Welcome to ENGR 1201 !!!
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“If you, as with all humans since the birth of man, desire change; if the system you want to change is complex and poorly understood, if the change you will accept must be the best available, and if it is constrained by limited resources, then you are in the presence of an engineering problem. If you cause this change … then you are an engineer." - Koen
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Read Heuristics and The Engineering Method - taken from Koen's work which can be read here: link
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What is an engineer?
The word engineer is derived from the Latin:
- ingeniare "to contrive, devise"
- ingenium "cleverness"
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What is the difference between:
- a scientist,
- a technician,
- and an engineer?
A mathematician, a scientist, and an engineer walk into a bar....
On the way back to work, they pass an open office and observe that there is a fire starting in the corner of the room.
The mathematician looks around, observes that there is a fire extinguisher on the wall and walks on. He is satisfied that the problem has a solution.
The scientist grabs his pocket calculator, estimates the size of the room, the amount of combustible material, etc, checks the tag on the fire extinguisher to see what size fire it can handle, and after some calculation, he too walks on. He has confirmed that the problem's solution is at hand.
The engineer grabs the fire extinguisher and puts out the fire while the other two are fooling around.
This is the difference between a mathematician, a scientist, and an engineer....
Engineering is applied.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~What does "applied" mean?
applied =
crossing over from "theory"
to "reality"...~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Scientist
A scientist is an individual who uses the scientific method.
The “Scientific” method:
- - Formulate a question,
- - make a hypothesis or theory,
- - predict what would happen if the theory or hypothesis is true,
- - test the hypothesis through experimentation, observations, empirical measurements
- - analyze experimental results,
- - make conclusions based on results).
The “Engineering” method
“The use of engineering heuristics to cause the best change in a poorly understood situation within the available resources.” - Koen
- Define a problem – identify a situation that needs to be changed.
- Access available resources, needs/wants of society
- Propose and critique possible solutions using a combination of analytic analysis, and heuristic speculations about societal needs, and personal ethics.
- Build a product
- Test, evaluate, refine, and rebuild product considering the evolving needs of society.
The Design Process presented in your text has 10 phases:
PGR.BAT.DCCR.
1. Identify the Problem/product innovation
2. Define the working criteria/Goals
3. Research and gather data
4. Brainstorm/generate creative ideas
5. Analyze potential solutions
6. Develop and Test models
7. Make the Decision
8. Communicate and specify
9. Implement and Commercialize
10. Perform post-implementation Review and assessment
From: The “Engineering” Method (Billy Vaughn Koen – American Society for Engineering Education)
4 key components an Engineer must balance:
- need for change,
- limited resources,
- determining what’s best,
- dealing with uncertainty.
1. Change
Engineers cause change – they are creationists.
build a dam, and change the landscape,
build a road, invite a housing development,
the before/after picture is different after an engineer has been on the scene.
“To identify a situation calling for an engineer, is to identify a situation calling for change.”
You start at point A, not knowing quite what point B will look like or how they are going to get there… You deal with open-ended problems.
example: The Aswan High Dam in Egypt
11,811 feet long,
3,215 feet thick at the base
364 feet tall
– consider before / after… state A – state B.
a.) increased the salinity of the Nile by 10%
b.) led to the collapse of the sardine industry in the Delta
c.) caused coastal erosion
d.) displaced 100,000 Nubians from their home, forced them to adapt to life as farmers on newly created land.
e.) generation of enough hydroelectric power to furnish half of Egypt’s electrical needs.
The engineer is willing to develop a transition strategy, but rarely is given a specific, well-defined problem to solve. Instead, he must determine for himself what the actual problem is on the basis of society’s diffuse desire for change.
The destination:
Often "B" changes through the design process
- It takes 5-12 years to build a nuclear reactor during which time presidents change, society changes, etc.
- Automotive industry - First society wants power, then they want safe, then they want small and efficient - "B" shifts around quickly.
The Path:
The creative process is very seldom a straight line. Most roads you drive on curve and twist, because it’s faster and more practical to go around things like the Grand Canyon than to go “straight” through them.
Walking straight into circles
by Jan L. Souman
, Ilja Frissen, Manish N. Sreenivasa, Marc O. Ernst
Current Biology, Volume 19, Issue 18, 1538-1542, 20 August 2009
Abstract: "Common belief has it that people who get lost in unfamiliar terrain often end up walking in circles. Although uncorroborated by empirical data, this belief has widely permeated popular culture. Here, we tested the ability of humans to walk on a straight course through unfamiliar terrain in two different environments: a large forest area and the Sahara desert. Walking trajectories of several hours were captured via global positioning system, showing that participants repeatedly walked in circles when they could not see the sun. Conversely, when the sun was visible, participants sometimes veered from a straight course but did not walk in circles. We tested various explanations for this walking behavior by assessing the ability of people to maintain a fixed course while blindfolded. Under these conditions, participants walked in often surprisingly small circles (diameter < 20 m), though rarely in a systematic direction."
Moral of the story -
Engineers (and everyone) need clearly defined goals and reference points. It's best to try and clearly define "B" from the start (as hard as that might be) and stick to it. Every project is a failure in the middle, nothing is perfect, but if you stick with your goal, you'll eventually accomplish something.
What is the difference between a technician and an engineer?
A technician implements a defined change.
An engineer has to decide which of the many paths from A to B they should take, and what B is.
2. Limited Resources
Solutions must be consistent with the available time, physical, economic, & political resources. Resources both define, and constrain solutions.
Example Problem #1: In 50 seconds, estimate the number of ping-pong balls that can fit in this classroom.
(importance of resources – you only have 50 seconds, you don’t have a tape measure, you don’t have enough ping-pong balls to actually fill the classroom, and then count them) ping pong balls are 1.38” in diameter, V = 4/3 pi r^3 = 1.4in^3. 0.74 highest packing density for spheres,...
Example Problem #2: What is the temperature of this room?
No exact solution - temperature changes with time and space, it's different by the door than by the window, etc.
Unlike science and math, there are no exact answers in engineering.
3. Best
Instead of looking for “the” answer to a problem (as does the scientist), the engineer seeks “the most optimal” answer to a problem considering the resources available to them.
Not all final states are equally desirable – not all paths are the same, and “best” is a subjective adjective.
Example: – try to define “best” vehicle design -
Is a Dodge better than a Mustang or a Mercedes? It’s subjective and relative to the application.
To exist, means it was some engineer’s notion of “best”.
Unlike science, engineering does not seek to model reality, but society’s perception of reality, including its myths and prejudices.
Beer vending machine...
"In a society of cannibals, the engineer will try to design the most efficient kettle."
“best” in science = closest to approximating reality.
“best” in engineering = balance of “wants” to resources/$
Engineers often manipulate society’s perceived wants – engineers create what they think an informed society should want based on their knowledge of what an uninformed society thinks it wants.
4. Uncertainty
Example: San Francisco’s Embarcadero “freeway to nowhere”
– engineers designed for the “best” way to move traffic…
highway was abandoned mid-construction because it failed to take into account...
“don’t block my view of the bay”,
“Don’t raise the noise level or density of people or increase pollution in my neighborhood”,
The difference between theory and practice –
“In theory, theory and practice are the same.
In practice, they are not.”― Albert Einstein
- theoretically a design will work wonderfully, but in practice there is always the possibility of having overlooked some criteria it needed to fulfill.
The doubt about the criteria that are important to society, doubt about the relative importance of these criteria (is it more important that a car is cheap? Or that is lasts a long time?).
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The principle Rule of the Engineering Method: Heuristics.
Chess is a complicated game that defies analytic analysis. There are no computers which are large enough to calculate the combinations and permutations of all possible games. To learn how to play chess, you don’t memorize all possible games – instead you go on suggestions, hints, and rules of thumb.
Chess Heuristics:
- Open with a center pawn
- Move a piece only once in the opening
- Develop the pieces quickly
- Castle on the King’s side as soon as possible
- Develop the queen late
- Control the center
- Establish outposts for the knights
- Keep bishops on open diagonals
- Increase your mobility
- hints and rules of thumb do not guarantee you will win, often offer conflicting advice, depend on context, and change with time – but “hints and rule of thumb” is the best that we have.
Artificial intelligence problem solving programming technique:
Instead of using an algorithm containing fixed deterministic steps (move forward 3 feet.stop.turn to the left.move 2 feet. Stop. Extend arm.open hand.take cookie.) The program uses heuristics.
Heuristics – list of random suggestions, hints, or rules of thumb to use in seeking a solution to a problem. Vague, non-analytic techniques work and are used in codes that play checkers, identify hurricane cloud formation, and control nuclear reactors.
Like chess, an engineer starts a project not knowing how the “game” will play out, with an infinite number of possible moves, paths, and outcomes that could be produced, and no way to analytically solve which solution should be taken. In the absence of an analytic solution – the use of Heuristics is an engineering strategy.
Objectives:
1 Understand the technical term “heuristic
2 develop the engineer’s strategy for change
3 define “state of the art”
4 state the principle rule for implementing the engineering method.
Heuristic
– “anything that provides a plausible aid or direction in the solution of a problem, but is unjustified, non-provable, and fallible. It is used as a rough guide to discover and to reveal. It is to use a rule of thumb, technique, hint, rule of craft, engineering judgment, working basis, or, if in France, “le pif” (the nose), to describe plausible (if fallible) basis of the engineer’s strategy for solving problems. Each of these terms captures the feeling of doubt characteristic of the heuristic."
1.A heuristic does not guarantee a solution
2.It may contradict other heuristics
3.It reduces the search time in solving a problem
4.Its acceptance depends on the immediate context instead of on an absolute standard.
Compare: scientific law vs. Engineering heuristic.
Inside of square U – set of all problems that can be solved. (theoretically solvable given perfect knowledge and infinite time) – will the sun rise, does bread nourish, how fast will this pen drop, should the Aswan high dam have been built?
Outside the box – anything else. Questions that cannot be answered, cannot be asked, pseudo questions. (Many scientists believe that no points, such as e and f, exist).
Note:
Engineers can think "outside the box"
BUT they also understand what is inside the box.
A,B,B’,C,D,I – sets of problems that can be solved using a specific scientific or mathematical theory, principle, or law. (set A with problem a = all problems solvable using conservation laws, B problems requiring physics etc.)
E, F,G, H – set of problems which use heuristics, lie inside and outside of box.
Scientist – considers ambiguity a fatal weakness.
Uncertainty about a solution’s validity indicates a heuristic (rather than law) has been used.
2.It may contradict other heuristics
Unlike scientific theories:
Two heuristics may contradict or give different answers to the same question, and still be valid. (For a mathematician, contradiction is worse than ambiguity).
What’s the best vehicle for a family?
Heuristic A.) large, safe van.
Heuristic B) small fuel-efficient $ saving vehicle
A and B contradict one another, but they are both useful…
3.It reduces the search time in solving a problem
Some problems are so serious and the analytical techniques so time-consuming (or nonexistent) that heuristic solution is better than no solution at all.
Example: New virus is lethal to the human species on a time scale shorter than the scientific theory can be developed to solve it, the only rational course is to use the irrational heuristic method.
"Better first aid in the field than a patient dead on arrival…" the solution on the field does not involve state of the art equipment, or trained doctors – isn’t the “absolute correct analytic solution” to the problem. Engineers do the best they can, with the resources they have, and in the timeframe the product is needed by. Engineering is not an “exact science”. Unfortunately, most of the problems facing mankind cannot be solved with “exact science”. – war, energy, hunger, pollution – like chess, the problems are so complex and poorly understood that analytical techniques inadequate. Heuristics quickly produce “good enough” solutions to analytically unsolvable problems.
"Well, let's see now... let's think this over...
an engineer never says “I don’t know”.
Neither do they claim to provide some holy grail analytic “correct” solution either – you estimate, guess, use heuristics, rules of thumb, general trends, and start progressing down a path step by step into the darkness. You don’t know exactly what lies ahead, your footing isn’t completely sure, nevertheless, you “Just keep swimming”.
4. Acceptance of a heuristic depends on the immediate context instead of on an absolute standard.
The validity of a heuristic – does it work, or is it useful in a specific relativistic context? It isn’t “right” or “wrong”, it’s only an idea that’s applicable in certain scenarios. Like the recipe for a cake – is there some absolute fact or truth about what recipe is correct? No, there are many ideas out there, and different occasions use different heuristics in the kitchen.
One heuristic does not replace another by confrontation but by doing a better job in a given context.
“Criticize by creation, not by finding fault.” – “Criticize by re-design.”
(The validity of science – is it true and consistent with assumed absolute reality?
New scientific theories replace old ones, one theory is considered “wrong” and another “right”. Eternal unchanging absolute “facts” are assumed to exist, and describing these facts are debated and argued over. “prove it!” etc. Old “laws” are replaced by new ones after confrontations and tearing apart credentials and egos.)
For engineers, the dependency on immediate context instead of absolute truth is the standard of validity and the final hallmark of a heuristic.
Criticism:
While debating what group project to do, keep in mind...
Usually, people aren't against you, they are for themselves.
When you blame and criticize others, often you are avoiding admitting some fault within yourself.
Before you talk, listen.
Act, don't react.
Question instead of argue.
Suggest something better, instead of criticize.
Never give up, never surrender.
"Our destiny is not determined by the number of times we stumble but by the number of times we rise up, dust ourselves off, and move forward."
State of the Art
Set of heuristics used by an engineer to solve a specific problem at a specific time. State of the Art devices are designed to best meet the current needs of the population (life expectancy changes, health needs change, what’s popular changes, and the heuristics – rules of thumb used to address new situations and challenges change. )
How to teach heuristics:
Apprentice system – rules of thumb taught to apprentice in the balck-smith shop, or farmer working with their dad growing up etc. etc.
“The impetuous George Washington was surveying frontier lands by the age of sixteen. By 21, with only a few months of formal education, he could ford rivers, chart mountains, charm legislators, and lead troops. Lord Fairfax wrote his mother that he was, “a man who will go to school all his life.” Washington’s classrooms were the forest, the battlefield, and the halls of government. He never asked what was going to be in the final.”
Education system has evolved from apprenticeships to books and professors. As an engineer, you have to realize that everything does not come out of a book – you need to be unusually sensitive to the physical world around you, and use what you intuitively know as part of your design. Be willing to accept new designs that you are unfamiliar with though. Realize your point of view, see others points of view.
In summary... Engineering has no hint of
- the absolute,
- the deterministic,
- the guaranteed,
- the true.
Instead, engineering fairly reeks of
- the uncertain,
- the provisional
- the doubtful.
The engineer instinctively recognizes this and calls his ad hoc method:
- “doing the best you can with what you've got”,
- “find a seat of the pants solution”
- or just “muddling through”
But... Engineers are able to see beyond the words and symbols in books to the physical realities that they represent.
Engineers are not afraid of an imperfect reality.
Their work makes them one of the principles sources humanity turns to for help, and progress.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Quotes about the differences between scientists and engineers:
Scientists are concerned about the fundamentals of things, whereas engineers are concerned about the application of fundamental knowledge.
"A scientist can discover a new star, but he cannot make one. He would have to ask an engineer to do that." — Gordon L. Glegg, British Engineer, 1969.
A "mad scientist" is an engineer
but a "mad engineer" is not a scientist.
"All engineers are scientists,
but all scientists are not engineers"
“Scientists study the world as it is;
engineers create the world that has never been.”
Engineers think that equations approximate the real world.
Scientists think that the real world approximates equations.
Mathematicians are unable to make the connection. Scientists apply laws to understand nature
engineers apply laws to create products and technology.
Engineers are practical,
Scientists are theoretical …
The work of engineers forms the link between scientific discoveries and their subsequent applications to human needs."
There is a need for understanding how to prevent coffee from spilling out of a cup while one carrying the cup is walking....
The
scientist pores over weeks of papers on fluid dynamics and human
biomechanics, homonid gait evolution and spends millions of dollars he
begged for in grant money....
The Engineer spends 2 cents and says "can I have a lid for this cup?"
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