Friday, October 12, 2007

Dialing up quality

Quality is not a light switch, it can't be flipped on overnight, or even in six months.  Although the term "quality" differs from person to person, I rather like James Shore's description of Quality With a Name.  He defines quality as having a great design, and that a great design is easy to change.

Furthermore, he concludes:

Great designs:

  • Are easily modified by the people who most frequently work within them,
  • Easily support unexpected changes,
  • Are easy to modify and maintain,
  • and Prove their value by becoming steadily easier to modify over years of changes and upgrades. 

Now that your team agrees on what great design is, reality sinks in when they go back to the monolithic flying-spaghetti-code-monster system and see how far away they are from great design.

Great design and high quality can be achieved, but it takes many individual victories to reach the final goal.  A team can dial up quality, one principle/practice at a time, until the team and the system are one smoothly running machine.

Low hanging fruit

So how do we decide where to begin?  The easiest is the low hanging fruit, pain points that affect developers every day.  Here's some common pain points/smells I run in to:

  • Everyone is afraid to get the latest version
  • "It works on my machine" is your team's mantra
  • Every source code file has at least 3 different coding styles
  • It takes forever to reproduce a defect locally
  • No one knows if the defect is still fixed next week, month, or six months from now

And the list can go on and on.  Once pain points are found, take the top pain point and set a goal to tackle it in the next week or month.  Then schedule a brown-bag lunch to show the problem, how you tackled it, and the principles that led you to these actions.

Show the value

When I want to correct some of these quality issues, I can't tackle the issue in one fell swoop.  Often new ideas have to be introduced a little at a time, where I prove the value as I go.

I can't force unit tests or pair programming on a team if no one sees the value.  If I try it out, show the value, then team members will start to come onboard.

A plan of action might be:

  1. Automate the build locally
  2. Automate the build of the latest version on a build server
  3. Remove all warnings
  4. Add some automated tests to reproduce a defect
  5. Get these automated tests running with the nightly build
  6. Introduce unit tests on new code, running with the nightly build
  7. Introduce some key FxCop rules where we're seeing the most varying coding styles
  8. Gradually introduce other FxCop rules to hit other pain points

Once initial buy-in for values like "feedback" and "maintainability" happens in your team, it's that much easier to introduce other practices that enforce those key values.  Perfect quality is never achieved, but as my dentist told me, excellence is the pursuit of perfection.

Baby steps to excellence

It's easy to get discouraged trying to get 100% test coverage on a legacy app.  A better intermediate step is to get 80% coverage on the class or classes that have the most defects.  Lessons learned from that experience can then be applied to the rest of the app.  But if we tried to tackle the entire system all at once, we wouldn't get far enough to realize the value, and the team would discard the value as impossible to achieve.

By taking small steps toward realizing our goals, dialing up quality one step at a time, we can create a pattern of success take the system to a level of quality that otherwise would not have been imagined to be possible.

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