In this reading selection, you will study in greater detail the steps and/or procedures that an engineer goes through in solving problems.  Essentially, we will look at the engineer's problem-solving process.

STEP ONE:

An engineer must be trained and be competent to plan and manage a project.   Suppose you were asked to plan a school picnic.  Here are the factors you need to consider (you may think of others as you plan and manage your project.) Who will participate?  When?  Where?  What type of transportation will the guests need to get there?  What kinds of food and drink will you serve?  How much food and drink will you need for each person? How many people will be involved? What games will the guests play?  Should there be an emergency kit? Who will be responsible for arranging food?  Drinks? Transportation? Games? How will you dispose of the garbage?   How much will each participant have to pay?  What is the procedure if someone does not show up at the meeting place?  What if someone forgets the food, drinks, or games he or she was supposed to bring?  What if it rains (for example, who is supposed to notify whom)? If the weather is doubtful, how will you decide whether or not to cancel?  And so on.

Though planning a picnic may seem simple enough, when you break down the steps and think how to get each one done, you can be on the way toward appreciating the challenges involved in solving such typical engineering problems as building a house, operating a factory, assembling an automobile, or launching a space shuttle.  Planning and managing an engineering project involves careful consideration of all aspects of the project from start to finish.

STEP TWO:

An engineer often builds a model for help in studying the problem or actually solving it.  Modeling helps to conceptualize the problem to be solved and the solution itself, expressing them as much as possible in quantitative terms.

Just as the artist (painter, photographer, sculptor, musician, or write) attempts to represent an experience by means of a composition, the engineer uses a model to represent the performance of a product or the execution of a task.  The engineer does not just blunder into creation, but rather uses imagination combined with a thoughtful, systematic approach to represent a product before building it.  He or she may use drawing, charts, graphs, or even pictures to help in solving the problem.  The goal is to develop a useful example of a real situation - an example that can be easily handled in repeated attempts to find the best solution.

STEP THREE:

Every engineer faces constraints that must be identified and taken into account in designing a solution to a problem.  Some constraints are natural, such as the conservation laws for mass, energy, and momentum as well as rate-related processes, such as diffusion, heat transfer (conduction, convection, and radiation), electrical conductivity, and friction.

In trying to understand what engineering is all about, you need to realize that the engineer must copy with limits in designing a product, just as there are limits to the range of your everyday actions.  Part of the challenge in understanding engineering is to learn how to find out where those limits are.

Some limitations are determined by the laws of nature itself.  Sometimes we have been able to overcome one natural constraint by utilizing another natural law.   In all situations, however, engineers need to have a thorough understanding of the natural processes related to the problems they wish to solve.  Other constraints stem from limits on the availability of energy, materials, tools, and human skills. Further constraints - and ones that are increasingly important as technology becomes so powerful and pervasive - are driven by economic, safety, biological, and health concerns as well as ethical, sociological, and political considerations.

STEP FOUR:

Engineers adhere to a philosophy called optimization in solving problems.   The philosophy of optimization states that one seeks to find the best possible solution given all the relevant restraints that must be considered.  In finding the best solution, engineers make trade-offs among the many factors that determine the final design and cost of a problem, such as construction costs, efficiency, operational costs (for example, the lifetime cost of owning and running a refrigerator), aesthetics, resource use, safety, and ethical concerns.

Engineering problems often lead themselves to more than one solution.  The challenge of the engineer is to find the best product - all things considered.  A completely safe car, for example, may be so expensive that no one could afford it.

STEP FIVE:

The design of the product is the heart of the engineering process.  The design created by the engineer represents the results of the processes described above.   It is the blueprint of an actual product or process.  The design may be tangible (for example, a bridge or a refinery) or intangible (for example, a set of instructions or a computer program).  It's a depiction of how the goal can be achieved.  The design is the engineer's creative plan for solving the problem.

It is critical, however, as engineers develop designs for solving the immediate problem before them, that they also consider such issues as maintenance and environmental protection.

STEP SIX:

Every design has side effects.  Examples of products and their side effects include an internal combustion engine that pollutes the air and creates noise, a heart pacemaker that puts its user at risk in a magnetic field, a computer that may strain the user's eyes and make the workplace more impersonal, a lead water pipe that may slowly poison the public, new roads that may aggravate rather than alleviate traffic congestion, an upholstered fabric that may pose a fire hazard, and a pesticide that may solve one problem but lead to others.

Consideration of side effects is - and will continue to be - of increasing importance and concern.  In fact, progress in technology has helped identify side effects that were not thought of when the design was created (for example, improvements in the sensitivity of measurement equipment have made it possible to detect minute concentrations of toxic materials). Examples of side effects abound.  Identifying the side effects of proposed technologies or technological solutions in time is an ever-increasing technical and societal challenge.

STEP SEVEN:

The products created by design cannot be allowed to perform unassisted; they require operating supervision, maintenance, and repair.  The performance of products must be monitored for the occurrence of unexpected events the design can't handle (for example, runaway chemical reactions, wind shear on an aircraft, and unexpected loads on a bridge).  Engineered systems need to be watched for signs of ordinary wear and tear as well.  No design is perfect, and no product is immune form "illness" or "mortality," any more than any living organism is.

STEP EIGHT:

We must be constantly alert to the possibility of engineering failure; most failures occur where systems meet each other.  No system is immune to failure, no matter how well-maintained and supervised.

Engineers need to appreciate the nature of the interactions between the human and technological components of a system (the socio-technology of the system). Famous examples include the space shuttle Challenger's failure, the Chernobyl nuclear power plant explosion, and the sinking of the Titanic (which all show a combination of design errors or weaknesses and of human error in operations).

Products may fail because of deficiencies or oversights in the design, because of conditions not expected by even the most careful designer, or because of improper use (human error).