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How Software Engineering Differs From Computer Science
cconnell sends in a piece he wrote for Dr. Dobb's which "argues that software development will never be a fully formal, rigorous discipline, and the reason is that software engineering involves humans as central to the process." Quoting:
"Software maintainability, for example, is the ability of people to understand, find, and repair defects in a software system. The maintainability of software may be influenced by some formal notions of computer science — perhaps the cyclomatic complexity of the software's control graph. But maintainability crucially involves humans, and their ability to grasp the meaning and intention of source code. The question of whether a particular software system is highly maintainable cannot be answered just by mechanically examining the software. The same is true for safety. Researchers have used some formal methods to learn about a software system's impact on people's health and property. But no discussion of software safety is complete without appeal to the human component of the system under examination."
How about a rigorous, ever changing, ever intriguing discipline? It already is and will be more so.
sudo mount --milk --sugar
Going by the wikipedia definition decisions made in typical software development cycles don't seem to rely on a justification based mathematical or physical analysis. Admittedly I might be generalising, but is it more of a soft-skill then? ie something that you acquire on your own rather than something that can be formally taught or imparted as training? Makes you wince when you see all those job adverts asking for programmers to work in their "engineering departments"... Disc: I'm a coder myself, working in a structural engineering environment, so watching people design buildings around me feels more like "real" engineering... Go on, mod me down now.
Humans are not maths.
.. to become a rigorous engineering discipline. It's not quite there yet. I am not convinced that it ever will be. Writing software is a creative process, arguably even an artistic one. Well understood rules can be followed, provably correct algorithms applied, formal design methods used, but it is still a human creative process, and as such, I suspect inherently non-rigorous.
Computer Science compared to Software Engineering?
Think aeronautics. The science of aeronautics ponders the laws of aerodynamics and the laws of flight.
Engineering aeronautics is all about building the damn aircraft.
Trying to associate Microsoft with "fun" is like trying to associate Satan with aromatherapy. -Tycho
So, I'm sure, are a lot of things I don't recognize, like designing a sky-scraper or space shuttle.
Programming is an art, Anyone can follow instructions and follow an existing style or try to paint a realistic scene, but to come up with a skilled interpretation that really conveys a meaning takes a better painter. To bring together 20 painters, outline a collaboration and manage the production of some giant, detailed interpretation takes a master--at this point natural talent starts to mean more than training, and no level of training can improve someone without talent.
Anyone can write a small program. You can fit 20 generic programmers in a room and have them each write a small program. You might even be able to get them to join the programs somewhat-properly, but the whole thing will never go smoothly.
One or two really good programmers will probably out-produce 20 people that "know how to program".
How many amateur painters do you need to create something like the sistine chapel?
Just because most people can't see the art that allows large programs to work doesn't mean it's not there. In fact, most people can't tell any type of good art from bad without some training.
A computer science graduate creates the perfect program, then a software engineer goes and breaks it by making usable.
Don't we all need more experience?
The basics are pretty simple. And by the basics, I mean where Niklaus Wirth got his ideas for the mathematical basis for algorithms, Alan Turing.
Then we learn about functional programming from the guys who invented it: Kernighan and Ritchie. Grok lex and yacc and we're halfway there. After we've written three or four languages we realize their purpose is to formalize our interaction with libraries of prewritten code. Along the way we learn about the importance of portable compilers and the interdependence of portable compilers and portable operating systems and libraries of prewritten code, and the importance of all of those to the persistence of data.
Then we study the evolution of C++ and figure out by ourselves why its inventor Bjarne Stroustroup is a brilliant idiot. (Hint: it has to do with interface hiding).
We join the ACM and read and understand their Communications up until 1990 (anything after that is encumbered by patents). This takes a very long time.
And then we invent some stuff and every fool that just got his AOL account feels qualified to call us an idiot because we didn't do things the way he expected.
How about a rigorous, ever changing, ever intriguing discipline? It already is and will be more so.
It is. You were right.
Help stamp out iliturcy.
...is about a 1000x difference in cost per line of code. There's a lot of pure software engineering going on out there, but the products are relatively few (and usually heavily re-used) because the cost of being reasonably certain no one will die is really quite astronomical. Most people who call themselves software engineers with a straight face are really doing something in between, which is why we have entire libraries full of books describing methods that trade off varying degrees of safety for economy.
In one sense, software engineering can be considered a more formal discipline than other forms of engineering, because software engineering has studied in much greater depth the tradeoffs between formality and economy, since the spread between them is so much wider.
There's no failure quite as dissatisfying as a complete and total solution to the wrong problem.
The TFA, and any other such articles, amount to nothing other than navel
gazing. People who think they are a scientist/artist/whatever, thinking it
makes them more leet if they are able to exclude others.
The elitist attitude of contemporary science is something which I hold in
extremely deep contempt, to be blunt. Programming might not be considered a
pure science, if they want to try and claim that anything that
human beings do is completely free of emotion. Nothing does, so by that
definition, nothing is a pure science.
If you focus on the purely mechanistic/mathematical aspects of programming,
that can be considered science. If you focus on the emotion, or the level of
inspiration which sentience is considered a prerequisite for, it's an art.
Use whichever term for yourself that you want, or better yet, just be
you.
Remember Napoleon, people. The greatest Emperors crown themselves.
There toward the end I meant to post this Zen summary:
After all that you begin to realize that the more you know, the more aware you are of the vast expanse of things you don't know. And then I arrive at what you said in 16 simple words, by a long discussion. I guess you're smarter than me.
Help stamp out iliturcy.
Seriously. CS asks questions of the form will X accomplish Y? Software Engineering asks questions of the form "what is the best way X to accomplish y"?
Nothing to see here, move along.
Some of these same old complaints exist with hardware too. It takes humans to detect the "bugs" in a circuit layout or to quantify how adaptable/modifiable it is (ie, maintainability). There's guesswork involved in figuring out how much to over-engineer something, finding the cheapest part that does what you need, crossing your fingers that a vendor doesn't discontinue a component. Hardware engineers may take a more rigorous approach than the typical software grunt, but it is still a human endeavor. Otherwise we couldn't have nearly so many board revisions and software wouldn't be used to mask over the hardware shortcomings.
The biggest problem with software is that it is easily malleable. We'd have far fewer bugs if it were treated like hardware that couldn't just be tweaked in the field if something is wrong; we'd be given more time to finish the designs and implementation, the testing would be built in and mandatory, nothing would be declared finished until several eyeballs looked it over and even then that would just be the initial prototype, and we'd have outside testing companies verify the solution for compliance with regulations. When software is malleable it's really hard to tell the bosses "sorry, we can't make that change" or "we can't ship this week because we added a bug fix and have to retest." Actually the same pressures exist in hardware (and other engineering discliples) it's just a lot more common with software.
Except architecture is a highly regulated and licensed profession, whereas any schmuck can write code.
Slashdot - The great and glorious cluster fuck of Internet wisdom.
Let's face it. Most (if not all) programs we write are "made-to-measure" software, not mass production programs. You need craftsmen for that. Artists are usually only interested in the looks.
Software development is a skill that can only be trained. Trained to think like a hacker, to think like a newbie user, tothink like a client (client!=user), to know when to optimize and especially when NOT to optimize, trained to think in modules and their relations (I encountered far too many programmers who have difficulties with this). Trained to think in responsibilities. Trained to abstract. Trained to trust the unit tests. Trained to write them.
A good programmer is a craftsman. Someone who can build the wish of a client not exactly as the client has sketched it, but as a robust and working structure that does what the client wants.
An artist is someone who designs the famous "Z" chair and dares not sit on it.
A craftsman is someone who takes the idea of the "Z" chair and dimensions it right so it becomes a chair instead of an idea.
Software Engineering = fashion
Computer Science = maths
Simple. Nuff said.
Zen tips: Pay attention. Don't take it personally. Believe nothing.
Yep to me Software Engineering is more like Design.
:).
The Architects design stuff, and the Builders build it.
The Programmers design stuff, and the Compilers build it.
The trouble is too many people don't get it and manage software projects the way they manage the Build phase of a civil engineering project. When they should be managing it the way they manage the Design phase.
The build phase of a civil engineering project can involve scores of workers and heavy machinery.
The build phase of a software engineering project involves the programmer typing "make all" and going to fetch a coffee.
The big problem:
Civil Engineering: build phase costs 10-100x design phase
Software Engineering: design phase costs > 1000x more build phase
And that's why Management ends up shipping the "plastic models/blueprints" as v1.0 since they compile and kinda work.
How software engineering differs from computer science is similar to the way civil/mechanical engineering differs from math.
Engineering does involve math, but a lot of times you don't really do a lot of math - something else does it for you
Same for software engineering, 90% of the time you aren't doing the "pure CS" stuff- sorting algorithms, info theory etc.
You're doing stuff like figuring out how to talk (and what to say) to some database or Active Directory, or whether the API for something is documented (correctly) or not. Or creating a brand new protocol that is not too inefficient and mere mortal programmers can use without screwing up.
The problem is that that was not a shortcut.. it was a humongously wrong statement that shows you probably do not understand the concept you're mentioning.
I want to play Free Market with a drowning Libertarian.
Whereas computer scientists go into research or teaching - to produce more computer scientists.
politicians are like babies' nappies: they should both be changed regularly and for the same reasons
As a degreed engineer with 30 years of work in computer hardware and software, I firmly believe there will be no such thing as a "Software Engineer" until such engineer has a "PE" after his/her name. That's "Professional Engineer" (wiki it); a responsible party who can be put in jail if the software kills someone. There's nothing like the threat of punishment to put rigor in your processes.
If you're going to insist on rigorous naming, you ought to be consistent about it. Programming != "the IT crowd". There's some overlap, but there's a lot more programmers not in "the IT crowd" and a lot more to be done than programming within the "IT crowd".
Furthermore, I don't care how many bridges, buildings, or aircraft you can design, if you can't drive a steam locomotive (with attached train), you ain't no engineer.
If a student can't learn the basics of computer programming as part of a four-year program (whether CS, CE, or SE), perhaps programming isn't the field for him.
Unfortunately in this imperfect world, there's few such research positions available. But they aren't nonexistent. (as far as I'm concerned, you can have them, I prefer to get my hands dirty with code :-) )
Different kind of law. Moore's law is more like Murphy's than Newton's.
Nothing magically grants you "the ability to design large or complex software systems", no matter what degree or title you have.
All this discussion about Computer Science vs. Software Engineering vs. Programming is really about ego and will not lead to any improvement in any discipline.
I think the real issue is there is no 'routine' aspect to software.
Most other domains of Engineering have a very defined field and set rules. There are also very standard way of doing things. Simulators have been built...
I would argue that anytime some *new* device in another field of engineering is done, it suffers from the same 'flaws' as software. I can't speak for too many other fields, but I can speak for electrical engineering. Any new kind of hardware follows the same kind of iterative, simulate, debug... aspect as software. Fortunately, for hardware it needs to accomplish its set goal and people recognize the costs involved... and it somehow managed to escape the anyone can code mentality.
Now software, we must understand is be definition new. ANY repetitive work is done by the tools (compiler, linker...). In Civil Engineering, you still need the civil engineer to oversee the building of the structure. To make sure the workers do things correctly... this is all very routine work. Often there are standard blue prints already done and the civil engineer just makes some small tweaks and then has to oversee the project. Just follow the damn process. In software, we are so fortunate, that our builders (compiler, linker...) work amazingly well. They never make a mistake and can repeat their work as often as possible.
Once built, software can be deployed a million times over without fail. Not so for civil engineers who must pursue the same rigor each time a building is built.
Heck in software, we like to make one deployment so flexible by these amazing things called 'options'. everything is a bloody option and configurable. Again, unlike many other forms of engineering where the regularity and standard process dictates how things are done.
We must understand this key difference. Because of the nature of software, *some* people have made the mistake of trying to superimpose other disciplines onto software.
There are those who would say that software is design and implementation.
First you design it, like the civil engineer designs the building.
Then you implement it, like the workers build the building.
I cringe whenever I hear a similar analogy. Yes, there is some 'abstract' notion of design away from a specific language, but expressing that design in a particular language is still design.
The civil engineer who uses autocad or whatever to design their building is expressing his design in that format.
The software engineer is just expressing his design in C++/Java...
THERE IS NO IMPLEMENTATION WORK IN SOFTWARE.
Everything is design. Just high level design and low level design.
Sadly, some people continue to try and draw parallels with factory or civil engineering work. They claim there is some design that can be done, and then a bunch of code monkeys (construction workers) assemble and build the software. It's so wrong on so many levels, I'll repeat it again. The compiler and linker assemble and build the software. Every code monkey is doing design.
For sure, I think we will get *some* formalization of the process as certain practices become more standard. Our tools will most certainly become better and better (issue trackers, source control...). Yet at the end, the code still needs to be designed. There is no escaping the need for good software engineers.
Just like there is no escaping the need for good civil engineers if you every try and do something out of the ordinary.
I could write more about formal testing and the like, but I'll leave this point as is.
More specifically, an Engineer is someone who can claim that a system won't kill people and can legally transfer the responsibility for the lives of the users from the construction company to himself. What we don't have in the software industry is the accountability that forces Engineers to be rigorous. Sure, we software developers can claim that we use rigorous processes, but every time something doesn't work, we shrug it off and get to work on the fix. If a real Engineer screws up big just once, he loses his license and/or goes to jail.
What makes licensed Professional Engineers so mad about the computer industry's flippant use of the word engineer is that it dilutes the title that they worked hard to obtain and that gives them a very unique position of responsibility in certain aspects of life. Don't think of an Engineer as someone who is good at any specific thing, think about them as a gatekeeper of the use of technology in public places.