Archive for April 1st, 2014

Musings on The Mythical Man-Month Chapter 1

Summary of the chapter:

Growing a program

A standalone product, running on the dev’s environment, is cheap.

It gets expensive if:

  1. You make it generic, such that it can be extended by other people. This means you have to document it, testing it (unit tests!), and maintain it.
  2. You make it part of a larger system. For example, cross-platformness. You have to put effort into system integration.

Each of those tasks takes ~3x effort of creating the original program. Therefore, creating a final product takes about ~9x the effort. Suddenly, it doesn’t look simple anymore.

Why Software

  1. Sheer joy of making things. Especially things that you make yourself.
  2. Joy of making things for other people
  3. Fascination at how everything works together
  4. Joy of always learning
  5. Joy at working in an insanely flexible medium – a creative person, but the product of the creativity has a purpose. (Unlike poetry, for example)

In summary, programming is fun because it scratches an itch to design and make something, and that itch is surprisingly common among people.

Why not Software

  1. You have to be perfect. People introduce bugs. You are a person. Therefore you aren’t perfect, and a paradox occurs, which resolves in the program being less than perfect.
  2. Other people tend to dictate the function/objective of the program – leaving the writer with authority insufficient for his responsibility. In other words, you can’t order people around, even though you need stuff from them. Particularly infrastructure people, given programs that aren’t necessarily well working and they’re expected to make them run.
  3. Designing things is fun. Bug fixing isn’t. (This is the actual work part.) Particularly where each successive bug tends to take longer to find & isolate than the last one.
  4. And when you’re done, frequently what you’ve made is ready to be superseded by a new better program. Luckily, that shiny new thing is usually also in gestation, so your program gets put into service. Also, it’s natural – tech is always moving on, unlike your specs, which are generally frozen at a fixed point. The challenge is finding solutions to problems within budget and on time.

So I got ahold of the much talked about Mythical Man-Month book of essays on Software Engineering… and I’ve decided to read an essay a night, and muse about it, after writing a summary of the chapter (read: taking notes about the book, so I’m not just passively reading).

I agree with pretty much everything – and I’ll cover points in order of where they appear in the essay.

Growing a Program: The extra work done in getting systems integrated is pretty accurate. I think that’s driving a lot of the move towards offering everything as services instead of one monolithic thing. Moving to using a service means a lot of stuff is abstracted away for you – you can ignore the internal workings (more so than using a library, which you have to keep track of) in the hope that stuff works as advertised. So you save some time on the integration side of things by reducing the amount of surface area you have to integrate with.

However, the fleshing out of the program – writing tests and documenting everything, is harder to avoid. A lot of the boilerplate stuff is automated away by IDEs (auto generating test stubs, for example), but there’s still work that needs to be done to make stuff into a proper dependable system – and that’s really the stuff that’s separating the small scale, internal software from public scale.

Admittedly, that’s a bit of a tautology. But I think a lot of the growing is just forced by not wanting to keep on fixing bugs in the same code. By having a test against it, you know whether or not at the very least, the expected behaviour occurs.

Why software: I chose software over hardware in Uni because it’s so much more flexible (#5). I like making things (#1), especially those things which help people (#2). I do a mental happy dance every time someone posts a nice comment on Lightroom Plugin page on deviantArt. Though the happiness of understanding how things fit together (#3) is more of “Ha! Got <complicated API> to actually work!” And #4 is more frantically Googling so as to not look like an idiot to the rest of my team.

Why not Software: Uh… yeah. #1 & #3 – damn bugs. See the 6+2 stages of debugging. Sadly true, especially the moment of realisation, followed by how did that ever work. But fixing bugs is satisfying, particularly a new bug that you’ve never seen before. #2 – That’s, well, the nature of work when you’re not at the top. The authority/responsibility trade off is real. I like to think I’ve worked around it at Twitter by following Twitter’s “Bias towards action” guideline – I have submitted fixes for other projects, gotten reviews and submitted code. Much more efficient than filing a bug and saying “BTW, you’re blocking me right now.” And #4 – That goes along with the learning new stuff thing. Also, it’s probably a good thing that a new version will come along soon – you get closer to what the user wants by iterating. If you’ve stopping iterating, the product is either a) perfect, or b) cost/benefit analysis says it’s not worth updating, run it in pure maintenance mode.

Or c) you just really don’t care about it anymore. Which is really just a variation on b.

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