Completing a mechanical engineering degree and then getting a job is eye opening for everyone. One of the things that surprised me was how little I used all the things I learned in school. This is very job specific, but I have heard it from a variety of engineers (and people with other degrees as well). It can feel like a four year degree’s only purpose is to get you through the hiring manager’s door – after that it doesn’t carry a lot of weight. What you do on a day to day basis is based on what you learned on the job. I used to think this myself.
Then the boom was lowered . . . I found myself in a meeting, talking about the design of our police vehicle seats, when the CEO asked, “Jacob, can you tell us if our product is going to pass certification testing?” FMVSS testing for seats includes a pull test where they pull on the belts with X thousands of pounds of force. This was my very first job, and up to that point I had been almost exclusively doing CAD work (solidworks) and DFM (I knew a lot about vacuum forming plastics). I answered that I could analyze our design and come back with an answer. I then pulled out some old textbooks to dust off some mental cobwebs and proceeded to do just that. This was a moment when I realized that even if I rarely used the stuff I learned in college, when I did there would be significant money on the line (testing was around $20k not to mention the success of the product). Those moments are why your employer hired a mechanical engineer rather than a draftsmen, an engineering technician, or someone who is “handy”.1
I’ve since come to think of these primary reasons for strengthening your analysis skills as an engineer:
- To predict – Will this part fail under this load? How far will this bounce if I toss it from this height?
- To optimize – Anyone can make a bridge that stands, it takes engineering to make the cheapest bridge that barely stands.
- To prevent guessing – Both you the engineer and others on the team are susceptible to “going with their gut” without an analysis
- To break away from how things used to be done – Understanding and using first principles allows you to escape from what was and understand what could be.
Can’t FEA/FDM/simulations/computers just do it for you? Yes and no. Quite often if it can be solved without a computer it isn’t really that interesting of a problem. However, setting things up in a computer takes time. Also, as of yet, computers can’t substitute in an understanding of the fundamentals of the problem. There are a lot of caveats to engineering theory. If you miss one in your simulation, all you have is a fancy random number generator.
A counterpoint – analysis is not an unmitigated good. It takes time (and therefore money) and needs to justify the cost. “Good enough” is exactly that and “perfect” is a whole lot more expensive. This also can specify what level of analysis is worthwhile: should I do some hand calculations, do I need to setup a simulation, etc.
One thing that I haven’t touched on, is that all of this analysis tends to strengthen understanding. Knowing the area moment of inertia of a beam lets me predict the stresses in bending. Knowing that the height increases the area moment to the cubed power means that I can instantly see how to change the L beam to optimize it for bending. As I more fully understand the principles I can solve problems at a run, rather than at a walk.
Wrapping all this up and connecting to improvement – I want to increase my ability to apply the science of engineering to my work in a productive way. Since I work for a consulting company, this needs to be a general improvement rather than just in a couple of areas. Over the course of this year I’ve had to figure out the stress concentration in a incoloy threaded pipe, the kinematics of a device tossed from a moving vehicle, and the stability of a small watercraft design.
Notes:
1. In the same breath of saying that analysis is one thing that separates you from other roles on the team – know that they have skills that separate them from you. The purpose of a team is to combine those skills to accomplish something better than you could alone. If you think you are better than the others you are going to hurt the team.