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"Just the other day I burnt a vessel because I had switched on a wrong burner which had en empty vessel on it. So there is a problem. And I am sure there are lot of people like me who get confused with these things, just like the Norman door"
I was reading the book https://en.wikipedia.org/wiki/The_Design_of_Everyday_Things, this book is a must read for all the wanna be designers/ architects of software systems (or even otherwise). This blog is highly inspired by the preachings in the book.
These days I am regularly challenged by an "everyday thing", the Gas Stove at our kitchen. For all those westerners out there, my part of the world still uses the Liquified Petroleum Gas(LPG) for everyday cooking. So this is something still relevant for most people living in this part of the world.
We use a 4-burner gas stove in our kitchen. A top view of this stove roughly looks like Figure-1 shown below. The four hollow circles represent the burners and the four-filled circle on the right represent the knobs to switch on these burners.
Figure-1
So where is the problem, you may ask? When I first used this stove, I had a near accident. I was leaning close to one of the burners and turned one of the knobs to switch on another burner next to it. It turned out that the burner closest to my face was the one that got switched on (auto-ignite mode burners, not the match-stick-lighter types). It nearly burnt my eyes, it was an embarrassment. Obviously, I could have used caution, the mistake was on my part. But even after 2 years of using this stove, I occasionally (1 in 20 times) get confused and switch on the wrong burner. Just the other day I burnt a vessel because I had switched on a wrong burner which had en empty vessel on it. So there is a problem. And I am sure there are lot of people like me who get confused with these things, just like the Norman door mentioned in the book I stated at the beginning.
I had to device a way to easily remember the knobs to correct burner. How I remember now is, by dividing the burners and the knobs into two halves, like shown in Figure-2. By doing this my chances of using the right knob increased from 25% to 50% (i.e from 1 in 4 to 1 in 2 ). You get the point?
Figure-2
Once I divided the stove into half, I could remember that the top most knob of the top half belonged to right most burner of the top half and the bottom most knob of the bottom half belonged to right most burner of the bottom half. Sweating? It’s easier than explained, so the Figure-3 is the correct numbering of burners to knobs.
Figure-3
So, now I am reasonably good at using the correct knob for the correct burner. But it’s still not 100%. I always thought there is a much better way to design the layout of this gas stove.
The most perfect design, according to me is the one shown in Figure-4 below
Figure-4
Notice that every knob is closest to its corresponding burner, so there is no confusion here. The layout is crystal clear. But sometimes, the best design is not practically feasible. I would imagine that the electrical wire which lights up the sparks for the burner to ignite would crisscross the gas pipes underneath. I guess there must be a reason why the 4 knobs should be reasonably close to each other, just my guess here. So, we have to design the next best solution which keeps the knobs together instead of being spread apart. Let’s discuss it in the next few sections.
As shown in Figure-3, let's number them so that we know which knob is for which burner.
Figure-3 (again)
It's an option, but when you look at the two knobs in the middle, it's not very intuitive. Check the below Figure-5
Figure-5
Is this knob for burner 1 or 4? You will eventually know when you look the way numbers are oriented. The numbers are oriented along the line of the knobs. This can still be confusing. There is scope for improvement here, right?
Here is an improvised version in Figure-6. Notice that the numbers are away from the orientation of the knobs and are to the right of each knob.
Figure-6
This is getting better and better now. But is this the best? Not yet! It is still slightly confusing with all those numbers for the burners in one way and the knob numbers in another way. Agree? Still with me?
How about this (Figure-7)? This is lot nicer. Those picture of knobs with blue filled circles indicating which burner the knob corresponds to? Drawing is the language of engineers, picture speaks thousands words (although in this case only four numbers)?
Figure-7
But then the orientation of the picture and knobs are along the same line, much like the numbered design we discussed in Option-1 (Figure-3). As you guessed it, it's easier to improvise this.
Here we are. Figure-8 below is as good as it gets. The little mapping of knobs-burner picture is on the right of each knob. Very less confusion here.
Figure-8
But then, do we really need even a picture for our best design. Like the most ideal design discussed a while back, can the design speak for itself? Like the doors discussed in the holy design book mentioned earlier?
What about this? Look at Figure-9. The knobs are exactly oriented like the burners. The knobs are all close together. The design is intuitive and more importantly practical.
Figure-9
I think this is the winner under the given constraints. Do you agree?
So, we have seen how an everyday thing like a gas burner can be designed better through a series of improvisation. In the software design, you would also come across situations like the analogy explained above. There would be bad designs, there is a most ideal design which may not always be feasible and then there is a best design under the circumstances. In the book https://en.wikipedia.org/wiki/The_Design_of_Everyday_Things there are several other examples and principles explained much clearer than this. I suggest you read the book, if you liked this small (?) blog.
Well, it's time to cook now... using the same stove... and hopefully without burning another vessel ;) See you soon with another blog!