One trick they used on the professional engineer's exam was to ask vague, open-ended questions.
The answer was highly subjective.
The approach to take was to state every assumption you made, and then work the problem based on your assumptions.
I did well with these types of questions, but was a bit shocked when I saw the first one.
When designing things in the real world, there is never one answer or one solution to anything.
For students who go through school with every question being multiple choice, they struggle when given infinite choices.
I generally ask a client the following, before proceeding with a solution to a problem:
1. How much money do you want to spend?
2. How long do you need it to last?
3. How easy of access to it do you need for maintenance?
4. Are there any limitations on the amount of space I can use?
5. Do you have a favorite vendor that you prefer?
6. Do you have adequate power available to feed the equipment? If not, do we need to expand the power source?
Then I start the layout, and start making calculations.
Some clients have basically infinite money (such as a large air freight company in town), and they want the very best money can buy ,and something that will last forever and never break.
Diddo for the local refinery, and large wastewater plants.
Other clients may be tight on money, and so they trade off things.
For big clients, who can't afford a shutdown for any reason, the cheapest overall long term design often has the highest initial expense.
As I have told some young students, don't crack walnuts with a locomotive.
But if you do have a big problem, don't hesitate to use a locomotive.
One student asked "How do I know when to use a locomotive, and when not to use a locomotive".
My response was "That is the art of engineering. There are often no simplistic solutions in the real world, and you have to learn when to use what."
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