Tuesday 19 November 2013

More on Technical Debt #1/2

Last year I introduced the topic of technical debt. Technical debt is a debt that you incur every time you avoid doing the right thing (like refactoring, removing duplication/redundancy), thereby letting the code quality deteriorate over time. As with financial debt, it is the easy thing to do in the short term; however, over time, you pay interest on this debt - the code quality deteriorates over time. And as with real debt, it can be used beneficially if managed well.

I thought I'd list a few of the techniques I use to manage debt. I'll list five here, and offer some more in a subsequent post.

1. Reduce the debt before implementation. Passing systems with high technical debt to other teams, such as a systems operation team is generally a bad practice. It should be ingrained in your culture that each team is responsible for keeping the quality of their solutions high. It is reasonable to expect maintenance groups to resist accepting systems that have high technical debt.

2. Some technical debt is acceptable. Sometimes you will decide to explicitly accept some short term technical debt for tactical reasons. Perhaps there is a new component or framework about to be delivered by another group in your organisation, so you’re writing a small portion of what you need for now until you can replace it with the more robust component. Regardless of the reason, part of the decision to accept technical debt is to also accept the need to pay it down at some point in the future. Having good regression testing plans in place assures that refactoring accepted technical debt in the future can be done with low risk.

3. Measure technical debt. If you are serious about technical debt then you must measure it and, more importantly, keep an eye on the trends (which should be going down over time). Keep a log of technical debt that identifies each element.

4. Explicitly govern your technical debt. For your organisation to succeed at reducing technical debt it must be governed. This means it needs to be understood by senior management, measured (see previous point), and funded.

5. Make the reduction of technical debt part of your culture. Technical debt isn't going to fix itself, and worse yet will accrue "interest" over time in the form of slower and more expensive evolution of your system.

As with real debt, technical debt can be used positively if it is well managed. Using the above techniques will help you to manage it.

Read more:
More on Technical Debt #2/2