Sunday, September 20, 2009

Agile, but...

I've heard a lot about the poor effects of "not doing Agile"--that is, doing Agile, but...

These practitioners have a set of expectations around both process and performance. The problem I have is a huge lack of comparative data. When a team is delivering software, it's the rare business that's willing to risk productivity for an experiment to answer questions like "if they can produce x per week under process y, does x decrease if we drop agile practice 'z'?".

When I joined my current project, we were being managed in a barely-recognizable devolvement from scrum. We stopped doing stand-up meetings daily about 4 months ago; we stopped doing status meetings every other day about 8 weeks ago.

Is that negative stuff? I don't have any data either way, but I don't think so. In fact, I think we could argue that we are using exactly the agile things this team needs and can use effectively:

I delivered a formal design document about 2 weeks ago, just in time to start coding for this release cycle. We don't do much formal design, though; we mostly work from a domain model, process specifications, and FitNesse tests. Sometimes, though, you need words-in-a-row and UML diagrams.

We went into code freeze last Friday, limiting check-ins to bug fixes and test fixtures. The following Monday we received several new requirements. Since code freeze, there have been updates to something like 9 process specs. Most, if not all, of those changes will be in the release. We'll probably be in code freeze for two or three weeks, which is a lot in a six-week cycle. We're treating the new requirements as bugs, and to be fair, they're about the size you'd expect from a functionality bug.

We're delivering new functionality at maybe three times the rate of most projects I've been associated with, and at probably 6 times the rate of a typical project in this organization. It's pretty high quality stuff, too, in an environment with hideously complex business rules and very high cost for failure in implementing those rules. Frankly, I'm pretty happy about that.

Here's what we've got that works:

1. very senior, very fast developers. (Plug: if they're from Gorilla Logic, as I am, they couldn't be anything else, as that's a primary focus of Gorilla Logic's hiring practice.)

2. dead quiet when it's time to concentrate. I have a private office. I'm not physically in the same state as the users. In fact, I'm two time zones away. When it's time to crank out well-thought-out results, nothing can beat quiet. (For experimental data on this topic and other key contributors to developer productivity, read "Peopleware" by DeMarco and Lister.)

3. good access to the team when it's time to talk. We have web conferencing, IM, telephones, and desktop video conferencing when we need it.

4. requirements people who aren't bound by the need to generate a document to get the requirements to us, who are highly accessible, and who know the domain quite well.

5. management who understands the importance of getting it right, and respects the professional opinions of the team.

The release will probably slip a week. When we're done, it'll be pretty much what they needed, rather than arbitrarily "what we had working on the release date". We might deliver faster with a different management style, but I wouldn't bet my next paycheck on that. If the problem domain was simple enough to allow for stable requirements, they might not need the software in the first place.

That's agile enough for me.

Wednesday, September 16, 2009

"Really Good Programmers"

A young designer/developer/businessman I respect and admire twittered the following today:

"Really good ruby programmers can write code that is so clever that no one less talented than them has a hope of understanding it."

He really should know better.

Really good programmers can, indeed, write code so clever that no one less talented than themselves has any hope of understanding it--but they never do. That's the sort of thing really talented coders do before they become really good programmers. And then, in the code review, their peers tell them to take out the clever bit of code and make it maintainable, thereby vastly improving the code.

A decent piece of software has a lifetime measured in tens of years. During that time, it's likely to be looked at a dozen times for new features, bug fixes, and efficiency updates--not to mention the occasional port. If it took a day to write it initially, it'll probably spend many times that under someone's lens while it's in the maintenance phase. Taking 12 hours to write clear, comprehensible code instead of 8 hours to do something clever will save time in the long run. Is it always worth the extra time? No--but it is often enough that I try to do it every single time I code something.

Strange clever code is fun to write. I write a little self-modifying routine one time, both to prove I could do it, and to solve a timing issue--I counted op-codes and found I could squeeze pattern recognition between bytes on a 19.2kbps serial connection by making the polling routine self-modifying. Nowadays I'd comment it like crazy, and advise that it be removed as soon as CPU speeds increased enough to do so. Back then I wasn't a good enough programmer to know I needed to do that. Hadn't looked at enough of my own code, incomprehensible after 5 years of "rest", to know it was important to do so.

So Jon: educate that Ruby programmer of yours. Someday he'll thank you for it. All your maintenance guys will thank you for it, and you won't have to wait for that.

Wednesday, September 9, 2009

architecture by accident

I’ve been on a number of projects with a common problem set:

  • architecture is deteriorating with time, and was never strong to begin with
  • there is no architect or designer with project-wide authority
  • nobody views this as a problem–including the development team
  • time to add a feature is increasing
  • quality issues continually surface as new features affect older ones

The introduction to Booch/Rumbaugh/Jacobson "The Unified Modeling Language User Guide" makes the case for design modeling thusly:

"If you want to build a dog house, you can pretty much start with a pile of lumber, some nails, and a few basic tools...

"If you want to build a house for your family, you can start with a pile of lumber, some nails, and a few basic tools, but it's going to take you a lot longer, and your family will certainly be more demanding than the dog. ...

"If you want to build a high-rise office building, it would be infinitely stupid for you to start with a big pile of lumber, some nails, and a few basic tools. ... You will want to do extensive planning, because the cost of failure is high. ...

"Curiously, a lot of software development organizations start out by wanting to build high rises but approach the problem as if they were knocking out a dog house."

(The full text is entertaining; go forth and read the whole thing.)

As a developer, there are a couple of approaches I use to at least try to address this:

  • When adding new features myself, try to talk with everyone with code touching mine. Often there is a conceptual design in each area's designer's mind--there just is no globally-available expression of it.
  • I document my own designs with diagrams and written discussion, which I pass around for comment. I try to include global information about the global concept objects I touch. This has the effect of (often) flushing out different views of the responsibilities and limitations of key objects.
  • I transfer design information into javadoc, so the next developer can see it as (s)he codes.

Design is key to success in anything but the smallest projects. I use "success" very carefully here; some more recommended reading:×3f_.aspx
"When an enterprise software application is deployed to production, it’s almost universally considered to be a success. In most other industries, equating completion and success would be ludicrous. After all, few in the construction industry would deem a two-year-old house with a leaky roof and a shifting foundation anything but a disaster — and an outright liability.

"Yet, had the VCF system gone live, almost everyone involved — from the business analysts to the programmers to the project managers — would have called their work a success. Even after the code devolved into an unsustainable mess, many would still refuse to admit that they had failed. The result is a cycle of failure, as dev shops refuse to recognize and correct issues that plague their projects."