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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."
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.
.. 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
If you're an X Certified Y Engineer, you're a technician.
If you can be counted on to design a system that reliably works without killing people, you're an engineer.
If you can observe phenomena, reliably document previously unobserved phenomena, and from that produce useful but not mathematically precise practices or products you're a scientist.
If you can gather observed facts into a sheaf of postulates and a system of symbols that can predict unobserved phenomena, you're a mathematician.
If you can't do any of the above, you can always check bags at LAX for $150K a year.
If you can't get bags from the trunk to the belt, you might consider a position in middle management.
Help stamp out iliturcy.
Here is a formal definition of a Computer Software Engineer occupation, according to the US Department Of Labor:
"Research, design, develop, and test operating systems-level software, compilers, and network distribution software for medical, industrial, military, communications, aerospace, business, scientific, and general computing applications. Set operational specifications and formulate and analyze software requirements. Apply principles and techniques of computer science, engineering, and mathematical analysis."
OutputLogic
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.
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.
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.
That's pretty much how I think myself.
Engineering would stop being engineering if it becomes a science.
Engineering is in deep real world, with human nature and business requirements intervening all the time. Science (like religion) is in some sort of ideal world, vacuum, where all is simple and described by a formula. They are both trying to understand a problem - but from different angles. So different - or better say orthogonal - that they are guaranteed to cross only rarely.
Writing software is a creative process, arguably even an artistic one.
Same with science. I'd say that in the respect there is not much difference.
The difference is as I try to put it above is that in engineering "it must work," while in science it doesn't even have to compile. It only has to work in some ideal world with unlimited resources and non-existent foreign factors.
All hope abandon ye who enter here.
If you think K&R invented functional programming, you're sorely mistaken, Go look up people like Peter Landin and Haskell Curry. Secondly, if you think that the C language book has anything to do with Functional programming, you *badly* need to get an education with regard to what FP is.
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.
Science (like religion) is in some sort of ideal world, vacuum, where all is simple and described by a formula.
I think you're confusing (or conflating) science with mathematics. But don't feel bad; people do this all the time. Part of the reason is that science routinely uses mathematics as a tool, and the two fields are deeply intertwined. Scientists use math to help understand and explain what they're working on, while mathematicians routinely use scientific work as inspiration for new ideas to pursue.
But the "science" part is usually very much about the real world. It's the mathematicians who carefully avoid dealing with the real world, since that's not their job. The interesting part is how often the abstract, theoretical stuff that the mathematicians work on turn out to be very applicable to figuring out what's going on in the real world.
One of the problems with our terminology is that "computer science" is generally used for the abstract, theoretical part of software. This is misleading, because the subject really is a mathematical field, not scientific. If it were scientific, the computer scientists would be performing experiments and developing hypotheses to explain how software works. But that's not what they do; it's the "software engineers" trying to debug software that do things like that.
And this leads to the problem that "software engineering" generally involves doing things that in other fields would be called "science". In engineering, you are generally working with tools and materials whose behavior is well understood, so you can concentrate on design. With software development, this isn't generally true. An engineer designing a bridge or house or airplane can expect to work with detailed specs for all the available components. With software, the equivalent information is usually proprietary and intentionally hidden from the people building the code. Even in "open source" systems, the concept of "information hiding" is popular, and all too often this does mean that needed information is intentionally hidden from the person writing the code. So the software engineer is working with poorly-documented material, and must develop using processes that test and discover the properties of the underlying stuff.
Of course, there are some software engineers who don't do any debugging. But we know how well this works. Civil engineers might be able to develop this way, since they have access to full specs for their material. Software engineers can't, because they are kept ignorant of the details of lower-level stuff. As long as this is true, software engineering must have a large scientific component, to study and test the software as it's developed. They must constantly develop and test hypotheses about their code, in order to get it to function as desired in an environment that is mostly hidden.
Anyway, there's little chance of getting the terminology straight any time soon. There's no chance of software people getting access to detailed specs for the underlying systems. We even have laws in place that block the access to full information. So software engineering can't really be true engineering, and software developers will continue to spend large parts of their time acting as experimental scientists in order to debug their software. And they won't get much help from the computer scientists, who are spending most of their time working with the mathematics of the subject, while disparaging the real-world portion of their discipline as being "mere engineering".
Now if we could only get the computer field to adopt the same definitions that other fields of engineering, science and mat use. But that isn't going to happen any time soon.
Those who do study history are doomed to stand helplessly by while everyone else repeats it.
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.