Beware cliched design rules
The teaching of 'design' often tries many tacks to impart knowledge to the student so that they can then produce a design based on sound principles. The rules - if you like.
More recently I have been the teacher and have been surprised by the intensity of the students seeking to find and file the rules. They want the manual on how to design things well. As an engineer I am probably as guilty as most in looking to put parameters around such a subtle process. Get into a design debate with an engineer and more times than not the engineer will be pushing for you to explain the principle on which you base your opinion. This isn't surprising as in the design process it falls to the engineer to crunch the numbers to make sure the product will not fail. A different take on 'safety in numbers' but none the less true. Who would want to travel in a bus where the braking power has not be calculated properly. Unless you're an engineer it probably doesn't cross your mind. This is the curse of the engineer in the design process. Pretty much everyone else doesn't even know what they expect of the engineer but if the brakes don't hold they will be telling them about it.
That is the invisible part so lets consider the visible part. The aesthetics of a design are there for all to see and anyone who cares to have an opinion about what they see can form it without any learned insight required. Or is it? Who knows what looks good? My observation is that the majority don't like things that are different or challenging. Designs that are different and challenging in their appearance can go on to become classics. Oakley Factory Pilot sunglasses were so outrageously different when they came out who would think that they would be the foundation product on which a company went on the be a dominant leader of a completely fashion and appearance driven market. I will not digress into how or why Oakley broke through with this improbable product but if you don't believe me here is the Tour de France leader Greg Lemond sporting the new fashion (c1989). Oakley went on to define numerous other 'looks' all of which have been copied. Anyway back to my point. What looks right and what looks wrong? What is right and what is wrong when it comes to looks? I'd better stop there I'm but an opinionated engineer.
OK, if you insist, lets take this a little further. I have something I'd like you to look at and form an opinion about it's strength for the job and how good it looks.
This is a pillar and arms from the departure hall at Melbourne Airport. What do you think? Here is another view.
Well I like it.
Do you? Post a comment and let me know your genuine thoughts at this point before you finished reading.
Why do I like it?
It looks good and the roof isn't falling down. Do you need any more reasons?
Well yes I think we do. So lets try and find some principles that we can check against this design on the assumption that it is fit for the job and (assuming some people agree with me and Melbourne Airport probably do) it looks good.
First the engineering. Here we have a cantilevered beam that is cantilevered from the pillar which is therefore point subject to the highest bending moment and should, following engineering principles have the highest second moment of area. In other words it should be fatter at the pillar. Just like the branch of a tree. Instead this design does the opposite of what is should do. From an engineering principled point of view this is opposite to how it should be shaped.
[Aside for engineers: We could argue that the cantilever is effective from the other end but if this was the desired approach then the connection at the pillar should be in the form of pin to allow no induced bending stress an they are not.
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With the fear of misusing a 'design' principle I will venture to suggest we consider "Form follows function". Would anyone consider the function is anything other than supporting the roof? This would indicate that the arms should be like the branch of a tree and thicker at he base and slender at the far end. Which they are not. I welcome comments on this interpretation of form and function.
But you see my point. There are two simple rules for design. One a formula the other a clear principle to follow and this design which has turned out well violates both these. How can that be?
I think that this shows how rules for design can be 'broken'. It is debatable if they are even broken in this example. The second moment of area at the base of the arms is high enough to do the job and aesthetically it looks good and I'm sure adhere to other visual principles I'm unaware of.
My conclusion is that by using design principles and 'rules' it should be possible to avoid mistakes but that does not produce an outstanding design. An outstanding design can comply with all the 'rules' but is not necessarily a derivative of those rules. Behind a good design there is always a good mind. All good design has a reason for being the way it is but that isn't always evident to even a learned eye. A designer or team must test their design against recognised principles and it must stand up but the application of those can be more subtle than at first thought as this example shows us.
