# Introduction This is a comprehensive list of all the things that make an excellent design, not just a good one, an excellent one. It can be products of all kind: technology, software, hardware, mechanical devices or really anything else. You can use it as a checklist or just pick a few points to work on. They're formulated as questions with short texts explaining what to do if you answer them wrong, some of them need testing, some of them you can answer on your own. They're not ordered in any way. I'm writing this mostly as a reminder to myself for when I'm designing things. But I thought other people could also use it. Or get an insight into what, at least I think, makes excellent design. Not all of the points are so obvious. # Ethics * Do the designers' and or the distributors' best interests line up with the users' best interests? If not perhaps you should rethink your company structure or funding methods * Does the product encourage behavior that worsens the lives of the users? (does it have a bad agenda) If intentional, fuck off. If not, this is a hard one to solve, solutions can be very subtle * Do the users have the option not to use the product? This is the classic thing about competition breeds innovation and so on # Design goals * First, what are the design goals? If you answered I dont know. Are you even doing design? (that was a philosophical question) * Are the design goals first and foremost about the function of the product? Form over function == bad design && Function over form == bad design. You need both function AND form in your design plan * Does the product meet its design goals? If not it's either the product or the goals that are the problem * Could the product be any simpler without becoming significantly worse? If you can make it simpler it's almost always the right thing to do. Often when you actually make a simplification, thinking that it'll make the product worse, it turns out that it made it better after all. Sometimes worse is better. Usually simpler is better * Is the product worse than the previous solution to the problem it aims to solve? If it is, find out why # Aesthetics * Is the product beautiful? In its entirety, every part of it? Design is hard, but if the answer's no, continue doing it. And dont ignore that one little part no one's gonna see anyways, someone will see it, it does matter * Is the above true for all senses? The sounds, the smell (maybe even the taste), the motion, does it feel good to touch, to operate, all of the senses matter. Aesthetics isnt only about the visual, design is not art # Usability * Is the product documented thoroughly to every user? It might be self explanatory, but it doesnt have to be, it doesnt even have to be intuitive. What matters is that every user can easily get a thorough, but understandable explanation of how to use the product * Can the product be accendentally broken or otherwise have reduced usability through normal use by non-idiot adults? A big fat warning might be all that's necessary, or maybe you have to "child proof" it a bit # Reliability * Will the product break itself or cause itself to have reduced usability under any normal circumstances? If that can happen it's not reliable enough * Do the users feel confident that the product will work properly every time they use it? If not it's not reliable enough * What class of nines does the product need to be in, and is it? Be a bit harsh on yourself here, because the norm isnt. Personally I'd say that 3 nines is minimum for non critical things and 5 nines for critical things => https://en.wikipedia.org/wiki/High_availability#Percentage_calculation Wikipedia article explaining what "class of nines" means * Is the product durable enough to withstand everyday abuse? Design is hard, but if the answer's no, continue doing it. I will add though, if the product is unavoidably fragile then you should design procedures or other products to keep it safe. For example: a CPU die is very prone to cracking if you overtighten its cooler, so you should design something to prevent overtightening, like a torque wrench # Lasting * Can the product be fixed/repaired by the user or a person of the user's free choice? Design is hard, but if the answer's no, continue doing it * Is the above documented properly? Then document it, and if that's too much of a pain that's probably because you got the above question wrong * Does the product contain any perishables that arent easily replaceable? This is kind of a sub question of the repairability one. Also think about your downtime requirements here, a perishable part should be quick enough to replace that you dont get too much downtime from doing so, or better yet no downtime at all. * Given proper care, can the product last (within reason) until the user no longer wants it? If the product is itself perishable: Is it easy to obtain a replacement? This depends a lot on what kind of a product it is (but it does also apply to software) # Feedback * Do you have a channel for user feedback? If not. Easy fix: create it * Do the users like the product? Find out why. The customer isnt always right, but they probably are * Can the users easily get high quality help if they need it? If you dont have a community to help you with this you'll have to do it yourself # Conclusion This wasnt meant to be an easy thing to achieve, there are a lot of points. But if you think I missed some let me know and I'll add or correct if I agree.