Thursday, January 1, 2009

More links for my personal research

The following is here for knowledge retention purposes only so be forewarned that it might bore you and you can stop reading now.

Today I've been doing plenty of blog-reading. There are many more things I'd like to read further but I'm out of time. Here are 5 links without notes and 2 links with notes.

The Greatest Invention in Computer Science is "The Routine"

Aside from the invention of the computer, the routine is arguably the single greatest invention in computer science. It makes programs easier to read and understand. It makes them smaller (imagine how much larger your code would be if you had to repeat the code for every call to a routine instead of invoking the routine). And it makes them faster (imagine how hard it would be to make performance improvements in similar code used in a dozen places rather than making all the performance improvements in one routine). In large part, routines are what make modern programming possible.

the problem with routines: they only take a minute to learn, but a lifetime to master ....

* How long should this routine be? How long is too long? How short is too short? When is code "too simple" to be in a routine?
* What parameters should be passed to this routine? What data structures or data types? In what order? How will they be used? Which will be modified as a result of the routine?
* What's a good name for this routine? Naming is hard. Really hard.
* How is this routine related to other nearby routines? Do they happen at the same time, or in the same order? Do they share common data? Do they really belong together? What order should they be in?
* How will I know if the code in this routine succeeded? Should it return a success or error code? How will exceptions, problems, and error conditions be handled?
* Should this routine even exist at all?

One thing I'll add is this. I LOVE STUBS. That's where I decide for a subroutine on a test value that will get sent back to the calling method until I have time to properly design/write the subroutine. My favorite phrase is "Hello World from ". For example a subroutine called MyNamespace.MyClass.MySubroutine will send back "Hello World from MyNamespace.MyClass.MySubroutine 001" the first time. As new test versions are built and the code gets improved I might increase the number so it now says "... 002", then "... 003", etc.

It is the job of a good software project manager to recognize the tell-tale symptoms of this classic mistake and address them head on before they derail the project. How? By forcingencouraging developers to create a detailed list of everything they need to do. And then breaking that list down into subitems. And then adding all the subitems they inevitably forgot because they didn't think that far ahead. Once you have all those items on a list, then -- and only then -- you can begin to estimate how long the work will take.

Until you've got at least the beginnings of a task list, any concept of scheduling is utter fantasy. A very pleasant fantasy, to be sure, but the real world can be extremely unforgiving to such dreams.

Johanna Rothman makes the same point in a recent email newsletter, and offers specific actions you can take to avoid being stuck 90% done:

1. List everything you need to do to finish the big chunk of work. I include any infrastructure work such as setting up branches in the source control system.

2. Estimate each item on that list. This initial estimate will help you see how long it might take to complete the entire task.

3. Now, look to see how long each item on that list will take to finish. If you have a task longer than one day, break that task into smaller pieces. Breaking larger tasks into these inch-pebbles is critical for escaping the 90% Done syndrome.

4. Determine a way to show visible status to anyone who's interested. If you're the person doing the work, what would you have to do to show your status to your manager? If you're the manager, what do you need to see? You might need to see lists of test cases or a demo or something else that shows you visible progress.

5. Since you've got one-day or smaller tasks, you can track your progress daily. I like to keep a chart or list of the tasks, my initial estimated end time and the actual end time for each task. This is especially important for you managers, so you can see if the person is being interrupted and therefore is multitasking.

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