A few years ago I studied engineering at university. For four years I learnt a lot about a whole range of different topics. Some of them interesting, some of them less so. I had a lot of friends studying other subjects, like physics or mathematics, and quite often we would cover the same material. We would be taught the same theories, principles and methodologies. Yet, our notes always looked different.
We would have different versions of Schrödinger’s and Bernoulli’s equations (the engineers version always looked the most friendly). It turned out that most of the time for real world design, the engineers version was accurate enough.
On the day that I graduated I remember one of my professors saying “You know you’re a real engineer when you can work out the area of a 9cm diameter circle”. Now, he wasn’t talking about just being about to work it out (that should be pretty simple for a bunch of students coming to the end of their technical degrees). He was talking about finding the answer instantly, with a minimum of fuss.
A mathematician or a physicist tend to answer that question quite precisely, and end up somewhere close to 63.6cm2. They usually work everything out properly and do 3.1415 x 4.5 x 4.5. Of course, this is the right answer and all is well.
An engineer on the other hand (whilst well capable of working out an accurate value) tends to give the answer 60cm2. Making appropriate approximations, pi ~= 3 and 4.5 x 4.5 ~= 4 x 5 – the whole equation becomes much easier to solve in an instant. 3 x 4 x 5 = 60cm2.
That is not to say that attention to detail and accuracy have no place in engineering. In fact, they are incredibly important a lot of the time. However, a good engineer is able to navigate both the big and the small pictures. He/She is able to work out when it is appropriate to be detailed and when it isn’t.
Engineers live firmly in the real world. Good engineers know that sometimes, rough and ready is good enough. Sometimes complex models and predictions are way over the top. Sometimes we just need an answer quickly. Let’s not waste time and money by diving down to low level detail out of habit. Let’s only do it when the situation calls for it.