There's no shortage of writing about industrial design including some attempts from me in the past. By in large, there are posts about CMF, tons of sketching tutorials, thousands of rendering videos on YouTube. There are also DFM/DFA checklist. I had created one myself. They are good, yes but and almost none of it connects to anything. Like a single product to anchor all of them to.
In college, sketching is one module and CAD is another and materials is a third, and there would be graduation project where one's supposed to bring everything together in an ideal manner. That formula breaks in real life, at work scenarios. So people come out able to do eight things separately and none of them in order, with a portfolio of many concepts in it and not one object taken all the way to a real factory floor.
So I thought of trying something different here. What if we take one object, start to finish, in the order the work actually happens, with every stage handing its output to the next one. And since I'm not a trained industrial designer, I borrowed the teaching from Dieter Rams', Jony Ive's, and James Dyson's works. All the people I'd want in as mentors anyway.
Let's start with a simple, but a close-to-my-heart, object. A water bottle.
It's a good thing to learn on for four reasons. It's simple enough to hold in your head all at once. It's hard enough that, in my opinion, almost nobody has got it right, which you can check yourself by opening your own cupboard, or mine - I have a ton of water bottles. Everybody in the design room has used one, so it's a heavily familiar object. And it's cheap enough to prototype that you end up building instead of arguing in meetings.
Stage 1: Research & observation
I own 10+ water bottles. The modular bottle set and the Apple smart bottle cost good money but the ones I carry are neither of those two, and I didn't think about that until one Thursday morning when I was packing for the office work trip and I picked up one of the plain ones with slightly scratched base instead of the TMB and Apple's. But the expensive ones are better made with better steel, better paint job… and I don't carry them. It's mostly because the grip feels off with the two, they require effort in either opening or closing the spout or is a hassle refilling.
Asking doesn't work
Ask somebody what they want in a bottle and you get leak-proof, keeps water cold, easy to clean. All three are true and all three are useless, because nobody has ever asked for a leaky bottle that cooks the water, and every brand already assumes all three solved anyway. There's a politeness thing on top of that which I think most research training underestimates in Indian homes. You're a guest, you've been given tea, and the person is not going to tell you that the thing in their bag annoys them every single day. They'll say it's fine. And then they'll show you it isn't, in the way they wedge it into a side pocket, or in the mug of water sitting next to it on the desk, or in the black ring inside the gasket they spotted a while ago.
People answer questions about products with opinions, and opinions come out of the part of the brain that wants to sound sensible. What they actually do comes from somewhere else.
How I'd run it
I'd speak with six to eight people for at least ninety minutes each before I stop and look at what I've got. After talking to six folks is roughly where things start repeating.
Two of us go, one talking and one recording, and the person recording says nothing at all. The first ten minutes are tea and nothing else beyond the formal meet-and-greet. Then there's really only one sentence I need, which is show me how you filled the bottle this morning. This would be different from asking how they use it. It's about how they actually fill the bottle, this morning, with the real bottle and the real tap.
I would take photos/ videos of hands and not the face as people get conscious around camera and they'll likely not allow you to photograph them. But hands don't know how to pose for camera so it's easier. Then you shut up for a while and let the user do their thing even if they go silent. Maybe count till eight after they stop talking to nudge or continue talking further. But focus on observing.
You see… if you observe anything in daily use, it's more accurate than the person talking about it. For instance, take rubber bands. If someone's using rubber bands around a lid, it means the thread has gone loose, or the grip is slipping when wet. If you see a bottle on a counter next to a glass of water, it means the bottle is a reservoir and the glass is what people drink from.
Similarly, if you open a six-month-old bottle and if it smells then the neck is too narrow and gasket has been damp since. Take a note on the geometry of the neck here. Don't forget where the bottle travels throughout the week; it will tell you a lot about the size. It goes into bag pockets, cup holder, on the desk, in the fridge door, and how one carries the bottle to the bag, the cup holder, or to the desk.
Write down what you can design against
A detailed report of all user visits containing tons of data, factoids, and insights and observed things in a database format is a database for future evidence mapping. Nobody can start designing basis that. Instead write down what happened with a count and number attached. A made up example could be like:
Six of six opened the cap with two hands, every time, to fill the bottle. And three of those were standing up with a bag on the other shoulder. On an average, turns to open the cap was about 2.6. All of them put the lid down on the counter, wet side down, while they filled with one raised shoulder to balance the bag. Two of six kept a separate mug at the desk and used the bottle only to fill the mug.
I'd also carry a measuring tape and a kitchen scale. This is to measure simple daily objects like cup holder, fridge shelf, bag pocket, bottle neck opening, and the clearance under every tap the bottle has to go under. I'd weigh it full and empty. That I can design against, because it has a count and a measurement and a consequence in it.
Now, an important thing. The above becomes a good list and if designed against the above, it'll produce a bottle nobody remembers, unfortunately. Because a list is a set of things to satisfy which gets you a slightly better version of what already exists. Now how to get to produce something unique?
To find it I put all the observations on one page and look for the problem that shows up everywhere but isn't categorised yet. Things like the cap is usually kept face down on a counter that gets wiped with the cleaning cloth. Or the fact that the gasket is not easy at all to take out and clean and put back easily and forms a blank ring in a few weeks which leads to bad smell.
The lid should only come off to be washed
I like some of the bottles I use but I don't like that I have to unscrew the cap to refill them. It's simply not convenient. The answer could be that I stop taking it off and only do so when it needs to be washed.
These bottles have a button. You press a button, a spring-loaded buckle lets go, the cap hinges back and you drink from the spout. You should be able to refill through the same opening without unscrewing anything. The cap should come off to be cleaned and for no other reason at all.
Which kills two failures at once. A cap that never comes off never goes face-down on a counter, and it never sits wet in a drying rack either, so one of things that makes a bottle smell by month six mostly stops happening.
So the clear problem statement I'd write is that the lid only comes off to be washed, and everything else is a container. Now, look at the beauty of this framing. The cap thread is now a service part rather than a daily one, so it can be slower and tighter than it would otherwise be.
Two more things the bottle should do
You have to be able to see the water. I've always been opinionated about this. An opaque bottle is a closed vessel and it doesn't remind you to drink water (out of sight, out of mind). A clear bottle makes the water visible and it's a direct reminder to drink water.
Then, filling water is a task, so do it less. The one irritant I have with the bottles I like is that they are all sub 750ml bottles. I have to refill them about four times a day and I skip most of the time because I'd be on a different floor. A litre bottle roughly halves that need and keeps one hydrated without the effort of refilling.
Now finally, the brief
Design a one litre bottle with clear body, and a spout you open with one thumb and never unscrew to drink from or refill. The cap or lid only comes off to be washed. The bottle is wide enough at the neck for a hand and a cleaning brush. It should standing under an Indian kitchen tap without being tilted. The bottle should be identifiable across a room as yours. It should have something to hang it from. The bottle should not have anything on it that can't be taken apart and washed.