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PhD Research On Software Design Principles?
cconnell writes "I am working on a PhD in software engineering at Tufts University. My interest are the general principles of good software design, and I am looking for links/references on this topic. The question is: What design/architecture qualities are shared by all good software? Good software means lacking in bugs, maintainable, modifiable, scalable, etc... Please don't tell me 'use object oriented methods' or 'try extreme programming.' These answers are too narrow, since there is good software written in COBOL, and by 1000-person teams for DoD projects. I am looking for general design principles. If it helps, I am trying to build on the ideas in this article from some years back."
Download the latest OpenBSD source code and read up. It's well written, well maintained and very well documented.
I mean what percentage of your PhD will be mine? Is it your PhD or our PhD. You want the degree, son? Earn it.
sed -e 's/Chuck Norris/Rajnikant/g' joke > fact
From what I can see, the real answer, process. Having a documented process that you follow to ensure that code is free of bugs, and that code is readable. How you accomplish those things isn't exactly important. For making sure code is readable and maintainable, you can have formalized code walkthroughs, or you could just have another coder read it over before it is accepted into the project. Ensuring that the software doesn't have any bugs is another issue. You should have a repeatable test environment, whether it be unit tests, or even just a list of actions peformed by an actual person, in order to check that everything is working correctly. Some approaches work better than others. But the real important thing in the end, is to have a defined process, and ensure that it is being followed.
Anthropic principle: We see the universe the way it is because if it were different we would not be here to see it.
Dear Mister PhD,
do your own damn homework.
Love,
the management
In my experience the single most important part to a software project is good requirement gathering and analysis. As for development, every program that i know uses some concept of divide and conquer. Breaking up a large problem in to a set of connected smaller problems simplifies writing good code. It's easier to write small bug-free modules then it is to write a large program all at once.
It would be interesting to find the cutoff point where a problem should be further divided and when it is discreet enough. Also, it would be interesting to know when a developer begins to introduce bugs or less optimized code. Like after x many lines or like y many hours.
It would be interesting to try and quantify code elegance. I forget who said it but there's a saying "code that looks good is good"
I came to the datacenter drunk with a fake ID, don't you want to be just like me?
Good software has:
Good software is written by good people. There is no general rules you can follow to automagically make your software good.
Sure some rules will tend to make your software a little bit better: KISS design principle, release early release often, unit tests, etc. But fundamentally it's all about people.
Then you might ask "what makes a good developer good". Well's that's not so easy to answer.
You can also end up with weird, inefficient code, because the specs are poorly written and no one is allowed to have enough oversight to realize it.
That's more of a management problem, I suppose, but I've all too often seen "glue" methods that were expanded beyond their scope due to the fact that the designers of Method A and Method C were never allowed to meet, and the people who came up with glue Method B were forced to all sorts of unholy kludge make them work with each other.
ad logicam Claiming a proposition is false because it was presented as the conclusion of a fallacious argument.
Most good software I've seen follows the KISS principle internally: Keep It Simple, Stupid. Pieces of it know what they're supposed to do and they do just that. They don't mix in functionality for several things. They don't have embedded knowledge of how they relate to the rest of the system. They've got clean, modular interfaces that let you test just that one part to make sure it's doing what it should and not doing what it shouldn't, without having to haul in large parts of the rest of the system. They either don't make assumptions about what the rest of the system will hand them or they've got those assumptions clearly documented in the interface and they test that their input conforms to those assumptions and produce a clear error if it doesn't. Eventually some pieces will have to embody the design and logic, understand how all the individual pieces fit together to make the system work, but that's their job: to orchestrate the work being done, not to actually do it.
Another indicator is that good software is designed with the certainty that it will change, that it will be extended and altered over time. Good software has that assumption built in. Bad software, by comparison, is often flagged by statements like "Don't worry, we're never going to change that." or "We don't need to worry about doing that.". Software designed not to change or be extended is either bad software or rapidly becomes bad software once it hits production.
And no, nothing particularly new there. It's been this way for about 50 years.
I strongly suggest you see if you can get a few weeks of academic internship with these people. Also know as 'Those who write the right stuff. They actually do know how to write software.
... whatever. And while people will start bickering that Apache or Blender code is oh so crappy in this or that area, rest asured that all projects of that kind, *incuding* the aforementioned *all* have core team members who are very well aware of the downsides of their software. And thus can help you out in your pursuit for details on professional software developement, because they also know the pitfalls.
Other places to look for: Linux Kernel team. Donald Knuths Tex/Latex.
Or, believe it or not, Blizzard Entertainment. They actually are the only entertainment software company I know of with a proven track record of extremely high quality software compared to others in the field.
But any core team of non-trivial low-level open source software technology will do actually. Python core team, PHP core team, your favourite Linux IO crew, Apache, OpenLaszlo, KDE, Haxe, Blender,
Bottom line: Join some tight crew of people that build stuff everybody uses or many people rely on to work. Hang with them for a month or two, then you'll have a better idea how exactly to approach your topic.
We suffer more in our imagination than in reality. - Seneca
The maturity of the management and its ability to insulate the coders from the noise from corporate is important to good code development.
Having an experienced architect is vital. Enforcement of the values of the team, especially with respect to interface specifications, is important.
Best regards.
I'm intrigued by this question, because I would assume that by the time you've reached this level (i.e. have a Master's in CS or something related) you would already have an idea as a starting point. Furthermore, I thought that the first part of any PhD-level research was an intensive Literature Review.
So, in other words, you should search LexisNexis, EBSCO, etc., and find some journal articles that talk about this. Read some books like Gang of Four or Mythical Man Month. Lastly, do your own data gathering. Find a bunch of Post-Mortems and start to put your own patterns together.
Oh, wait, all that would require work.
Seriously...I teach college-level courses and have multiple graduate degrees...and I'm continuously amazed at the quality that schools put out nowadays.
"You cannot find out which view is the right one by science in the ordinary sense." - C.S. Lewis on Intelligent Design
In some countries you have to submit a project in order to enroll into a doctorate programme, in others you become part of an ongoing project and your work will be a spinoff from that. Either way, I can't see how you are already working on your PhD and still making these sorts of questions.
You're a PhD student and you don't know this?
And you apparently don't know how to find it?
Hint: google for "Software Engineering graduate" to find grad classes in software engineering. Read their reading list. If that's too much effort, just read Parnas and Boehm to start.
It makes me sad that I can't get into a PhD program, with thesis topics already lined up to go, and you have apparently never taken a Software Engineering grad class.
Dear Slashdot,
I thought getting my PhD would make me uber 1337. Well, I finally got accepted into a PhD program, and now I find myself completely over my head. I don't even have a topic for my thesis!
Could someone do my homework for me? Also, could you supply your name, address and phone number? I'm going to need someone to go in and defend my dissertation for me. kthxbai.
Sit down because what I'm about to say is very profound and could make you tear up.
I've heard that the key to good programs is.......GOOD PROGRAMMERS
Beer! It's what's for breakfast!
If researching your Ph.D. thesis involves an "Ask Slashdot", change topics or drop out now. This is akin to asking the undergraduate Math club for ideas on your thesis, is it not? We are not (and should not) be anywhere near the level of knowledge you already have on this topic...
One of the most useful principles I've found for making "good" software is to design very clean, very powerful interfaces. Focusing on "modularity" often puts the focus in the wrong spot, namely on the center of the module. The point is that the details there *shouldn't matter* because you can abstract away all sorts of fiddly detailed functionality.
It is difficult to make clean and powerful interfaces, however. You really have to understand the nature of the problem you're trying to solve in order to pick the most natural groups of functionality. Very often, if you're trying to get something done in a reasonable amount of time and don't need to maintain the code for that long (though beware--you'll find yourself using, a decade later, programs that you thought you'd rewrite "next month"), it's better to code something quick and specific.
The cleanliness of an interface basically boils down to how little information you can pass to it, and how little information you need from it, in order for it to do what you want; and to what extent all information and data goes through explicitly defined interface elements (e.g. an interface in Java). (Here I'm drawing a distinction between data, e.g. the content of a character stream, and information, which is "hey, there's a character stream here, go work on it".)
The power of an interface basically boils down to how many different high-level operations can be constructed from mixing and matching components of the interface. For example, compositing operations tend to be powerful (e.g. take A, take B of the same type, perform some operation to produce C of the same type from A and B).
There are lots of other generally useful strategies, but I find this one of the most overlooked, especially by otherwise really talented coders (who can tend to make interfaces more complex because they are talented enough to work with something that complicated).
Why would a PhD student solicit for information on a social website? Shouldn't you be doing the research yourself??
It's been my experience that big software development companies almost invariably spend so much of their time worrying about those horrible real world conditions that it rarely occurs to them that those conditions didn't just happen by coincidence and that they could take steps to avoid the problems in the first place. Smaller shops tend to be much better at this.
Before anybody dives in and lectures me on scalability, let me say that IME the difference has a lot more to do with the kind of unprofessional, unproductive culture that can only thrive at mid-levels of large companies than anything to do with the scale of the project or the absolute size of the development team. Indeed, if you read the Bruce Webster article on a runaway project that was linked earlier today, it's pretty obvious that parts of the project code base were becoming unmanageably large because of incompetence and not because the project requirements actually necessitated that much code.
If you want to learn real world lessons, go watch a small- to medium-sized software shop, where there isn't space for the lazy and/or dictatorial idiots to hide, preferably one where everyone is a partner or there is some sort of profit-related pay so people have an incentive to really follow practices they think are helpful. Plenty of difficulties still arise in such environments, but they are much less likely to be own goals by the development team, and the team are much more likely to have effective ways to deal with them that would be of interest to others.
If you disagree, post your argument. (-1, Overrated) isn't your personal censorship tool for views you don't like.
Actually, when you realise what sort of horrors are present in a house you realise that the author of the linked document is drawing a false analogy. Both in houses, and in software, various shortcuts are taken for pragmatic reasons, and these are often because the shortcuts do not undermine what is the primary function of the "house" or the "software". For example, the concrete floor in my house is lousy rubbishy stuff. Probably doesn't meet the codes, yet except when the carpet layer has a hard time laying I never notice, nor really am I too concerned, about the failure to meet some "ideal" standard. So in doing research in this area, a reality check is required and the article you have chosen to refer to starts out with a poor example to prove a point ... I am not convinced.
I think the parent would be better contacting slashdot admins to mine the postings rather than an article thrown out there.
He's asking the wrong question the wrong way for the level of work he should be doing. Probably because he's got "book" experience, and not 10 years of work experience. That said, you won't find many people teaching at university that would do any good answering his questions either. They may be good at their jobs, but not at multiple project managements... the ones that are really good don't teach.
I think that shows the problems with computer degrees in general. They don't really teach long-term project management in university (it's beneath them). They want to teach you lots of great theory, but just expect you to learn how to USE it thru osmosis. Something like a PhD for software engineering really shouldn't be offered to anybody with less than 5-7 years working at programming and managing programmers.
Most bad software is rushed, created by bored programmers, in a corporate decision to create another boring and faulty-by-design software system.
Most good software is written by a small team of very excited developers who love what they do, are given the resources to do so, and who couldn't even think of a more exciting system to build.
You can add all the modularity or simplicity or readability or whatever you need, but unless it is made with love, it won't be beautiful.