Introduction: How to Solve Engineering Problems
These Instructables have been created in order to help young, aspiring engineers develop a critical skill set that will help them through their schooling and throughout their careers. This skill set will become a repetitive process that can be applied over and over again to any problem that they may encounter at any time. These instructions are not limited to only engineers however, as many professionals or other students can find these useful for solving problems in their respective fields. For the purpose of this Instructable, I will walk you through the generic steps that should be taken in this process and then I will solve an engineering related problem using these steps.
The picture below shows how complex a design can be, but using the following method can take something this complex and break it into simpler parts while keeping it a beautiful design. Thanks to http://farm3.static.flickr.com/2383/2518751632_53119dfd58.jpg for providing the picture!
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Step 1: Materials Needed
For a majority of these problems, only a few things are needed to help you solve them. They are a calculator, scale, paper, and pencil. This may sound like very little supplies but it really is all that one needs. I would recommend a scientific calculator for these problems since they will most likely contain equations that are too difficult to be handled by a simple calculator. Any kind of paper will work but grid paper is generally the most useful so you can keep things organized vertically and horizontally. If you do not have a scale, a plain ruler will suffice. The scale/ruler will help you keep your schematic drawings neat and easy for both you and your professor/boss to follow.
Step 2: Problem Statement
Once you have collected everything that you need to solve the problem, you need to read through it. This is a vital step in the overall process. Numerous young engineers have a tendency to simply scan the problem, but this poses a problem since they end up missing information that would likely make the problem simpler. The best thing to do for this step is read the problem thoroughly and to read it twice, making sure that you have gathered all the information.
Step 3: Given/Find
After reading through the problem two or three times, it is important for you to extract all the necessary information. List out what you have or what is given to you. This can be constraints, variables, values, or even equations that link some of the variables together. It is important for you to list all these things so that you will not have to continuously scan the problem over and over looking for certain values.
After you list your given information, make sure you understand what is being asked. For most problems (like the one I am working through), it is directly asked to you to find something. Make sure you write this down as you are working to ensure you do not solve something you do not need.
Step 4: Assumptions
Once you have completed the previous steps, you need to make a list of acceptable assumptions for your problem. It is important to remember to work easier not harder! Assumptions allow you to make your complex problem a simpler model which will give results that are just as valid. However, it is also important that you do not make assumptions that will make your results unacceptable. This is the most difficult step of the skill set to grow accustomed to. It takes time, practice, and patience to understand what assumptions become acceptable and what ones do not!
Step 5: Schematic Drawings
Once you have read through the problem, defined what was given and what needs to be found, and listed your assumptions, you need to create a schematic. The schematic drawing or drawings allow you to physically see what is happening in the problem. This can help you as you begin to go through your equations and analysis, as well as helping you verify your answers once you get them. You will be able to go back and check your values to ensure that everything.
Step 6: Equations/Analysis
This step is the one that most young engineers immediately jump into when trying to solve problems. However, as you have seen, this should be one of the last steps that are taken. For this step, first write out the equations that you will be using. There is no need to solve them just yet, write out the equations in their variable form. This will allow you to make sure you have all the information you need to solve that equation. If you do not, you will need to find another equation or equations that solve for the unknown variable/variables.
The second part of this step is to actually solve your equations, whether it is one equation or five equations simultaneously. In some instances, your question may ask for multiple variables or it may just ask for one variable. This is where all of your work finally begins to make sense and you can see how your problem is finishing up. Solving should be one of the easier steps, all you should have to do is plug the values into your calculator and get the results.
Step 7: Results
Here is the step that everyone just wants to get to! You finally get to see your results for all of the work that you have put in. It is important to make sure that your results are easy to see, so a lot of people prefer either a double underline under the result or a box around it. This makes it easy to find and leaves no question as to what your answer might or might not be.
Step 8: Verification
After you have completed all steps up to this point, you only have one left! Verifying your answer is a big step for a couple of different reasons. One reason that it is so important to verify your results is to make sure that your answer makes sense. For example, if a flow should be in the positive x-direction, a negative answer would imply that the flow is going opposite of what it should. It is also important to verify your results to make sure that your answer has proper units. It would not be a legitimate answer if you had units for velocity (m/s) for a problem where you were trying to solve for a force (N). The last reason it is important to verify your results is that it is a good habit to get into before you enter the workplace. Here, you will need to make sure your answers are right and that they make sense since you can be held accountable for your work.