

    1. Choosing the best design for a high-efficiency gas furnace
    2. Selecting the most suitable robot for a welding operation on an automotive assembly line
    3. Making a recommendation about whether jet airplanes for an overnight delivery service should be purchased or leased
    4. Considering the choice between reusable and disposable bottles for high-demand beverages

With items 1 and 2 in particular, note that coursework in engineering should provide sufficient means to determine a good design for a furnace, or a suitable robot for an assembly line, but it is the economic evaluation that allows the further definition of a best design or the most suitable robot.
In item 1 of the list above, what is meant by " high-efficiency"? There are two kinds of efficiency that engineers must be concerned with. The first is physical efficiency, which takes the form:

    System output(s)
Economic (efficiency )
= -------------------------
    System input(s)
For the furnace, the system outputs might be measured in units of heat energy, and the inputs in units of electrical energy, and if these units are consistent, then physical efficiency is measured as a ratio between zero and one. Certain laws of physics (e.g., conservation of energy) dictate that the output from a system can never exceed the input to a system, if these are measured in consistent units. All a particular system can do is change from one form of energy (e.g. electrical) to another (e.g., heat). There are losses incurred along the way, due to electrical resistance, friction, etc., which always yield efficiencies less than one. In an automobile, for example, 10-15% of the energy supplied by the fuel might be consumed simply overcoming the internal friction of the engine. A perfectly efficient system would be the theoretically impossible Perpetual Motion Machine!
You might have heard economic efficiency referred to as "benefit-cost ratio". Both terms of this ratio are assumed to be of monetary units, such as dollars. In contrast to physical efficiency, economic efficiency can exceed unity, and in fact should, if a project is to be deemed economically feasible. The most difficult part of determining economic efficiency is accounting for all the factors which might be considered benefits or costs of a particular project, and converting these benefits or costs into a monetary equivalent. Consider for example a transportation construction project which promises to reduce everyone's travel time to work. How do we place a value on that travel time savings? This is one of the fundamental questions of engineering economics.
In the final evaluation of most ventures, economic efficiency takes precedence over physical efficiency because projects cannot be approved, regardless of their physical efficiency, if there is no conceived demand for them amongst the public, if they are economically infeasible, or if they do not constitute the "wisest" use of those resources which they require.
There are numerous examples of engineering systems that have physical design but little economic worth (i.e it may simply be too expensive !!). Consider a proposal to purify all of the water used by a large city by boiling it and collecting it again through condensation. This type of experiment is done in junior physical science labs every day, but at the scale required by a large city, is simply too costly.
ROLE OF UNCERTAINTY IN ENGINEERING
When conducting engineering economic analyses, it will be assumed at first, for simplicity, that benefits, costs, and physical quantities will be known with a high degree of confidence. This degree of confidence is sometimes called assumed certainty. In virtually all situations, however, there is some doubt as to the ultimate values of various quantities. Both risk and uncertainty in decision-making activities are caused by a lack of precise knowledge regarding future conditions, technological developments, synergies among funded projects, etc. Decisions under risk are decisions in which the analyst models the decision problem in terms of assumed possible future outcomes, or scenarios, whose probabilities of occurrence can be estimated. Of course, this type of analysis requires an understanding of the field of probability. Decisions under uncertainty, by contrast, are decision problems characterized by several unknown futures for which probabilities of occurrence cannot be estimated. Other less objective means exist for the analysis of such problems.
For the purposes of this brief tutorial, we cannot delve further into the analytical extensions required to accommodate risk or uncertainty in the decision process. We must recognize that these things exist, however, and be careful about reaching strong conclusions based on data which might be susceptible to these. Because engineering is concerned with actions to be taken in the future, an important part of the engineering process is improving the certainty of decisions with respect to satisfying the objectives of engineering applications.
THE ENGINEERING PROCESS
Engineering activities dealing with elements of the physical environment take place to meet human needs that arise in an economic setting. The engineering process employed from the time a particular need is recognized until it is satisfied may be divided into a number of phases:

Engineering activities dealing with elements of the physical environment take place to meet human needs that arise in an economic setting. The engineering process employed from the time a particular need is recognized until it is satisfied may be divided into a number of phases:

  1. Determination of Objectives

This step involves finding out what people need and want that can be supplied by engineering. People's wants may arise from logical considerations, emotional drives, or a combination of the two.

  1. Identification of Strategic Factors

The factors that stand in the way of attaining objectives are known as limiting factors. Once the limiting factors have been identified, they are examined to locate strategic factors -- those factors which can be altered to remove limitations restricting the success of an undertaking. A woman who wants to empty the water from her swimming pool might be faced with the limiting factor that she only has a bucket to do the job with, and this would require far greater time and physical exertion than she has at her disposal. A strategic factor developed in response to this limitation would be the procurement of some sort of pumping device which could do the job much more quickly, with almost no physical effort on the part of the woman.

  1. Determination of means (engineering proposals)

This step involves discovering what means exist to alter strategic factors in order to overcome limiting factors. In the previous example, one means was to buy (or rent) a pump. Of course, if the woman had a garden hose, she might have been able to siphon the water out of the pump. In other engineering applications, it may be necessary to fabricate the means to solve problems from scratch.

  1. Evaluation of Engineering Proposals

It is usually possible to accomplish the same result with a variety of means. Once these means have been described fully, in the form of project proposals, economic analysis can be employed to determine which among them, if any, is the best means for solving the problem at hand.

  1. Assistance in Decision Making
page:1 2